One Planet Reno

Take Yourself Over to www.build-green.com/blog

2010-10-03T17:38:00.001-07:00

We've updated our website, and with the update have migrated over the blog. This blog address is no longer being maintained or updated. For up to date information on the One Planet Reno please visit www.build-green.com/blog

Healthy Enough to Live In

2010-09-08T05:06:00.000-07:00

Although our primary area of focus in design and on this blog has been in crafting an environmentally responsible house, we are also planning on making this one of the healthiest urban renovations anywhere in North America.

Most people do not realize that a new house or a typical major renovation is laden with all kinds of nasty chemicals – volatile organic compounds like formaldehyde, pthalates, hormone disruptors, allergens...the list goes on.Formaldehyde is particularly omnipresent in our built environment. We all remember the use of formaldehyde from grade 10 science class to pickle frogs (that and my cute lab partner is about all I remember from grade 10 science). Formaldehyde is a very strong preservative, and beloved by paint manufacturers, adhesive makers, and chemical companies cum building materials suppliers of all stripes. It is also a known carcinogen and a potent allergen.

To cut down our exposure we are using zero VOC paints, natural oil and wax floor finishes (typical urethane floor finish has some of the highest emission rates of any building product), formaldehyde free sheet goods, and keeping a careful eye on any caulking and sealants used on the project.

Other healthy house initiatives include:

a whole house water purification system,
a very efficient heat recovery ventilator to bring in fresh air, and
a HEPA filtration system to help clean any of the nasties out of the air.

We’ll be reporting more on our healthy house initiative as the project progresses.

Unvented Roof Space/Evening Fun with the Building Code

2010-08-25T18:30:00.000-07:00

As per our previous post, one of the challenges with the City granting our permit was that we did not want to vent the joist space between our 3rd floor ceiling and the roof deck. We are trying to achieve R85, which we can do with 16” of Roxul in the stud space and 3” of re-used/salvaged XPS outboard of the roof membrane. The outboard XPS not only adds thermal performance but will also significantly increase the longevity of the roof membrane. The challenge with this section is that if you put a vented space between the top of the Roxul and the roofdeck/XPS – then the XPS no longer contributes to keeping the house warm, and we are left with an R60 roof.

Ontario Building Code (OBC) 9.19.1.1 requires a vented space between the insulation and sheathing except where it can be shown to be unnecessary. OBC Appendix A-9.19.1.1.(1) explains that the venting is required to limit moisture induced deterioration that can arise from imperfections that normally exist in vapour and air barrier systems. The Appendix further explains that the exception to venting accommodates specialized ceiling roof assemblies that are sufficiently tight to prevent excessive moisture accumulation.

Typically we think venting roof space is a good idea as we've seen too many moldy attics and too much shoddy construction to think unvented roof spaces should normally be standard practice. But this is no standard house, with a much better then average design, and a commitment to details by everyone involved.

So – we called on our good friends at Halsall Associates to help us develop a ceiling detail that would be sufficiently tight to achieve this. The following details describe the assembly. The City has accepted this – so we are good to go. (Note – this assembly is specifically for our house – and may or may not be right for another project, you really need a good Building Scientist for this kind of detail)

Specialized Ceiling-Roof Assembly

The following specialized assembly is engineered specifically for 125 Third Avenue and does not require a vented cavity below the roof sheathing to control moisture.

The design consists of the following, from top to bottom:

·      Surface Finish - Wood roof deck or aggregate (varies over the roof area)

·      Permeable water resistive fabric (Tyvek or equal)

·      3” extruded polystyrene (R15)

·      2 ply modified bitumen membrane system

·      Nail applied cover board (compatible with, and part of the membrane system)

·      3/4” tongue and groove plywood roof sheathing

·      16” I-joists, cavity filled with mineral wool insulation (Roxul) (R60)

·      Tyvek (or equivalent) vapour permeable air barrier over top of wall header prior to installing I-joists. Seal to exterior sheathing and to ceiling polyethylene to protect against wall cavity air rising into the ceiling space. Lap and seal all joints.

·      15 mil ceiling polyethylene vapour barrier with all joints lapped and sealed with acoustic caulking, and acoustic caulking applied at every joist to seal staple and screw penetrations. Lap and seal the ceiling polyethylene to the wall polyethylene vapour barrier.

·      Foil faced drywall with foil facing down; joints are to be caulked and then taped with foil tape. This is also to be sealed and taped to the wall polyethylene.

·      2” x 2” furring along the bottom chord of every joist, bedded in acoustic caulk prior to nailing

·      3/4” strapping perpendicular to joists, screws to penetrate furring only

The above assembly is to be air tested with a blower door and smoke to confirm the quality of the air barrier assembly as a quality control measure. We understand the City Building Inspector will be invited to witness this test.

·      1/2” drywall finish

·      Finally, the cladding materials at the ends of the roof I-joists are to be vapour permeable; mineral wool insulation with Tyvek is to be provided instead of foam insulation.

Wonderful World of Windows

2010-08-24T04:25:00.000-07:00

Achieving an exceptional envelope could be quite cost effective if you didn’t like windows (surprising how often we hear engineers advocate for that solution). However, windows are rather important to the quality of life inside the house, so we are stuck with them.

We had always assumed we would use fiberglass windows from the beginning of the project with the only serious competitor to this being wood windows with the euro-style vented aluminum cladding on the outside. The more research we did, the more confirmation we received that fiberglass is indeed the best option for ultra efficient residential envelopes.

There are a number of manufacturers in the marketplace, but we really boiled ours down to 2 options – Thermotech Fibrerglass Fenestration from Ottawa ( http://www.thermotechfiberglass.com/), and Inline Fibreglass from Mississauga (http://www.inlinefiberglass.com/). As an aside, we also really liked the offering from Serious Windows (www.seriouswindows.com) but they did not have any kind of local representation. Both of these manufacturers build exceptional windows and it was hard to choose between them. In the end, it was the local dealer for Inline – confusingly called Thermotech Windows Ltd. ( http://www.thermotechwindows.com/index.html )– that was the deciding factor. We have worked with this dealer in the past on projects with good success and Arbnor helped us through the process. Inline is a much higher volume manufacturer than Thermotech so they can be slightly more cost competitive, but maybe not as flexible. The advantage of the local dealer is that he has some pull at the factory to ensure our relatively small order is not lost (we hope - Arbnor don't make us revise this post!).

If you are not familiar with the benefits of fiberglass, just go the Inline website and review the information there. This is not just sales talk - but is backed by good research from Building Scientists.

Since all orders are completely custom, we were able to select specific glazing for the different faces of the house. All windows are triple glazed – meaning 3 sheets of glass separated by a “warm edge spacer”, which is a non heat-conducting material. The spaces between the sheets are filled with Argon gas to further reduce thermal conductivity. Argon is a naturally occurring gas with no serious environmental impacts. On the southern façade, we chose coatings on the glass that would optimize heat gain from the sun. On the North we chose coatings that minimize thermal loss radiating back out. For our house, the East and West get very little direct sunshine – but they do get some, so we opted for solar gain glass on those walls as well. These windows perform very well. At the centre of the glass they are around R8 and the overall performance of an average sized window is around R5.

These windows are expensive. Our house is severely limited by code for windows on the East and West walls, and we are trying to limit the windows on the North for energy performance – so we really don’t have that many windows. In total we have 23 windows, averaging about 13 sq.ft. Each for a total of 300 sq.ft. Of window area. (This excludes our awesome folding glass wall on the south face – see other post). The total cost for our Inline windows is around $29,000. That works out to about $97/ sq.foot of glass area or an average of $1250 per window.

For comparison purposes, we asked Thermotech Windows to price our exact package in PVC from one of their other suppliers who provides “high quality” PVC windows (high quality and PVC don't really ever belong in the same sentence, hence the use of quotation marks). The price came back at $17,000. It is not an apples-to-apples comparison because there were a few windows which would have to be smaller if they were in PVC because the frames are not strong enough to hold the triple pane glazing unit over a long span, and the glass does not have a warm-edge-spacer. However, we can deduce that the premium for fiberglass is in the nieghbourhood of 60%. The thermal performance of the fiberglass windows is not 60% better than “high quality” PVC on the day they are installed, but they may last twice as long and will keep their performance much longer than the PVC windows. Also the use of PVC windows would run counter to our 'No Vinyl, That's Final' maxim that we try to use for all of our projects. Our research says it is worth the investment, and there is no way we could get near the Passive House standard without them. We will post some pictures in 10 weeks or so when they arrive.

Warning: Do not drink this post...

2010-08-19T10:55:00.000-07:00

For those of you who are faithful blog followers (and really, who isn’t?), you’ll recall that we have spared no expense and many hours of design time to create an effective rainwater harvesting system. We’ll be capturing rainwater off the flat roof and bringing it down to a large cistern in the basement (see earlier posts for more details). Our intention was to use that non-potable water for flushing toilets and for outdoor hose bibs for garden irrigation and hosing down dirty kids and bikes.
Although the City recognizes the sustainability benefit of using non-potable water, they are not allowing us to have a hose bib at grade. The fear is that we might run a sprinkler (can’t imagine doing that), or run a hose and a neighbour kid would drink the non-potable water, get sick and sue the City. In commercial projects we’ve been able to use locked hose bibs, meaning only someone with the key can open them up. For this project in a residential neighbourhood the City is not seeing that as an acceptable solution.
When time is ticking and we have crews on site we are forced into accepting the City’s decree and won’t be having a hose bib at grade. We just can’t afford the extra time to hold up the permit. We’ll still be having the cistern, using the water to flush toilets, and will have a locked hose bib on the roof to wash solar panels and water the veggies, but unfortunately will not be using it to water plants at grade. It is unfortunate that the chilling fear of litigation gets in the way of good green practice. What we are proposing is little more than a huge rain barrel. People have (thankfully) been using rain barrels for a very long time, using them to water the garden, and miraculously we don’t have neighbour kids dropping like flies from drinking stored rainwater. In the end the fear of liability means we’ll be using treated and pumped water to get the dirt off our mountain bikes after filthy fall rides.
This is a symptom of too much litigation, but also the fact that municipalities are on the hook for joint and several liability in Ontario. That means if they are found 2% liable when a kid gets sick, they could be stuck paying the whole bill. This unnecessary exposure to liability puts a chill on all kinds of innovation. For that reason we are supporting AMO’s push to reform municipal liability – see: http://tiny.cc/k7d07 for more scintillating details.

Get Yer Permits...Red Hot Permits...

2010-08-19T10:54:00.000-07:00

With modern times and an innovative project comes bureaucracy and bureaucratic challenges; the One Planet Reno is (sadly) not immune. We feel very fortunate to have a good relationship with the City having worked on a series of successful and innovative projects here in Ottawa, as well as having developed and delivered a training program on green development for the Development Approvals staff. Even with that going for us, we’ve still had four significant permit challenges:
A challenge to the use of hose bibs with our rainwater harvesting system;
Concern about our non-standard insulation/non-venting for the flat roof;
Concern about the mechanical system and pre-heating of domestic hot water with solar thermal (would not have been a challenge if we were using a standard off-the-shelf and pre-approved systems); and
Disagreement about zoning interpretations.
We’ll blog about each of these as they come to resolution with plenty more detail to follow.

Love Your Neighbourhood Forest

2010-08-09T05:20:00.000-07:00

Just returned from a very fine wilderness canoe trip to Parc de la Verendrye (see pic below) – a little known gem just a few hours north of here with 4000 lakes, ample sandy beaches, and a few delightful spots of whitewater. Our trip of canoeing, lounging on white sandy beaches and hammocking (could that really be a verb) was unfortunately marred by having to drive through some nasty clearcuts while leaving the park. Although there has not been the same passion for forestry issues in eastern Canada as there has been on the west coast, the issue is just as important. On many of our commercial projects wood products make up only a tiny percentage of the materials used in construction, but for the One Planet Reno it will play a major role.

One of the reasons we chose the One Planet framework as an approach to the house renovation was that we liked the holistic view of sustainability. I recall a couple years ago an article that was burning up the blogosphere by Joseph Lstiburek titled Its the Energy Stupid, making the claim that building green was all about saving (operating) energy. We’re with Joe when he takes shots at tall glass LEED buildings that are energy hogs, but disagree that it is just about energy. It is also hard to claim true green status when the building is largely fabricated out of wood from clearcuts.

To ensure that our wood is coming from sustainable sources we’re prioritizing the use of salvaged wood wherever available. ‘Salvaged’ wood means wood that has already been put to good use (e.g. Holding up a barn), and now is cleaned up and given a second life. Failing availability or cost effectiveness of salvaged wood we’ll be using FSC certified wood from as local as possible. FSC stands for Forest Stewardship Council and is the gold standard for certified wood in Canada. Feel free to check out www.fsc.org to learn more about why FSC is the shizzle. It is based on 10 principles that range from respecting indigenous rights to protecting biological hotspots.

We're still looking for locally available FSC engineered joists so if anyone has any leads we'd be happy to hear about it.

Demolition Time

2010-08-08T17:38:00.000-07:00

For those of you who love mould, cat urine, and insect damage this post is for you. We have truly started demolition and it is a spectacular mess.

The two certainties of renovation on this scale with a property of this age (and neglect) is that things will often take longer and cost more than anticipated. We certainly underestimated the amount of moisture damage that we would find, and the volume of waste is much higher than anticipated. In several rooms of the house there was drywall over strapping over wood paneling, over plaster and lath. The roof appears to have 3 layers of asphalt shingles over remnants of cedar shakes and it has leaked substantially. The entire main roof has mould and water damage, the floor boards in the finished area of the attic are saturated with pet urine to the extent that it makes your eyes water (if anyone wants some old beige carpet reeking of cat urine and infested with mould spores give us a call - sure to go quick). The back room, which we planned to remove, is only standing because of drywall and an exterior 7/16” sheathing, because the entire core of one wall has turned to mush. When it rains the water runs right through it. We also can’t interest any local salvage companies to take our trim, stairs, or other details. They claim they have enough of this in stock and it does not move quickly. We did find some huge pine boards though as sheathing – one 21” wide. We will have to pull that off for use elsewhere.

The implications of all this for our One Planet action plan is that it is going to be very challenging to meet our diversion targets.

plaster, drywall, old paneling all has lead paint so we could not do anything with it – more layers = more landfill.
The back room is now going to be removed by a backhoe because there is nothing salvageable and it is not stable.
Some of the wood we planned to salvage is mouldy and or soaked with urine – so it adds to the landfill pile.
No salvage opportunities for stairs and wood details – more for landfill.

Our timeline and budget are at risk. We estimated $15k for demolition and have spent $10k already and we are about 1/3 done. We have removed 70 cubic yards of waste to landfill as of today.

We have attached a couple of pictures to remind people why renovation is always more challenging than new build.

These aren't too shabby either...

2010-07-30T06:07:00.000-07:00

This isn't directly related to the One Planet House Reno but we did find it interesting - Architect Magazine recently polled a collection of US green building folks for the best green buildings of the past 30 years. You can check out the results here - http://www.architectmagazine.com/green-building/web-exclusive-the-g-list-survey-of-architecture.aspx
We were pleased to see Dockside Green and BedZED being mentioned in that short and exclusive list - both projects we've had the pleasure of being associated with. We fully anticipate the One Planet Reno house to be up there when the next survey is conducted!

Now For Something Controversial

2010-07-20T10:27:00.000-07:00

We’ve been looking at a lot of net zero, near net zero, and Passive House buildings over the past year or so to learn lessons and get inspired for the One Planet Reno. One thing you cannot help but notice on many of these projects is the predominant PV and solar thermal panels often times extending past the building envelope. New building projects often feature oversized roofs or even (heaven forbid) monster garages to give the owners sufficient roof space to meet their loads. As committed greenies and green power advocates the sight of a prominent solar panel is always a welcome sight, but we certainly recognize that this is far from being a universally appealing aesthetic. We have also questioned whether this is going to quickly look dated as new thin film technology and building integrated systems come in the market making solar sleeker, less obvious, and more aesthetically flexible. Is today’s solar panel going to look like the equivalent of a Commodore 64 plopped on the roof as the defining architectural feature in a decade?
We need to be additionally sensitive to this issue as the One Planet Reno is located in an existing heritage neighbourhood where there are some resident sensitivities about maintaining the heritage character of the neighbourhood. Something about a large PV array that doesn’t quite scream heritage to us. We’re not slavish to heritage-based design, and will end up with a modern looking house with heritage elements, but we are looking for ways to be appealing to our new neighbours and recognize their concerns.
So our answer to this issue is to load the panels primarily up on the back half of the roof (effectively the 4th story). From our side of the street the panels will not be readily visible, and from the other side of the street they certainly will not be the predominant visual feature. We’re hoping there will still be some significant green cues that draw attention to our sustainability aspirations, while crafting a design that will have lasting resonance.
For an illustration of solar with some questionable aesthetics see below.

Nice Rack (Solar PV of course)!

2010-07-14T05:36:00.000-07:00

As we have talked about in other posts, the roof serves several purposes – capture solar energy, capture rain for the cistern, grow food, a spot for evening rooftop soirees, and if all goes well, keeps the house dry.

We have tried every conceivable way to capture more sun on the roof for energy production, but our roof is small, slightly off south orientation, with large beautiful trees to the south making it very challenging. Makes me think of the recent article I read of a 'net zero' home being built in suburban Toronto where they added a four car garage to have more roof space for the PV. The more solar we put up, the more it shades itself. Below is an image from Google Sketch-Up of the roof taken from our shadow studies at noon on December 21st (sun at its lowest point during the year around 21 degrees) and at noon on June 21st (sun at its highest point at around 68 degrees). The big cylinder is an approximation of our neighbor's tree with full leaves (trust me, the tree looks a lot better in real life). This is not the case in December, but any shading hurts the solar performance.

What you see in the images is a large array of photovoltaic (PV) panels on the slope over the stairwell at 35 degrees, which is the ideal angle for PV on an annual basis in Ottawa. 10 panels at 230 watts per panel will fit on this slope, then another large rack at the back – at 60 degrees for the solar thermal, with another 5 PV panels above them at 35 degrees again. Annually, we will generate roughly 5,900 kwh of useful heat from the solar thermal, and roughly 3,500 kwh of electricity from the 15 panel (3.45kw nominal output) PV array. This is a total of 9,400 kwh/year of solar energy captured.

The capital cost of the PV system will be around $33k. If you do some math for maintenance costs, and degraded panel performance over 20 years, the PV costs about 50 cents per kwh to produce. This compares with the solar thermal at about 18 cents per hwh of heat. The big difference is that the Ontario FIT program will pay us 80.2 cents for our PV generated – or roughly $2800/yr. This certainly puts the economics in favour of PV.

Gettin' Thermal, Solar Style

2010-07-05T17:42:00.000-07:00

We talked about the fundamental challenge of the net-zero energy in another post, but we wanted to update you with our loads, and show you how solar thermal panels will contribute to lowering our carbon footprint.

The table shows a month by month estimate of the thermal loads for the One Planet Reno for space heating and domestic hot water (DHW). We've been able to keep the loads for space heating pretty teensy. Using the modeling Malcolm did with the Passive House software we're figuring roughly 29kwh/square meter. The DHW loads are estimated based on our families current consumption habits and improving the flow rates in some key fixtures. Together you can see the total thermal load we need to meet.

We are working with Chris Weissflog of Ecogen Energy Inc (check out http://www.ecogenenergy.ca)
for the solar themal system. Chris ran some modeling for us to see what contribution could be made with a solar thermal system and storage tanks, given our roof orientation and space limitations. He ran several scenarios and costed a 3 panel and a 4 panel system. Here's the shakedown (for those keeners check out the spreadsheet below) with a 4 panel system we can meet a significant portion (63.4%) of our thermal energy needs - but we do have a lot of excess heat in the summer. (We will post more about how to deal with this “waste heat” in another post - sneak peek - it's not a hot tub.)

To keep our heads firmly planted in economic reality – the 4 panel solar thermal system (120 evacuated tubes) will cost around $22,000 installed, complete with storage, and maintained for 20 years. This does not include a means to distribute that heat to the house or the DHW system. Assuming 20 years of energy production, the cost per kwh of heat is 17.7 cents for a 4 panel system versus 19.3 cents for a 3 panel system. The added panel gives us around 900kwh of useful energy per year for only 9.1 cents per kwh.

So – we are going to pay about 18 cents per kwh of carbon neutral thermal energy, vs. Ontario’s grid energy at 8 cents per kwh for dirty power. It is certainly a high premium, but it appears to be our best path to meeting the zero carbon principle.

Getting to Zero

2010-06-26T05:00:00.000-07:00

The average Canadian single family dwelling uses an unfortunately high total of 238.9 kwh/square meter of house area. For our 180 square meter house (1900 sq ft), this would equal 43,002 kwhrs/year broken down as follows:

Household Energy Use
Use Consumption %
space heating 28613 kwh/year 67%
hot water 6663 kwh/year 15%
appliances 4942 kwh/year 11%
lighting 1948 kwh/year 5%
space cooling 835 kwh/year 2%
Total 43002 kwh/year

There are really only two practical ways to make energy on a tight lot in the city in Ottawa– solar photovoltaic (electricity) - called PV, and solar thermal (direct heat from the sun). There are other renewable options for space heating – like burning bio-mass (wood, grains, waste etc.) that can help with space and water heating, but electricity that meets the “zero carbon” concept pretty much needs to come from the sun given all the constraints in the city.

The PV technology on the market today varies in terms of efficiency to turn sunlight into electricity. A good German panel that is roughly 1.63 square meters (17.3 sq.ft), has a nominal output of 230 Watts. “Nominal output” means that when the panel is brand new, and in direct sunshine it will produces 230 Watt hours in an hour. On average throughout the year, Ottawa gets about 3.8 hours of useful sunlight per day that can be turned into electricity. Not all that electricity can be used though, first it needs to be inverted from DC to AC and run through a meter etc. This can add up to 25% in losses. After some math, we found that for each kW of nominal output on our roof, we can generate about 1037 kwh/year of electricity. When you string the PV panels together to make an “array”, you need to add some space between panels for clearance and venting plus space for wire runs. We have found that we require around 8.5 square meters (90 sq. ft.) for each kW of nominal outuput.

So.........a typical house of our size uses 43,002 kwh/year
Divided by 1037 kwh/year output per kw of nominal capacity
Equals 41.47 kw of required capacity
Multiplied by 8.5 meters per kw
Equals 352.5 square meters (3746 sq ft) of south facing roof space.

The cost for this system would be higher than the renovation budget for the entire One Planet Reno project, and our entire lot is only 242 square meters (and a good chunk of that is in the shaded backyard which would be almost useless for PV). The roof is just 640 square feet, of which 20% of it is shaded in the spring/fall. Needless to say, this is not an approach that can work on our project. This helps explain why all projects that attempt zero carbon, or net zero energy, must drastically reduce the energy demand first, and then turn to renewable energy production. That is why we are using the Passive House approach to energy efficiency and leaving the beer fridge behind at our current house.

We will post our projected energy profile later, once we have the solar thermal system designed.

Death of the Buffer Zone

2010-06-24T04:19:00.000-07:00

A much earlier post discussed the benefits of a Dynamic Buffer Zone (DBZ). We became very attached to the concept, and for a long time worked to ensure our plans could include it. Sadly it is not going to work in this project. The energy modeling we did indicates that the DBZ does not have strong effect on the energy performance of the house. It has advantages with respect to thermal comfort at the front of the house, but overall is not a game changer. It is however a budget-breaker. We priced several options to have 2 sets of doors at the front of the house to create the DBZ and still have flexibility of how we use the floor space. We thought people looking to emulate our design may benefit from our research.

Our cheapest option, that was still reasonable in energy performance were very large sliding fiberglass doors – 4 panels, each panel about 4’ wide. The centre panels would open and give us almost 8’ of clear opening. However, the air leakage performance on these is not very good over time because they ride on the seal. Each set of doors would be in the $7-10k range depending on the details and which manufacturer we chose, plus installation (for example - www.inlinefiberglass.com).

Next up was to look at fiberglass tilt-and-turn doors to give us the long term air sealing, but the swing on the doors takes up way too much floor space inside. The cost was closer to $12k per set of doors.
Then we started looking at some of the “lift and slide” options on the market. These doors slide open like the door on a mini-van – they pop out and then run parallel to the sill, so they are not riding on the seal. The come in very interesting configurations including the ability to put them into a pocket, or have 3 panels stack on top of the 4th to allow a full 12’ clear opening. The price ranged from about $14k to almost $18k per set of doors. The air sealing was very good on these units relative to the two cheaper options.

Finally we looked at folding doors. The most commonly marketed version out there is called NanaWall – and they have great animations on their website (www.nanawall.com). These doors fold out of the way to create a large clear opening. The challenge for us was that most manufacturers gear this product to the coastal climate. They are not too worried about air leakage, and have very little understanding of solar gain glass (these are on the south side of the house and we want them to let in as much heat as possible during the winter). After lots of searching, I sorted out that this is all German technology, and there really are only a few parent companies who are all doing the bulk of the manufacturing in Germany. There is one Canadian manufacturer who builds folding door systems in Canada - (www.dynamicwindows.com). These doors also range in price from around $14k to about $18k depending on the manufacturer and options for a clear opening of over 13’.

So – we were faced with a pretty tough decision. We love the idea of the DBZ, and think it would add to our thermal comfort, but it is not getting us closer to Passive House, complicates our interior layout, and costs a fortune. In the end we decided that we need the money for other energy saving concepts more than we need a DBZ.

However – our search did yield a pretty amazing set of folding doors to allow us to open up the front of the second floor fully to the balcony. This was always our hope – and these doors are going to make it happen. The people at Meyers Windows – located in Vancouver, but manufactured in Germany, understood our need for air sealing, solar gain glass (Solar Heat Gain Coefficient of 0.6), sound isolation, and thermal performance (R5.26 which is spectacular for glass doors). They had experience working on passive house projects in Europe and pretty much understood everything I needed. They were even able to provide the door frames in FSC certified wood. (see www.meyerwindows.ca)

Here is an elevation drawing of the doors. The right hand panel is a swing door, hinged on the right. The 4 left panels fold together and stack to the left.

You Can't Talk PassiveHouse without Talking Insulation

2010-06-18T05:23:00.000-07:00

Time to talk insulation! The Passive House Planning Package energy modeling showed us that ideally we need to get our wall section thermal resistance toward R50 on the existing house, and closer to R60 on the addition (we have more room to play on the addition as we can put insulation on the exterior as opposed to having to eat up floorspace). We have been playing with a variety of options to see how we can achieve this, without sacrificing too much floor space. The existing house is just under 20 feet wide, and it is considered “legal non conforming” - meaning that it does not meet the current zoning regulations for set-backs, but it is allowed.   We are not allowed to make the house any wider, and we want to keep the red brick exterior anyway. Therefore, all our insulation must be added to the interior.

A 20 foot wide house is not that easy to lay out functionally. Once you put a staircase in, and some circulation space to get past the stairs, throw in a sofa and your rooms are getting pretty narrow. Our desire to make very thick walls certainly compounds this problem. Too much insulation and we'll end up with the ecofreako version of Merzbau. Our desire to use low embodied energy insulation, which have lower R-values per inch as compared to petroleum based foams makes this nearly impossible. Soooo - we need to make some compromises.

With the existing balloon framed wall construction, there are only really only 2 options available for insulating the wall without removing all of the interior pine sheathing. We either blow in a fibrous insulation - like Cellulose or Fibreglass, or we fill the cavity with foam. The challenge with anything fibrous is that we can’t guarantee that it won’t get wet from the outside.   With foam, we are not worried about the moisture, and we get the very desirable effect of creating an air barrier at the exterior wall.   Our plan is to use Icynene Pour and Fill formula (see- http://www.icynene.com/icynene-insulation/ - editors note: Hey Icynene, How about a sponsorship?). The blowing agent is not an HCFC, so the global warming potential is much lower than other foams we had considered.

We need much more insulation that we can achieve with foam, so we looked into several options. The reality is, that we simply do not have sufficient space to get R50 from fibrous insulation alone – we need something with more thermal resistance per inch.   So, we are going to rely on polyiso for the much of our insulation in this project (see http://www.pima.org/contentpage/ContentPage.aspx?ModuleID=5&SubModuleID=45) . This is another type of foam that has low global warming potential, but great thermal resistance. It is far from a perfect solution, but we think it is the best compromise of all our objectives.

The sections below are sketches of two of the wall types we will use. One is for the new construction addition and one is for the retrofit of the old part of the house. We need to have several versions of the wall section for the older part of the house because there are places that we simply can’t accommodate a 17” thick wall. We'll have to keep our contractors on their toes as this is not your standard construction.

85 Year Payback for Cistern

2010-06-16T05:21:00.000-07:00

We have been working on the One Planet Reno water principle in order to ready the non-potable (meaning not drinking water) water system for the building permit. The Building Code allows us to use rainwater for toilet flushing, but also has provisions to ensure we don’t contaminate the city's drinking water from our cistern. We also need to identify the pipes as carrying non-potable water used only for sewage conveyance.

The easist way to avoid back contamination is to not connect the systems. However, if the cistern is dry – we still want to flush the toilets (the odour is already often a serious issue in the can, not being able to flush could be a marriage breaker), so we need a way to have potable water as back up. You could do this by filling the cistern part way with potable water if it gets too low, but that would take capacity away when the rain does come. In Ottawa, most of our rain comes in the summer and it can come in short monsoon type events. Therefore we really want all the capacity available. The other alternative is a series of valves that protects the potable connection from any back contamination from the non-potable water. See below for a schematic borrowed from Rainwater Management Solutions that is basically the system we propose to use. We will post the final design schematic and specs later.

These important items add cost. The current estimate for this non-potable water system is around $7,500. Considering the price of water in Ottawa is $2.76 per cubic meter (including the sewer surcharge) we would need to save 2,717 cubic meters of water for this system to pay itself back. Our toilet flushing will require somewhere less than 32 cubic meters per year - so after 85 years of toilet flushing we will break even (either that or we need to start using the can a lot more to justify this investment). The problem in this equation is not the cost of the non-potable system, but how incredibly cheap potable water is in Canada relative to its global scarcity.

We have also posted the calculations to show you how we arrived at the cistern size and tested to see if we could capture enough water in the summer to carry us through the winter.

We have been involved with several commercial and multi-unit residential projects that have done non-potable water, but the city of Ottawa official I spoke with did not think any residences had such a system. We will see what they think of the design in the coming weeks.

Now What's Under Here?

2010-06-14T17:30:00.000-07:00

With a little help from Scott's kids, we smashed some holes in the old plaster and lath to confirm the construction of the existing house. We had guessed it was going to be balloon frame with 1” pine sheathing on the outside, based on other renovations of houses around the same vintage. It turns out that it is balloon framed, but has pine sheathing on both sides of the stud cavity. This is another common method in old Ottawa homes.

So – the wall section is as follows, from outside to inside

Brick
Slight air gap
1” pine sheathing
True 2”X4” balloon framed on 24” centres
1” pine sheathing
Paper
Vertical lath (3/8 to 1/2”) on 12” centres
Horizontal lath at roughly 1/4” spacing
Plaster.

We had been studying several options for air sealing that involved using a 1-2” layer of closed cell foam – to minimize the use of foam, but still get its most important advantage. However, with the sheathing on the inside of the stud bay, this would require us to remove most of these boards to spray the foam. That seems like a waste of good structure to us (likely some additional bucks as well to remove those). So – this is one more strike against closed cell foam for the project. We are going to look at the Icynene pour-and-fill options for the cavity. More to come on proposed wall sections and the latest challenge to get an R50+ wall, with low embodied energy, and still have room inside the house to live.

Why does everything need to be so tricky?

2010-06-14T17:24:00.000-07:00

Malcolm Isaacs used the Passive House Planning Package to model the One Planet Reno. The results were very useful, and a bit disheartening as we learned it would be a heckuva challenge to achieve the stringent standard for retrofits of 25kwh/m2.

In general terms, we simply have too many constraints on the tight urban lot. We can only gain solar radiation on the upper two floors of the south façade due to shading of adjacent houses. In January and February, given that our “south” façade is actually 30 degrees east of south, we simply can not get enough BTU’s from the sun to lower our heat demand. Malcolm modeled the original wall sections as posted earlier before the great foam epiphany, and while we still thought we had to have non-combustible construction. He modeled higher thermal resistance in the walls, floors, roof and windows to see what it would take to achieve 25, and concluded that the cost and the loss of interior space is going to make it an unfavorable option (thought about eliminating the bathrooms to save on space and reduce water consumption, but the 'ol backyard solution is going to be challenging with all that dog poo out there). Depending on the choices we make, we should get below 30, but it is going to take a breakthrough to make 25.

Malcolm provided us with a great spreadsheet to plug in costs so that we can see the price of saved energy of proposed upgrades to the section. This analysis helps show us that going beyond R70 or so on the roof has diminishing returns and we are better to invest in the walls. It also shows us that diligence in air sealing will pay off well, and that the proposed imported HRV is probably going to be worth the investment. We are going to re-work the wall sections with what we know now, and have Malcolm update the model for us. We're going to try to figure out how to post the report so stay tuned.

Sustainability Action Plan

2010-06-09T16:46:00.001-07:00

Sustainability Action Plan (SAP) for the One Planet Reno
One Planet Communities is a network of earth’s greenest neighbourhoods, where people can live a healthier, high-quality lifestyle within a fair share of our planet’s resource.

For our renovation to be considered for endorsement as a pilot project under the One Planet Communities program we need to create a Sustainability Action Plan (SAP). This SAP outlines a high level strategy for the project related to each of the 10 Principles.

The One Planet Framework A holistic approach for true sustainability

The One Planet framework was devised by BioRegional to help developers think holistically about sustainability and create places where living and working within a fair share of our planet’s resources is easy, attractive and affordable. For more information on the framework and the principles visit www.oneplanetcommunities.org (we'll be posting more information on the program on the blog shortly).
BioRegional uses 10 One Planet principles to help developers create places where living and working within a fair share of our planet’s resources is easy, attractive and affordable. The One Planet approach is flexible and recognizes the importance of understanding the local context, and the unique sustainability challenges faced, when developing solutions.

The One Planet Reno is applying the 10 principles at the scale of one family and one house, with the aim of reducing the consumption patterns of a Canadian family to global sustainable levels.

Zero Carbon - big time reduction of energy consumption and Al Gore approved photvoltaics on the roof
♣    Reduce the heating demand through passive solar design, super-insulation, and superior windows. The target is to lower the heating demand to less than 25ekwh/m2, achieving the Passive House Standard for retrofit projects.
♣    Eliminate space cooling.
♣    Eliminate a conventional furnace and disconnect the house from the Natural Gas infrastructure
♣    Use a super efficient Heat Recovery Ventilator for ventilation, coupled with a small heating coil to provide space heating.
♣    In the cooling season, the house will be designed for effective natural ventilation
♣    Half of the domestic hot water load (DHW), and a portion of the space heating needs will be met through an evacuated tube solar thermal system
♣    A wood-burning appliance will be employed for additional heating capacity, and wellbeing during the peak-heating season. Wood will be sourced from local sustainable sources.
♣    A grid tied photovoltaic array (PV) will generate sufficient energy on a net annual basis to offset the equivalent amount of grid energy require for fans, pumps, DHW, lights, and space heating.
♣    The grid-tied PV array will be expanded over time to offset the equivalent amount of grid energy required for all plug loads by 2020.

Zero Waste - reusing and recycling building waste, composting, less packaging
♣    Approximately 70% of the existing building (by area) will be retained and renovated in the project. This represents more than 95% of the building’s mass.
♣    Salvaged wood and bricks from the demolition will be re-used in the construction project.
♣    Demolition waste will be sorted and separated for re-use and re-cycling with the goal of a 75% diversion rate.
♣    Construction waste will be sorted and separated for re-use and re-cycling with the goal of a 95% diversion rate.
♣    Post construction, the reduction efforts will include purchasing decisions that reduce packaging and waste; swapping, sharing, and giving/receiving used items; recycling in the municipal program; backyard composting; and composting within the municipal program. A baseline will be established in the first year that has 80% diversion by weight, and then a plan for future improvement will be established for 95% by 2020.

Sustainable Transport - biking and walking, and car sharing when needed
♣    The location has been chosen in large part to reduce the need for a car. Most amenities are located within a 5-minute walk of the house.
♣    Walking, cycling, transit, are prioritized over vehicle trips.
♣    Carpooling, use of a car-sharing program, inter-city travel by train will also reduce single occupant vehicle trips.
♣    The average Ontario resident has 570kg CO2e emissions related to transportation, our target will be below 114kg by 2020.

Local and Sustainable Materials - FSC, local, salvaged materials and no nasties
♣    Re-use as much of the existing building as possible.
♣    Source salvaged materials for elements that have high-embodied energy (e.g., extruded polystyrene insulation).
♣    Use salvaged and FSC lumber where available; where not available use local managed woodlots.
♣    Use high- recycle content materials following LEED guidelines, including SCM’s in concrete, drywall, steel, insulation, and flooring.
♣    Source locally following LEED guidelines.
♣    Avoid items on the “red-materials list” published by the Living Building Challenge
♣    Non-toxic finishes, no added UF

Local and Sustainable Food - growing our own, buying organic and local, laying off the bacon
♣    Design the house with some growing space available
♣    Design the house with a cold cellar
♣    Design the house with a large and efficient freezer
♣    Continue with the community garden
♣    Continue with the CSA (Community Supported Agriculture)
♣    Continue a vegetarian diet
♣    Continue to buy organic products when a regional option exists (i.e. – don’t buy organic red peppers from Israel when non-organic ones are available from Niagara)

Sustainable Water - a kick-ass cistern in the basement, and water efficient appliances
♣    No potable water for sewage conveyance – cistern for harvesting enough rain water to carry through the winter
♣    No potable water for irrigation or exterior maintenance
♣    Low flow fixtures and dual flush toilets
♣    Water efficient appliances – dishwasher and clothes washer
♣    Re-use or infiltrate all rain water that falls on the site, with the exception of overflow situations to storm sewer.
♣    Reduce the impermeable surfaces on the site by 30%

Natural Habitats and Wildlife - turn gravel to habitat and love the big tree in the yard
♣    Restore the backyard from asphalt and gravel to a living surface
♣    Cull invasive species and plant native species
♣    Plant food bearing vegetation
♣    Devote some roof space for vegetation
♣    Respect the large front tree by designing a system of storm retention that allows time for infiltration. Enhance the yard around the tree and respect the root zone in the development.

Culture and Heritage - appropriate design and educate others on sustainability
♣    Retain elements of the existing house - example red brick façade, porch and open balcony concepts etc in the architectural expression.
♣    Further a cultural shift toward sustainable urbanism. Invite local schools to view the house and the efforts to achieve the 10 principles
♣    Publicize the project widely and accept tours organized through local grass-roots organizations.

Equity and Fair Trade - consider where things come from and who makes them
♣    Use a social justice screen for material choices (e.g., no PVC)
♣    FSC and salvaged wood
♣    Contractor safety record, and a culture of safety for the project leading to no accidents.
♣    Local demolition labour instead of machines.

Health and Happiness - healthy materials and a comfortable design
♣    The design of the house revolves around access to the sun and the needs of the family. It balances the need for gathering and social spaces with some dedicated specific spaces for each family member. These spaces will improve happiness:
♣    Reading nook
♣    Home office
♣    Kids' combined room
♣    Open concept living space in the middle of the house open to outdoors and street balcony
♣    Rooftop patio/garden
♣    Private back yard
♣    Health has been considered for the occupants of the house and the surrounding community, features include:
♣    Whole house water filtration
♣    LOW VOC materials – good for workers, occupants, and will not contribute to urban smog
♣   Reduced heat island effect - Green roof on shed and part of roof, highly reflective roof.
♣    Managing storm waster on site reduces the capacity issues with Ottawa’s combined sewer overflow.
♣    Beautifying the neighborhood- the current house is tired and dilapidated.
♣    Greening the small backyard that neighbours look upon will be a small natural element oasis in a sea of asphalt.

BuildGreen Dream Team

2010-06-09T16:38:00.000-07:00

BuildGreen has been very fortunate to work with design professionals from all disciplines on a variety of projects that share our values and dedication to sustainability. For the One Planet Reno, we have drawn on many of these same people – some formally, some informally to help us make the difficult design decisions required to achieve our goals. These people not only bring years of experience, but also bring a passion and enthusiasm that makes this process fun and exciting. When people of this caliber collaborate, the change we need in our world seems possible. These guys (and gal - big props to you Carolyn) are the green building equivalent of the '92 US Olympic basketball team. Carbon doesn't stand a chance when Danny Pearl is driving for energy savings, or Bill Sullivan is throwing down a nasty R-60 wall section. The following people are owed a considerable amount of recognition for their contribution to the project to date:

Albert Celli, Structural Engineer
Bill Sullivan, Building Science
Carolyn Jones, Architect
Daniel Pearl, Architect
Malcolm Isaacs, Mechanical Engineer
Simon Jones, Architect
Tobias Fellows, Architect
Tom Goddard, General Contractor
Trevor Butler, Bio-Climatic Engineer

What the Foam?

2010-06-09T14:21:00.000-07:00

As shown in an earlier post, we planned to use closed cell spray polyurethane foam (SPF) for the wall sections in the renovated part of the home. There are a variety of reasons for this – R-value per inch, air sealing properties, and moisture barrier properties. The foam we had chosen looked to be about the best on the market in terms of IAQ, recycled content, bio content etc.

There were two main drawbacks of this approach in our minds –

1-   the embodied energy in the foam and blowing agent

2-   the issue of disassembly – meaning once you foam a bunch of elements together, they can’t be separated for re-use when the house is torn down.

Weighing the pros-and cons of this, and making some assumptions about the embodied energy/ embodied carbon – lead us to justify the foam……until last week.

Daniel Bergey and John Straube recently published their findings of a life cycle analysis of the global warming potential of the foam products versus the global warming savings from the energy that is avoided from insulating. The results have been summarized and re-published here - http://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/avoiding-global-warming-impact-insulation

The short story is that if we extrapolate their data to the One Planet Reno project, it is likely to take 60-80 years of energy savings to overcome the global warming effects of the foam and blowing agent that we had planned to use. Needless to say, that is not congruent with our goals of mitigating climate change.

More discussion on this topic and its implications to follow in later posts.   Some options include using water or CO2 blown foam, reducing the amount of foam so we get the air sealing benefits that we desire, etc.   For now, we encourage you to click the link and review the research. Needless to say the new design will respond to this unfortunate reality.

Dynamic Buffer Zone

2010-04-26T06:24:00.000-07:00

Lots of discussion happening about creating a Dynamic Buffer Zone on the south side of the house. A Dynamic Buffer Zone (or DBZ for those in the biz) is basically like a sunroom or conservatory on the exterior of the house. It would be a space only heated by the sun and passively ventilated. The advantage of a DBZ is that it can help create an ultra-efficient envelope even if your contractors are not particularly diligent about detailing. We have so little contractor experience with Passive House construction techniques and a DBZ is a way to help mitigate against a lack of experience. It also can create some very wonderful indoor/outdoor spaces with plants and lots of light. For a great example of DBZ in action check out BedZED.

Our limitation using a DBZ is that the lot is very tight and Scott wants a big balcony out to the south where his family and friends can eat meals and socialize. We also don't have a lot of floorspace available to lose on the inside of the house. As a bit of a compromise we've been working on design options that use a partial DBZ. See pictures below for what that could look like. This should create an interesting nook glazed area (a place to grow citrus and winter herbs) but doesn't make the balcony too small. It does create a slightly larger envelope, but we still think it should be an overall energy benefit with solar gain in winter, and good shading in summer from the large street trees. The challenge now is making it look good from the outside.

Video from Charrette with Scott Discussing PassiveHouse

2010-04-22T06:03:00.001-07:00

Here it is...

PassiveHouse ERV

2010-04-22T06:01:00.000-07:00

Part of the beauty of a PassiveHouse is that we won’t need to have a furnace.

In order to pull this off we need our rockstar envelope (see previous post) but we'll also need to use the highest-efficiency heat-recovery ventilators available - and will probably have to import it from Europe. The best systems use counter-flow air-to-air heat exchangers, while most HRVs in North America rely on parallel-flow heat exchangers. With counter-flow, the HRV can achieve heat-recovery efficiency of over 90% . If we go for certification with the Passive House Institute – then we need an HRV that they have certified (the requirement to use Passive House certified equipment seems like a bit of a money-making racket to me but that is grist for another posting).

HRVs bring in fresh air, exchanging heat with the outgoing interior air; any moisture in either air stream is retained. ERVs exchange both heat and moisture, so that moisture levels in the house neither increase nor decrease appreciably as a result of the ventilation; this is important for applications where you want to either keep unwanted moisture out of a building or keep it in. We will study the need/desire for an ERV because of summer humidity – but in general, I think we will be going with an HRV.

Ducting will be designed to be as straight as possible and has very few trunks. Long 6 or 8 inch runs will come from a main vertical duct run in the house. Ducting has a smooth interior to minimize friction and a corrugated exterior for strength. Simple balancing components are provided in the outlet registers.

We will need -

Silencers that acoustically isolate the HRV unit from the ducting to limit noise;
Control modules;
Bathroom and kitchen hood switches that can boost the air volume temporarily.
An antifreeze-filled ground-loop to temper inlet air and prevent frost in winter in the HRV. If the HRV is running in defrost it is not as energy efficient. We are also studying the idea of earth tubes – but not sure it is right in Ottawa’s summer situation.
Small, in-line "post-heaters" to condition the ventilation air

The wood stove will provide supplementary heat (this will require a long post to make the argument I am sure), and it looks like the banks and the insurance company will want baseboard heating just in case.

Basement Issues

2010-04-22T05:54:00.000-07:00

Right now the house, like any self-respecting century home, has a dark, slightly dank, and suitably unpleasant subterranean space where the furnace and electrical panel currently sit. Originally the thought was to dig up the floor (no easy tasky in a spot with only five feet of headroom) and then add superinsulation below, and then pour a new concrete floor. While this would be effective it is also expensive. The question then came up 'why spend all that money on the slightly leaky foundation and insulating it ect when it will always be dingy space for storage?' What if instead we insulated the first floor away from the basement? Then we insulate down below the frost line on the inside of the basement - this way the basement is likely to get cold in winter – maybe minus 5 or something – but not super cold (may need some heat in their to keep the cistern from freezing, but that is another issue). Keep the operable windows in the basement to vent the space in the summer. On the outside, treat the water infiltration at the surface by sealing the connections between foundation and asphalt and re-pointing above grade. I think this proposal will see my foundation freeze above grade – where it is dry, but not freeze below grade. We can do this for a fraction of the cost.

2010-04-20T04:56:00.000-07:00

Over the past couple of weeks we've had had lots of advice on the wall and roof sections both structurally and thermally. We've started to put together some options for further discussion and some costing.

This plan gives us close to R50 walls, R90 roof, and an R30 break between the 1st floor and the basement. ( This basement situation is still to be worked out on many levels)

I think we have clarified that the interior stud wall on the new 3rd floor that is non load bearing can be wood.

We're also kicking around the idea of a recycled epdm membrane instead of the Tyvec layer on the roof – could be interesting.

I have not detailed the front and rear walls – but I believe we will build them out of wood – not steel stud, but otherwise be a similar section.

Some final notes - I have a line on some used XPS – enough to do the 6” on the roof and 6” in the basement. The tenant has agreed to move out on June 6th – so we will have a project schedule out soon.

Section options are as follows:

Pictures of the House

2010-03-09T17:37:00.000-08:00

So here's the house that was ultimately the winner - very good solar access, incredible neighbourhood where we can walk to all services and amenities, close to schools, lovely looking neighbours, and some not so bad bones to work with. You'll see from some of the pictures below that although it has some charm from the street it isn't quite in move-in condition.

What's a One Planet Community?

2010-03-09T17:28:00.000-08:00

We've been debating between using different frameworks and rating systems for this project. We do plenty of LEED work, and all of Windmill's projects to date have been LEED Platinum. We like a lot of things about LEED, and have great fondness for the good people at the Canada Green Building Council but we wanted to push the envelope even further (though we may still register under LEED for Homes - that debate to follow). We also quite like the PassivHaus approach and will be shooting to meet PassivHaus standards (much more to come on that), but PassivHaus is really an energy standard and we all know sustainability is much broader than that.
Our preferred framework to date has been One Planet Communities, developed by the innovative and entrepreneurial UK based ENGO called BioRegional (www.bioregional.com). Over the past four years we have been enlisted as senior technical consultants for a small handful of proposed One Planet Communities in California, Alberta, Washington DC and Montreal. The framework is based upon 10 Principles (check out the principles here - .http://www.oneplanetcommunities.org/technical/index.html). The Principles are clear, ambitious, based upon ecological footprint methodology, and pretty much cover the gamut of sustainability principles we think are important.
Normally One Planet Communities limits themselves to working with developments larger than 1000 homes. Lots of good reasons to work on this scale - allows for true mixed-use communities, generates great publicity, allows for innovate energy solutions and so on. However some recent work on One Planet Suburbs, and a recognition that we need to deal with the building stock we already have if we are going to achieve true sustainability, has led them to at least consider including our project in the fold as a pilot. We've been having the discussions with BioRegional and BioRegional North America and hope to know shortly whether we'll be able to have some kind of formalized arrangement with One Planet Communities, and the participation of BioRegional North America's Executive Director Greg Searle.

The Location

2010-03-09T17:17:00.000-08:00

Our first consideration in creating a deep green house was to find a location that facilitated sustainable transportation modes (like walking, biking, taking the bus), had great solar exposure and kept Scott's young family away from major highways (the California Air Resources Board released a report recently saying that living along highways can shorten life spans by 10 years!). The other two main criteria were that it needed to be affordable and available. It looks like a short wish-list, but that short list eliminates over 90% of Ottawa.

We narrowed our search to a few neighbourhoods that would allow us to walk for most of our needs, have good connections to transit, and generally works for our young kids. This means relatively close to school, at least 5 blocks away from the 8-lane highway that cuts through most of the great old Ottawa neighbourhoods, and has good access to open greenspace. Our short list were are all older, established neighbourhoods where lots in our price range are sure to be narrow – 33 feet or smaller.

The challenge with all of these neighbourhoods is access to the sun. The typical street grid in Ottawa is rotated 30 degrees east of south. This grid works nicely to allow most city lots to enjoy sun from a variety of angles. However, in a passive solar design, you really want the maximum exposure to true south – or at least within about 15 degrees of south, where you have the best chance of controlling when and how much sun is invited indoors.

Given the angle of the grid, size of the trees, width of lot, and the height of the houses in most of these neighbourhoods, most lots on the south side of streets simply don’t get enough sun. Or, if they do presently, there is little preventing a read yard neigbour from building higher, or trees from growing taller. Therefore, most lots and houses on the south side were not good candidates.

Houses on the west side of the road in these neighbourhoods were also eliminated. They are typically shaded from the back yard by dwellings and trees, and the street face only gets sun early in the morning.

This leaves houses on the north side and east side of the road. Ideal solar access would be a corner lot on the northeast corner. Second best would be a northwest corner. Corner lots come on the market very rarely, and in the neighbourhoods were interested in, they are often small lots – 25X50 or 33X66 are not uncommon. The city required setbacks from the road on these lots is larger to ensure safe sight lines around corners. The result is that the footprint of any house on these lots is very small. When a larger lot exists on a corner like this – infill developers scoop them up very quickly for multi-unit projects. So – while a corner lot would be ideal for solar, we struggled to find any.

Our original hope was to find an infill lot that could be or had been severed from a larger property. These are rare, and despite testing our several against our concept, we could not find one that could work.

It was like Goldilocks - too big and those rapacious developer types were all over it paying far more than we were willing to spend, too little and it just wouldn't be possible to fit the house Scott wanted for his family.

The next idea was to buy a “tear down”. Several of the neighbourhoods we like have the odd property that have little salvage value relative to the value of the land it sits on. We considered several of these on larger lots, with the hope that we could build a semi-detached house in place of the single we remove. However, there are many infill developers in town who are doing that exact thing, and this has driven he price of these properties out of reach for my family. In fact, we had one case where a lot in Old Ottawa East went for $168,000 over the asking price of $500,000.

After several unsuccessful months of looking at infills and tear-downs, we started considering a major renovation as an option. The advantage is that there were more options on the market. The disadvantage is that it puts many more constraints on the design, and given the scope of our vision, it pretty much eliminated the idea of a semi-detached. Keep posted for what we found...

An Introduction

2010-03-09T17:04:00.000-08:00

First off an introduction - we're the team from BuildGreen Solutions (www.build-green.com). We're a small boutique firm of green building/green community experts. Our parent company, Windmill Developments (www.windmilldevelopments.com) has been responsible for developing some of the greenest projects in the world. We help by doing development management (that entails all elements of getting these projects built), facilitating the integrated design process, and through sustainability consulting. To help spread our message that deep green can also be economically rewarding we also do education work and a smorgasboard of development management and sustainability consulting for enlightened clients.
While most of our projects have been large mixed-use developments our latest project is a little more personal. Scott Demark, a BuildGreen partner, is embarking on creating a very deep green home for his family. This blog will follow the progress as we turn a tired 1920's home in a great urban neighborhood into a One Planet Communities pilot project. We're exploring using the PassivHaus Planning Package Software and LEED for Homes. We'll be going net zero energy and capturing rainwater to put in very water efficient toilets; we'll be looking at earth tubes and reclaimed wood, zero VOC paints and ultra-efficient wood stoves. Design is just about to begin and we're aiming to update the blog once a week. Stay tuned....