Sunday, October 3, 2010

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

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

Wednesday, September 8, 2010

Healthy Enough to Live In

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.

Wednesday, August 25, 2010

Unvented Roof Space/Evening Fun with the Building Code

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.

Tuesday, August 24, 2010

Wonderful World of Windows

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 fa├žade, 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.

Thursday, August 19, 2010

Warning: Do not drink this post...

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...

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:
  1. A challenge to the use of hose bibs with our rainwater harvesting system;
  2. Concern about our non-standard insulation/non-venting for the flat roof;
  3. 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
  4. Disagreement about zoning interpretations.
We’ll blog about each of these as they come to resolution with plenty more detail to follow.

Monday, August 9, 2010

Love Your Neighbourhood Forest

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.




Sunday, August 8, 2010

Demolition Time

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.


  1. plaster, drywall, old paneling all has lead paint so we could not do anything with it – more layers = more landfill.
  2. The back room is now going to be removed by a backhoe because there is nothing salvageable and it is not stable.
  3. Some of the wood we planned to salvage is mouldy and or soaked with urine – so it adds to the landfill pile.
  4. 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.



Friday, July 30, 2010

These aren't too shabby either...

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!

Tuesday, July 20, 2010

Now For Something Controversial

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.