Viewpoint | Occasional opinion from SABMag readers
What price the old paradigms?
by Robert Malczyk
Retrofitting urban areas to be greener is one of the most important aspects of sustainable development - but our cities have been designed to an earlier paradigm and dismantling the legislation that created and perpetuates them will be quite a trick.
Vancouver may want to be the greenest city in North America, yet my own recent experience trying to push the green envelope of residential development has left me disillusioned - and a lot poorer than I would have been had I taken the conventional route.
Architect Oscar Flechas and I first submitted an application to the City of Vancouver three years ago proposing to build a new energy efficient house to a standard many times better than a typical Canadian home. To achieve this level of performance, the massing needed to be simple, the windows sized and oriented for maximum solar gain, and the envelope super-insulated - all of which seemed in keeping with the City’s own environmental goals.
Accordingly we proposed the demolition of the existing 1906 structure [built to now obsolete standards, much modified and of no structural value] and its replacement with a new, simple modern structure. The City refused this application and informed us that we must renovate the existing structure, and restore the building to one of several heritage styles identified in the Kitsilano Design Guidelines.
We chose the style most suited to our energy efficiency goals, and resubmitted the drawings. This proposal was also rejected and we were told that the aim of the renovation must be to mimic the house next door, of which ours had once apparently been a mirror image. We were directed to retain the first 12 feet of the building, and to lower and move the house which had been raised in the 1980s.
We wanted to use 2×6 construction to achieve basic levels of insulation - and in addition install a rainscreen cladding system concealing another 2in. of exterior insulation. This meant we had to design the new 2×6 structure, carefully placing the new studs between the old 2×4s we were required to retain. Among the submission requirements was a colour coded plan showing the new construction and the existing structure to be retained. It is worth pointing out that this existing structure was not only redundant, but became completely concealed in the new walls - serving no purpose other than creating unwanted thermal bridges.
Windows were an issue too. We wanted lots on the south [street] façade for passive solar gain, but because the project was now deemed to be a renovation, we were required to replicate exactly the size and multi-pane configuration of the existing windows. Of course, the thermal performance of windows is poorest at the frame, so being required to fabricate and install multiple small frames instead of one large one was not only much more expensive, but resulted in poorer energy performance.
For durability, we wanted to use wood frames encased in aluminum - wood visible inside the house, black anodized aluminum on the exterior - but this was not acceptable either. The city required a wood finish on the exterior as well - although they had no problem with us painting it black! After considerable research and additional expense, we found a supplier who could encase high-performance, triple-pane wood windows in an additional “sacrificial” layer of wood that could be periodically replaced independently of the frame.
We also encountered another problem in the zoning regulations which use setback lines and height restrictions to define the envelope within which the permitted FSR could be built. Depending on climate, a high-performance house may have walls up to 16in. thick and, if constructed within the zoning envelope, this may make it impossible to achieve the permitted FSR. Given our current method of calculating value based on floor area, this system can result in a house that is worth less even though it costs more and performs better. [Partly as a result of our project, the City of Vancouver has begun a review process to examine and address this issue.]
After three years, and tens of thousands of extra dollars, our house is complete. Its energy performance is four or five times better than a standard new house, but much less efficient than it might have been had the City been less concerned with empty “facadism”, and more attuned to the broader goals of sustainability.
As a footnote, the City of Vancouver has since published its Passive House Design Kit for Homes - a document advocating an approach to design that in the case of our project was resisted every step of the way. Only time will tell if this is substantive policy change, or just more smoke and mirrors.
Robert Malczyk is a Vancouver-based structural engineer and partner in Equilibrium consulting Inc.
