Green building retro fits?

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Permalink Reply by Randy Chatterjee on February 11, 2012 at 10:01pm

Stephanie,

Taking as a given that the greenest building is almost always one that already stands, I applaud your focus on retrofitting.  It is really the only climate- and economically responsible thing to do.

However, given our mild climate with average annual temperatures in the Lower Mainland at circa 14C, an annual temperature standard deviation of about 4, and little if any air conditioning, our focus on building energy efficiency is practically non-existent and excused almost entirely for economic (aka financial) reasons.  Of course, the City of Glass also sells itself through its views so floor-to-ceiling glass fenestration with an effective envelope R-value of 2 or less is in fact driving our average city-wide building efficiency steadily lower every year.  (Even the older 1950s apartment building stock--with no energy retrofit--has effective R values between 2 and 4 times greater than the newest glass towers.)

So, we are trapped by the combined inefficiency of our older stock and the even worse performance of the new.  I would note that high-rise glass, steel, and concrete towers also have high energy requirements for air handling and elevators, and present enormous carbon footprints just in construction.  They fail every climate-friendly test.

So, in comparison, the older buildings are hardly bad at all.

But I am now being facetious.  Just because there is something worse happening is no excuse not to fix or improve what you can.  

But then try to understand that the now historically high rents render utility bills, specifically for space heating, a minor nuisance, rarely higher than 20% of the rental payment in the coldest month, and closer to 10% on an annual basis.  Those with electric heat may also take the position, and I know many who do, that "carbon-free" Hydro power absolves them of any climate guilt for their inefficient building envelope.  

But let's still consider solutions, at least for the morally pure.

Window quilts are a wonderful and highly-effective solution, offering easily a tripling of the efficiency of a window. An older R1.2 or super-modern triple-pane R3 window can be boosted to R-6 or even R-8.  Depending on how tightly a quilt seals to the window frame, it also limits air infiltration and thus draftiness in a room.  So in short, this is a great solution.  

However, even if custom-built solutions existed, or were available in sizes every 2-3 inches, they are not trivial to mount and seal and are extremely unlikely to be easily removable by a renter in order to bring to another apartment.  Window sizes are just too varied, both in width and height.  Furthermore, if you just bought a pricey condo with views to the North Shore mountains, you are highly unlikely to want to block your view at any time.

Be careful with Styrene (aka Styrofoam™) for obvious environmental reasons. Also, given the enormous problems here with mould growth, adding another vapor barrier to a wall system--especially mating it with additional insulation--can be very risky.  The paint may be the only other one vapor barrier (albeit imperfect), but impermeable membranes have been used in Vancouver throughout building envelopes for decades.  So, trapped and cold moisture is a sure bet.  A better, albeit ugly solution might be Radiantec, mylar bubblewrap with a silver radiant-reflective coating.  Still, the problem of mould remains.  

Another potential solution is new insulation added to the exterior cladding.  Many buildings in Europe have their envelopes tightened up from the outside.  If buildings have envelope problems already--most every building in Vancouver--then a high-efficiency applied insulation layer of several inches on the exterior, in place of or over the existing exterior finish can offer huge energy-saving advantages.  

Overall, I would focus just on the windows as the biggest bang for the buck.  However, one should be careful of moisture build-up also on the windows, especially if they are wood.  They will not last long and mould can also be a persistent problem.

As for mounting such window quilts, I suggest white velcro loop tape on the walls, It can be left in place all the time, and even between renters, and provides a reasonably tight seal.  Sliding tracks are also used, but few standards exist to enable a quilt to be replaced or a new one added by a new renter.

Another area for improved efficiency is the heating unit itself.  Whether gas or electric, the technologies for both have vastly improved efficiencies in the past 10 years.  Vancouver has a large stock of the most inefficient heating sources I have every seen, sporting ratings of 40-60%, when newer heat-pump or internal gas systems have efficiencies in excess of 95%.  Since this is a one-time central retrofit with a clearly-definable payback, its economic value is measurable and positive.

But of course landlords not paying the heating bill might not care...but could be induced to take action.  

Why not institute an energy rating requirement for all housing units, a dwelling Energuide number?  This would provide full transparency of the heating costs to prospective tenants.  In a renter's market and with higher energy prices (coming soon), there will be a flight to more efficient apartments given equal rental rates.  Then apartment owners would be incented to act....at least if they owned the entire building.

So, of course rented strata units would escape such incentives.  There are a huge number of these, and they will likely increase dramatically. 

Please note finally that the rental market is already oversaturated with supply--just check Craigslist--but rents are sticky or rising because the holding cost of newer stock is so high that owners cannot sometimes afford to drop rental rates.  I expect what little profit exists in the current rental market to disappear entirely.

So, for your thesis, consider replacement heater units first, then window quilts (or other retrofits) and then new wall treatments, in that order. 

Also, you will be hugely benefited by calling Embers home renovation research team.  Talk to David Pryor at 604.692.0781, and tell him I sent you his way.  He is a true expert on this issue.  A recent presentation he gave to Village Vancouver is here.

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Permalink Reply by Paul Pilon on July 29, 2014 at 9:48am

Direct drive washing machines use 1/10 the power of conventional units and are in the same price range.

Any house could (and should) have a few solar panels and be grid tied and that pays for itself in few years.

Rain water collection for yard irrigation.

Power bars.

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