by Guy Dauncey
It’s only twenty years ahead, but innovation in the building industry is happening faster than in any previous era, driven by concerns about climate change and a desire to end our dependency on ancient fossil fuels.
Do we really have to drill deep into the Gulf of Florida and the Arctic or tear up a chunk of Alberta’s boreal forest to get the energy we need? Many people hope not, and when it comes to our buildings this is driving a wave of innovation that will change everything. So come with me on a visit to the future.
It is 2032, and we are driving out in our smart electric vehicle with its 1,000 kilometre range to visit a new 250- unit development.The project has been planned using the province’s Smart Growth Code as a pedestrian-oriented community with a village commercial centre that includes a cluster of three-storey affordable townhouses, a children’s play area, a bus shelter and a coffee shop with outdoor seating where people like to gather.
The roads weave their way between landscaped ponds, open creeks, trees and shrubs without any separation for sidewalks or bicycle paths, so the cars are naturally constrained to drive at a slow speed. As well as housing humans, the site has been designed as a habitat enrichment zone for nature, with 100% stormwater retention, native plants, and plenty of opportunities to grow food.
The project as a whole is net-zero-energy, and the passive-solar Energuide-100 green-certified homes use carbon-absorbing eco-cement in the floors of south-facing rooms to store the sun’s heat. They have been built with advanced framing techniques using six inch studs on two foot centres to save wood and avoid thermal bridges, and R-60 vacuum or foam-insulated wall-panels.
The windows are R-10 triple glazed xenon-filled on a fiberglass frame, and as well as being solar-coated to generate energy they are able both to rebuff the summer heat and open for fresh air when their occupants want it.
These technologies combine with heat-recovery ventilators to give the homes plenty of clean fresh air and an air-tightness of under one air-change per hour, using foamed in-place insulation.
For electricity, each home has a grid-attached 4 kW solar system on the roof, adding $12,000 to the price at $3 per installed watt, compared to $6-8 today. The panels generate 4,800 kWh a year, and at the 2032 price of 20 cents/kWh for electricity they save the occupants $960 a year compared to older, non-solar homes.
4,800 kWh a year is more than the occupants need, thanks to the organic LED lighting, translucent wall panels, super-efficient appliances, heat-pump-enhanced solar hot water evacuated tubes, cold storage food closets, wired in-house energy monitoring and multi-appliance switchoff sockets. Taken together, these reduce the demand to five kWh a day, plus 1,500 kWh a year for home-charging the electric car, which does six kilometres per kWh. The 1,500 kWh surplus is sold back to the grid, earning the occupants $300 a year.
These super-tight and super-insulated homes do not need additional heat. Elsewhere, new developments are using district groundsource with radiant hydronic heating, while others are using stored solar heat similar to the Drake Landing solar subdivision in Okotoks. All of the houses have rainwater capture cisterns and dual-plumbing for flushing and irrigation.
Some houses have been built using cob and straw-bale techniques with composting toilets and grey-water systems, all of which have been normalized into the building The Heliotrope in Freiburg, Germany was the first building in the world to create more energy than it uses. As well as a built-in recycling centre, each home has a self-turning composting system for organic wastes. For paints and finishes, the required standard is zero VOC, to eliminate off-gassing.
Retrofitting the City
In the city, the largest construction project in provincial history is underway to upgrade the entire building stock. By 2050, at an average $50,000 per upgrade, it will be a multi-billion dollar project, with every building being retrofitted with super-insulation and super-windows. A typical home retrofit reduces energy-use by 50%, saving $2,500 a year in energy bills. The subsidized, tax-exempt investments are repaid through building energy accounts that remain with the building at the time of sale.
Many high-rise apartments and commercial spaces are being hooked into district heating systems and reskinned with new exo-skeletons, adding 12 inches of insulation to create an airtight shell. Many city building owners are installing living walls covered with greenery that cools the air and refreshes the city dwellers. New cooling systems are being created using ponds, pools and inflow cooling towers to capture passing breezes. For new buildings, the use of timber has been approved for buildings up to six stories high. On the skyline, many flat rooftops are being converted into greenhouse garden apartments.
To meet the still pressing need for affordable housing, small single-storey 800 sq. ft. houses are being approved for d-i-y completion and easy raising at a later date into two-storey buildings. Solar roof conversions have become ubiquitous, the cost being self-financed through the home energy accounts. When a building is due to come down, demolition has given way to deconstruction, the materials being listed on region-wide websites that enable rapid auctioning.
The building industry is thriving, generating a huge number of new jobs, and enjoying innovations such as the revolving solar house. And fossil fuels? None needed. Welcome to the year 2032.
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Guy Dauncey is Executive Director of the BC Sustainable Energy Association (www.bcsea.org), and author of nine books, including the award-winning book The Climate Challenge: 101 Solutions to Global Warming. His website is www.earthfuture.com.
For More Information:
Drake Landing Solar Subdvision: www.dlsc.ca
Rotating Solar House: techcrunch.com/2010/08/20/rotating-solar-house-generates-five-times-the-energy-itconsumes/
[From WS March/April issue, 2012]
