BUILDINGS: On the trail of the green pioneers
By the 1990s the environmental movement in Canada was gaining steam and Canada started to see a few adventurous designs for "green" buildings. They were very odd buildings in many ways. They had stran...
By the 1990s the environmental movement in Canada was gaining steam and Canada started to see a few adventurous designs for “green” buildings. They were very odd buildings in many ways. They had strange shapes to encourage air currents for natural ventilation, used old timbers and other recycled materials. Some were decked with sod roofs or rigged with strange contraptions like solar panels and rainwater cisterns.
Traditional mechanical and electrical engineers were sceptical. They muttered about “tree huggers” and laughed at drawings of buildings with “pretty arrows” showing natural ventilation. They felt that the green building designers were naive. Few believed that natural systems in a building would ever be enough to satisfy North Americans who expect a constant 70 degree indoor temperature. Business people want to be comfortable indoors dressed in a suit, no matter whether the building stands below a blazing desert sun or in the ice fields of the Far North.
The green building designers continue to preach to the choir at environmental conferences, while the mainstream engineers stay away. The latter, often working for large, corporate clients, choose to concentrate on energy efficiency, partly because it shows an immediate payback. They specify automated building controls to carefully calibrate energy consumption, have stopped using ozone-depleting CFCs for cooling, and sometimes have ventured into co-generation. But their environmental stewardship has stuck there. The buildings where sustainability dictates every design decision remain few and far between — they are a small vanguard in a movement that has failed to gain ground.
Are the traditional engineers right in expecting that the more radical green buildings will turn out to be white elephants? Do these idiosyncratic buildings end up as misguided experiments?
Not so, judging by a handful of model environmental projects completed about five or six years ago. For the most part, the owners and occupants of the buildings described below are happy with their performance and very comfortable in their environments. The picture isn’t perfect, but then even conventional buildings have their teething problems. Despite the sceptics, the green pioneer projects are proving to be sturdy creatures.
C.K. Choi Institute for Asian Research
The C.K. Choi building in Vancouver is still held up as possibly Western Canada’s finest example of green building. Constructed in 1996, it was built using about 50% recycled or reclaimed materials such as old timbers. It has composting toilets and an on-site wastewater treatment system that releases grey water into a wetland. Matsuzaki Wright Architects led the design team that included Keen Engineering (mechanical), Robert Freundlich (electrical) and Read Jones Christoffersen (structural) as consulting engineers. By all accounts it was a synergistic design process.
Like other buildings on the University of British Columbia campus, C.K. Choi does not have air-conditioning. For cooling it relies on 100% natural air using the stack effect. Five atria with sweeping roofs run along the spine of the linear structure. Air enters through fixed air-grilles below operable windows at the lower level. It then rises naturally up through the atria spaces to be exhausted using huge fans through louvers at the top. The system provides 20 cfm outdoor air per person.
The university has monitored C.K. Choi’s energy use. Measured against a comparable building also without mechanical cooling designed according to the ASHRAE 90.1 energy standard, C.K. Choi is saving 23% energy overall (heat and electricity combined). This performance does not meet the 35% design target, but it is still good.
Most of the energy savings at C.K. Choi are in the electricity used for lighting, hot water heat, computer power, etc. Consumption is 69% below the ASHRAE 90.1 model building. With ample daylighting from large window areas, combined with sensors and continuous dimming ballasts, the lighting power density is only 0.7 watts per square metre. This figure compares to a norm of 12-18 watts per square metre.
Space heat is supplied from the university steam plant through a heat exchanger into base heaters. It is here that C.K. Choi pays the energy price for its high ventilation and indoor air quality. The building uses 69% more heat energy than the ASHRAE 90.1 model. In its building review, the university blames the continual air flow and the structure’s high window-to-wall ratio for the heat demand.
All has not been smooth sailing with the exhaust fans. According to Freda Pagani, director of sustainability in land and building services at the university, the fans were supposed to operate during night hours, but there was a problem programming their set points with the building management system, and as a result they kept coming on during the day — much to the annoyance of the graduate students. “The noise was like an airplane,” says Pagani. “Every time the fans came on it enraged the users.” The engineers have managed to adjust the settings now, but it took about a year to get it right.
Conservation Housing Co-op, Ottawa
In 1995 the designers of the Conservation Co-op residential building in downtown Ottawa also set out to build a model green building, this time for private clients who were not only environmentally conscious, but cost-conscious as well. As Duncan Hill of Canada Mortgage & Housing Corporation recalls, the Co-op’s motto was to build: “something that won’t cost the earth.” Packing 84 units into an L-shaped, four-storey building, the project designers (Cole & Associates, Glendon Evans, Graham Murfitt, Ashton Engineers, Leslie-Jones & Associates) tried to roll in as many environmentally conscious features as possible. The cost was $654 per square metre.
They designed a highly insulated and efficient thermal envelope, R26 value walls with low-e windows and an R20 roof. They took pains to reduce thermal bridging by using rigid insulation on the outside of the walls and constructing balconies that are structurally independent. Each apartment has its own high-efficiency, sealed-combustion, gas-fired condensing hot water tank, which also provides baseboard space heating.
Hill was in charge of a CMHC research project in which they went back to the apartment complex after five years to do a performance review. CMHC had not financed the building, but it had provided funds for a pilot grey water recovery system.
“Overall,” Hill says, “given the clients’ goals, the building was rather successful. You can look at this in straight hard numbers in terms of energy and water performance, through to the softer issues of the success of recycling and the use of gardening facilities.” He points out that the Co-op did many important things like foregoing the requirement for parking spaces (it only has eight) to encourage residents to use public transit. The Co-op also has new owners sign a green policy that requires them to do things like sort out the communal recycling, and to agree not to install window air-conditioners.
The CMHC reviewers found that the building uses 51% less natural gas than a comparable equivalent residential building constructed according to the building code in 1995. However, they also found that it uses 28% more electricity. Overall, combining energy from natural gas and electricity, it uses 22% less power than a comparable building.
Why was the electricity use so high? As with the C.K. Choi Building, the researchers believe the problem relates to the high ventilation rates.
The owners decided to have continuous ventilation for every apartment using heat recovery ventilators (HRVs) on the roof. “It [the system] works fine as a ventilator,” Hill says. “The problem is a lot of fan motor energy consumption. There is a fan coil in every apartment running continuously — and there are 84 apartments, and 21 HRV’s up on the roof, with two motors in them running continuously.”
The CMHC is working with the Co-op to find alternative cooling strategies for the building. The passive methods of keeping existing shade trees
, having balconies provide shade and low-e windows to block solar gain are not enough, and Hill points out that “people do suffer.” He says it is very difficult to cool multi-unit residential buildings with passive methods in cities like Ottawa and Toronto that have “swamp-like” environments. By their nature apartment buildings are compartmentalized, so it is difficult to create large natural air currents.
The grey water reclamation system installed to serve eight of the Co-op Units has been unhooked. Hill says while it was working “the numbers were right” in terms of saving water, but whenever the maintenance staff met a problem, they switched to the parallel municipal system. As a result the grey water system tended to silt up.
Kitchener-Waterloo YMCA Environmental Learning Centre
At the Kitchener-Waterloo YMCA Environmental Learning Centre near Paradise Lake, director Callum McKee has been living with its various green building technologies for six years. When asked whether the building has lived up to its promise, he quickly replies “very much so.”
Designed by a team of Charles Simon Architect with Allen Associates, the centre is a demonstration green project in all its facets, including having an on-site “living machine” biological sewage treatment and grey water recycling system that McKee says is a thriving success.
The complex has a day centre with meeting rooms and a solarium containing the biological water treatment plant. There is also a residence building for about 35 people, which is completely off the electricity grid. Recently the centre added more cabins built with strawbale walls. McKee says the centre is so popular it is fully booked for a year.
The two main buildings are half-buried in the earth and have sod roofs, which gives them good natural insulation. McKee says that during the winter they will maintain themselves at 12C without any heat input. Passive solar heat gain in a solarium in the day centre is captured and sent through vents in the floor slabs.
Originally, there was supposed to be a cooling system using collected rainwater that was to run down the sloped window of the solarium. “To be honest we’ve never used it,” says McKee, “We’ve never had the need to.” He says the low-e, argon-filled windows prevent too much heat gain and the natural ventilation gives adequate cooling. The buildings are cut in strange profiles to encourage the stack effect, with operable windows at the bottom and at the top. McKee enthusiastically endorses the approach. “It’s like having a full-fledged high power fan on,” he says, “The stack effect is enormous.” Charles Simon, the architect, however, says the natural ventilation in the residence has some problems during the shoulder seasons (spring and fall) and when the wind is blowing in a certain direction.
Each building uses only 2 kW a day for electrical power, McCallum says, which compares to about 12 kW a day for an average house (heating is by high-efficiency wood stoves). In the residence, 80% of the power comes from wind, and 20% from solar sources. The ratio is reversed in the summer.
The wind generator has surpassed expectations. In fact the windmill was turning so fast they had to change the 600-watt generator for a more robust 900 watt unit. The photovoltaic array hasn’t been as productive, but it is still satisfactory. “Solar is O.K.,” says McKee, but “If you wanted me to rate it I’d say about a 6 out of 10, just because it’s still a finicky job getting things to be powered correctly.”
McKee’s delight in the place is clear. As he talks, he admires the view of the countryside visible through the wide windows. Indeed, the most successful aspect of all these green projects is difficult to measure in statistics because it comes more from the sense of tranquillity they give to users who are made to feel in harmony with nature — the daylight, the natural air, the relative quiet. All the people interviewed said — without prompting — that their buildings were lovely places to be in.
Healthy House, Toronto
Rolf Poloheimo is the owner and developer of one of the most adventurous green projects of the last decade. The CMHC Healthy House in east Toronto was opened with much hoopla in 1996 as a demonstration home that could be completely independent of the municipal water and power supplies. The original design by architect Martin Liefhebber with Allen Associates won a national competition and was only 850 square feet. The built version consists of two semi-detached houses, 1,700 square feet each, located in Riverdale.
Poloheimo is still living and working in one of the homes, and he now runs a business selling the grey water recovery systems installed in his house. The systems were developed at the University of Waterloo.
The adjacent house was recently purchased by the tenants who lived there for several years. Their willingness to buy the house is the best possible reference for its liveability.
Poloheimo is delighted with his own home’s passive solar performance: “It’s the most comfortable house I’ve ever lived in, he says.” No-one has formally monitored the actual energy savings, but he says their electricity bills are low — about $600-$700 a year. Of this amount he tabs $200 for the back-up hydronic floor heating.
The built homes are not off-grid as was proposed, but they are grid-interactive. When the photovoltaic panels arrayed on the south facade produce more power than the house needs, the hydro meter goes backwards and gives a credit. Poloheimo says an inverter blew up, but this was an early teething problem and the utility replaced the unit.
The on-site sewage treatment and grey water recovery systems are working well. The recycled, treated water is used for washing, toilets, etc. Potable water comes from rainwater collected on the roof and is treated by ozone. A few years ago there was a leak in the 17,000 litre cistern, but after it was fixed Poloheimo maintains they have “tons” of water. Last summer, in the worst drought they have experienced, he says they still had one-third of a tank.
More monitoring needed
Overall, then, the buildings revisited for this article suggest that green design is nowhere near the gamble it is often portrayed. The examples were chosen randomly from several that were published in the trade press five or six years ago. And although there are at least two other green projects not reviewed that have gone into litigation, legal disputes are not unusual for any construction project. In one case the problem was a small item of equipment and the case was resolved in favour of the engineer.
What is surprising is how little formal post-occupancy monitoring of green buildings is being done. Much effort and sometimes public funding goes into the design of green buildings during the concept and design stages, but there seems to be little formal effort to examine how well the green solutions actually worked. As one architect said, “I like to know what works and what doesn’t so that I don’t make the same mistakes again.”
If the engineers and designers who advocate green building want to be taken more seriously by the mainstream construction industry — which is notoriously conservative and traditional — then having hard facts, figures and references at their fingertips about how well their projects are performing will be like gold. Without that evidence, the “tree-huggers” will remain out on the fringes of the forest, watching despondently as the building industry continues to do things in the old ways.
Engineer Greg Allen, who has been a driving force behind many of the greenest projects in the Toronto area and was involved in two of the projects reviewed, says he is tired of trying to lead clients and other engineers away from the “conveyor belt” approach to design. He’s heard too many mechanical engineers take the approach of telling clients, “Just give us the drawings and we’ll show the ducts up in the roof.”
Still, he remains committed to taking a radical approach to environmental design: “I’m in it for life,” he says. “My children, the world, will hold me to account, so psychically I haven’t got a