Canadian Consulting Engineer

Green building checkup

"We were designing green buildings, we were all promoting green buildings ... but no-one was going back to double-check," explains Craig Shishido. "Did these buildings actually perform to what their d...

December 1, 2006   By Michael Eddenden

“We were designing green buildings, we were all promoting green buildings … but no-one was going back to double-check,” explains Craig Shishido. “Did these buildings actually perform to what their design expectations were?

“So we thought, as far as educating everybody on what designing green is, we need to be putting something back into the system that feeds back to the designers. We were saying, yes, these are great ideas … but maybe if we tweaked this, or did that it would be even better. That was the intent: to create a feedback loop.”

Shishido is an advisor for the Greater Vancouver Regional District who worked with a team from Keen Engineering — now Stantec — and Green Buildings B.C. to pilot a review of six “green” buildings. The plan was to see how well the buildings were performing and how well the occupants liked them.

“Rosie [Hyde] had this idea in her head and started developing a protocol,” says Shishido, explaining how they began. “We sat down and talked about what was important. Certainly, we were to look at the initial design intent of the building. It was designed green, it had all these green features, but what were those features meant to do? One was to reduce energy use. One would be to reduce water use. One would be to provide a more comfortable and inviting work atmosphere … those kinds of things.”

Having a team go into a building after it has been occupied for four or five years to rate its performance seems like an obviously good idea. However, such comparisons are rarely done in any methodical way. It is even more extraordinary for such an evaluation to be done by someone other than the designers and building owners themselves.

But that’s exactly what happened in 2003-2004 when Shishido and Hyde’s team piloted the program of “post-occupancy evaluations” of five green buildings. The buildings had all been completed since 2000 in the Lower Mainland of B.C. Jennifer Sanguinetti, P.Eng. was the principal in charge at Stantec.

Shishido explains that the evaluation was done in two parts: “One was looking at utilities … [comparing] the design intent and the actual performance of the building. The second part was to look at the occupants’ satisfaction with the building. How people perceived their work place. Is it more comfortable? Is it a brighter atmosphere to work in? Is it a more productive atmosphere? Did you find it more comfortable thermally? Were they educated and trained — occupants and operators — in what the building was supposed to do?”

Since the initial pilot study of five buildings, the post-occupancy evaluation program has morphed into further stages. It is now being run under the auspices of the EcoSmart Foundation, a federal non-profit corporation based in Vancouver. Hyde and a team of other environmental experts refined and expanded the protocol (see sidebar), and last year EcoSmart used that protocol to review a further six buildings. It held public forums to discuss the results of the reviews and is due to post reports on its web site. Ultimately Hyde would like to see the protocol used on conventional as well as green buildings, thereby creating a level field for comparison.

Less energy use, but acoustic problems

For consultants who are breaking ground in the world of green building design, having their buildings subjected to such a public evaluation could be a daunting prospect. These engineers are using technologies that are unconventional and relatively untried. At the same time, the owners and occupants of a green building are likely to have exceptionally high expectations.

And for the proponents of green buildings like Dr. Hyde the stakes are high. If the evaluations were to show green buildings badly under-performing, the results could seriously hamper the movement to make sustainable design mainstream. The evaluation program might end up doing more harm than good.

Happily such fears proved unfounded in the 2004 pilot study. The buildings included a city hall, colleges and offices. While they did not all meet their modelled energy savings, they were all using less energy than comparative standard buildings in B.C. The range was 12%-55% less energy used. Dr. Hyde was pleased: “Our big finding that we were very happy about was that the operating costs of all five buildings, including both maintenance and utility costs, are lower than conventional buildings of the same type.”

The reason the buildings fell short of the projected energy savings, Hyde suggests, is due to shortcomings in the modelling programs used in the building design. All five were CBIP buildings (designed to meet the federal government’s Commercial Building Incentive Program criteria), which meant they were modelled using a program that does not take into account different process loads. The computer models didn’t account for a building with an extraordinary number of computers, for example, nor for the power drawn by elevators, says Hyde. The models also didn’t account for variable operating schedules. So, while a building may be modelled to have systems working full tilt for 10 working hours a day, the building might have employees coming in at odd times, which means operators run the systems on high for an extra four or five hours a day.

From the occupant satisfaction side of the 2004 study, the buildings were shown to perform well in terms of their lighting and indoor air quality.1 However, their satisfaction with the heating and cooling conditions was not consistent across the five buildings. The occupants also commonly complained about the buildings’ acoustics.

As Shishido explains: “Overall the results came back positive. But what it [the evaluation process] did highlight, whether it was a green building or not, is that we’re not doing a good enough job on thermal comfort and acoustics.”

He explains the design dilemma behind the noise problem. “When it comes to indoor air quality you want low emitting materials, which means you have a lot of hard surfaces. Then acoustics become a problem.”

Green buildings also tend to have many open areas and use natural ventilation. As a result, sound carries and is not masked by the white noise of mechanical equipment.

Shishido says the intent of the building evaluations was not to discover what particular technologies or approaches didn’t work. The scope of the survey was more general. “We didn’t look at it [as an exercise] to try and find fault. We wanted it strictly to be a survey of design intent versus actual performance, and then occupant satisfaction.”

Does it mean more risk?

Inherently, though, any building evaluation is going to identify specific problems, which is where things might get dicey. If the third party evaluators find some system is not running up to par, for example, there’s a risk the owners might blame the engineers and use the report as evidence in a lawsuit.

Peter Needra, vice president and general manager at XL Insurance Design Professional in Toronto, sounds a warning. He agrees that on the surface building audits sound like a good idea. But with building evaluations he has concerns. “I think that if an engineer did a survey on his own work, that would be good. To have others do it, then it would have to be under controlled conditions before I would go along with it,” he says. “If the purpose is to do a witch hunt or something, then I’m not for it.”

“There is a host of reasons why the building may not be operating like it’s supposed to,” Needra continues. “Some of them may be the responsibility of the designers, some may be the responsibility of the builders, and some may be the responsibility of the owners in maintenance.”

If consultants have to worry that an evaluation might bring on a lawsuit, building owners could have other fears. Trade unions could seize on survey results that show shortcomings in the workplace as a negotiating tool. Tenants might use reported deficits in the building as an excuse to default on their rent.

The cost and time ne
cessary to conduct an evaluation could also be a deterrent. Hyde is aiming to make the protocol process possible for $10,000. And she suggests that the building’s design consultants should pay a portion — with recent evaluations she’s asked for just over $1,000.

Creating a culture of doing evaluations

Why should consultants pay to go through what could be a tortuous process as their buildings come under scrutiny? Hyde hopes it is because they will see the educational value and benefits. In fact, she argues that doing retroactive building reviews are a professional duty.

“The client could be excused for assuming that we are [already] evaluating our work,” she says. “Why wouldn’t that be the case?”

“Well, the fact is,” she continues, “that it is very rare for designers to do post occupancy building evaluations on a structured basis. The good designers go back and chat with the occupants and say, what do you like about [the building], but it’s relatively informal even for them.”

What about energy contracting? Doesn’t that include a strong component of building performance evaluation? Hyde’s answer is that energy contractors will closely monitor the utility bills, but not the occupants’ satisfaction. “And that’s a problem,” she says, adding half-jokingly, “because you can get great energy efficiency by nailing up the air intakes.”

Hyde likes the fact that the building performance protocol is now freely available to the design community in Canada. Other evaluation protocols tend to be proprietary. Also this protocol is designed for use in North America rather than Europe. Since it is in the public domain, it can be used widely to provide uniform results, and not just for green buildings. “The long-term picture is to create a culture of doing post-occupancy evaluations,” Hyde explains.

Hyde passes on a paper written in 2001 by Craig Zimring, of the Georgia Institute of Technology. In the paper, Zimring recognizes that designers will feel apprehensive about post occupancy evaluations. But he says evaluations are essential for design to evolve: “Learning involves risk and change. To learn we have to expose when we make mistakes so we can improve…. Imagine for a minute learning to play golf, but not knowing whether the ball went toward the flag or not!”

In other words, doing building design without having performance evaluations to indicate the right direction, is virtually like driving off blind.

1 Stantec contracted out some processing of the occupant survey to the Center for the Built Environment at the University of California at Berkeley (www.cbe.berkeley.edu).

BUILDING PERFORMANCE EVALUATIONS — WHAT’S INVOLVED

By 2005, Dr. Hyde of Stantec and a team of other experts had developed a more elaborate protocol for evaluating buildings than the one piloted in 2004. This more detailed review procedure, renamed “Building Performance Evaluations,” was developed with input from faculty at the University of B.C. and architects Busby Perkins + Will.

Besides analyzing utility bills and doing occupant surveys, the revised protocol requires the evaluating team to use instruments to measure objectively the environmental conditions of a building. The evaluators measure thermal temperature and radiant temperature, air movement and relative humidity in 10 different locations. They also measure air quality, lighting and acoustic levels. They take into account the time of day, and how busy the space is at the time.

During the evaluation process, the building occupants and operators are interviewed at various stages. During “Kick-off” and “Wrap-up” discussions the design team gets to explain their design intentions and compare them with the evaluated results.

The 2005 protocol was developed with funding by Industry Canada, Terasen Gas and Clivus Multrum. The EcoSmart Foundation has used it to evaluate a second series of buildings and has posted the document on its website, www.sbtc.ca


Print this page

Related Stories

Leave a Reply

Your email address will not be published. Required fields are marked *

*