Publicly owned rental housing will be thrust into the role of demonstrating how greenhouse gas (GHG) emissions from Vancouver’s building stock can be significantly reduced. However, the city’s newly adopted Zero Emissions Building Plan (ZEBP) ultimately demands similar results from all types of new development, with the goal of entirely eliminating emissions by 2030.
It sets out a two-part strategy to ensure that new buildings are as energy-efficient as possible and, perhaps more contentiously, do not rely on natural gas for space heating and hot water supply. In turn, the city has pledged to support research and peer networking in the green building sector and to ease regulatory requirements that can undermine or add to the cost of innovative energy-efficient designs.
The preamble to the plan, which Council formally approved last week, includes some weighty objectives.
“These strategies for achieving zero emissions in new buildings were developed specifically to ensure comfortable and healthy indoor environments, maximize local economic development, ensure long-term building resilience, protect housing affordability and facilitate achieving the City’s Renewable City Strategy target to have all buildings in Vancouver, including those already built, use only renewable energy by the year 2050,” it states.
Others characterize the effort in less intimidating terms.
“The aim is to get the energy consumption as low as we can and then use renewable energy sources to supply the balance,” says Brittany Coughlin, an engineer and energy and sustainability specialist with RDH Building Science Inc. in Vancouver. “There is a lot that is achievable and realistic. It’s not based on crazy new technology; it’s things we are already doing in a lot of cases.”
B.C.’s electricity supply, estimated to be 97 per cent generated from hydroelectric and other renewable sources, supports options like heat pumps or even electric baseboards that wouldn’t pass the emission-free bar in some other jurisdictions. Electricity, bio-gas and neighbourhood renewable energy systems (NRES) are foreseen as the primary alternatives to fossil fuels, although builders will have flexibility to incorporate solar photovoltaics or other on-site renewable generation to meet near-zero or zero-emission targets.
Civic leadership with industry buy-in
Vancouver has now become a North American leader in pursuing zero GHG emissions in new construction. The envisioned incremental phase-down — cutting allowable emissions to 30 per cent of 2007 levels by 2020 and to 10 per cent by 2025 — is a similar schedule to the European Union’s nearly-zero energy buildings (nZEB) target, which was endorsed in 2010 with the goal that all new buildings would comply by December 31, 2020.
Even proponents of that EU target such as the European Council for an Energy-Efficient Economy concede the 2020 deadline will probably not be met, but Vancouver has some strategic advantages that might make its goal more realistic. Beyond a low-carbon electricity supply, the moderate climate means generally less onerous heating and cooling loads and the city even has its own building code, giving local decision makers more direct and expeditious administrative control.
“B.C. has the easiest conditions so it makes sense that they would move first on this,” observes Doug Webber, vice president, sustainability and energy, with the engineering consulting firm, WSP Group. Meanwhile, real estate industry advocates commend the city’s consultation process and the motives behind it.
In a July 11 letter to Vancouver Council, Anne McMullin, president and CEO of the Urban Development Institute’s Pacific region, thanked city staff for openness to her membership’s concerns over 18 months of work on the plan and affirmed the industry’s support for the phased approach to compliance.
“This will allow capacity in the industry to expand as the standards do,” she stated. “The targets, including the early ones, will be difficult to meet. They are achievable, but we need to ensure that [some] issues are addressed.”
“It’s a very ambitious program to meet some very ambitious targets,” concurs Brooks Barnett, manager, government relations and policy, with the Real Property Association of Canada (REALpac). “If there’s a concern with it, it would be about the timelines, but, fundamentally, it’s the right way to go.”
Passive House standard endorsed
City officials have identified the Passive House standard as the recommended means for delivering required reductions in thermal energy demand intensity (TEDI). Passive House design, calculated to achieve heating and cooling energy-use intensity no greater than 1.4 kilowatt-hours per square foot, is considered a particularly good fit for residential development since it downplays complicated technologies that require more operational expertise and places more emphasis on high-performance building envelopes and relatively simple ventilation systems.
“Very good draft proofing and the use of a heat recovery ventilator (HRV) that uses the energy of warm exhaust air to pre-heat fresh incoming air during the winter and vice versa during the summer are central to an energy-efficient ventilation system,” the ZEBP advises. “Given that 82 per cent of new development in Vancouver is residential and that most homeowners, strata councils and apartment building operators are not building energy system experts, keeping the building systems simple is essential to reliable and durable building energy efficiency performance.”
The Passive House standard is still a rarity in the broad scope of new construction, but a growing number of practitioners are gaining expertise in design, construction and development of supporting products, including customized energy modelling software. The ZEBP endorses Passive House as a “rigorous and widely applied global standard” now physically translated into hundreds of millions of square feet of real estate around the world, but acknowledges “there is insufficient local data to conclude that this standard should be applied to all building types under all conditions”. To date, there are relatively few examples of institutional, commercial or multi-residential buildings constructed to the standard and a fairly steep learning curve yet to negotiate.
“Passive House is not well developed for commercial buildings. We will see if developers can deliver,” Webber says.
Cost-benefits analyses invariably focus on the long-term operational savings that come with energy efficiency, but Passive House and other more innovative and aggressive design approaches can result in upfront capital savings via significant downsizing of high-cost mechanical systems that would otherwise be required to heat, cool and ventilate the building. Prefabricated building envelope is another emerging trend that could also reduce on-site construction costs.
“Just looking at a line-by-line comparison for better-than-code or Passive House or net zero versus code compliant, you are going to see an added cost anywhere from 2 to 10 per cent. However, we are also seeing that there are other costs that can be reduced that could really dwarf any extra incremental costs for building to the higher performance standard,” Coughlin says.
The City of Vancouver has committed to building its own affordable rental housing projects and other required new facilities to the Passive House standard, and is amending the previous policy requiring LEED Gold certification to reflect the new direction. The much larger provincial developer and manager of subsidized housing, BC Housing, is also on board, drawing from its experience in building 34 LEED Gold projects.
“Given all of the sustainable new construction projects completed, BC Housing has found that those with simple designs that rely primarily on passive elements rather than complex mechanical systems use less energy and are easier and more affordable to maintain,” the ZEBP reports. “They have targeted Passive House certification in RFPs for several recent new construction projects.”
Barbara Carss is editor-in-chief of Canadian Property Management.