Time for zero carbon housing and buildings in BC

BC needs a lot of new affordable housing and any build out should ensure that it meets the highest standards for energy efficiency, including zero-carbon operations. Residential, commercial and institutional buildings produce 11% of BC’s GHG emissions, mainly from burning natural gas for heating and hot water.

Updated building codes are needed to make the deployment of these techniques mandatory within the next few years. The BC Step Code is moving in this direction with its “net-zero ready” Step 4 to be mandatory for all new buildings as of 2032. Strong regulations like this are important, but the timeline for implementation is way too long in light of the climate emergency.

This next generation of housing should be largely composed of mid-rise, wood-frame buildings built to passive house standards, with affordability aided by economies of scale in utilizing standard designs, modularized components and a dedicated workforce. In passive house construction there is minimal need for energy for heating/cooling and hot water, which constitute most current energy demand from buildings.

Such a shift means all new buildings need space and water heating using zero-carbon sources, primarily electricity. However, it need not be the case that every gigajoule of fossil fuel is replaced by a gigajoule of grid electricity. Major gains in efficiency are possible for buildings as it is already possible to build to passive housing standards, which require little energy input. In addition, buildings themselves can be equipped to generate their own electricity (solar panels) and heat (solar hot water). With good upfront design of efficient building envelopes, mechanical and ventilation systems, passive house building costs about the same as conventional buildings per square foot.

In addition to the energy needed to operate a building, we also want to shrink a building’s embodied carbon during construction. Materials such as concrete and steel have high embodied carbon compared to wood, which locks away carbon for the lifetime of the building, perhaps hundreds of years into the future. Expanding the market for wood in BC buildings and elsewhere is also good news for BC’s forestry industry, and an opportunity to displace negative trends like increasing raw log exports. The total cost of construction and the amount of concrete used can also drop substantially if minimum parking requirements were to be eliminated and thus the need for digging deep concrete parkades.

For existing homes, better insulation, programable thermostats and other building retrofits have the potential to reduce household energy demand. What’s more, it is well established that improved energy efficiency and conservation is where we get the best “bang-for-the-buck” returns when it comes to energy investments. These would be accompanied by fuel switching from gas to electricity in the form of heat pumps (as opposed to conventional electric baseboard heating, which is much less efficient).  Such a deep retrofit would ensure that monthly operating costs are comparable to the status quo of low-cost natural gas.

The up-front capital cost, however, of converting one’s home heating to electric heat pumps can be very steep. So low- and middle-income families will need financial help to make the switch (and for renters, their landlords). Government action and mass adoption of heat pumps, however, can also significantly reduce their cost. Heat pumps and their installation in much of Asia, for example, is much cheaper because they are the norm and economies of scale and building codes make their use much less expensive.

Notably, societies have quickly transitioned home heating sources before. In England, prior to the 1960s, most homes used what was called “Town Gas”—a particularly volatile and noxious coal-derived gas—delivered by municipal pipe. Town/coal gas also had a high level of carbon monoxide and its use was associated with distressingly high suicide rates. The dangers with town gas convinced the government that it should be phased out and replaced by the much-safer natural gas. That decision necessitated replacing all home appliances (the burners were quite different) and this was done over a 10-year period.

BC should thus commit to fully phasing out the use of fossil fuels for domestic purposes to clearly signal that we are on a wind-down path. Following the lead of places like Berkeley, California, BC should announce that—within the next one to two years—no new buildings (residential, commercial or public such as hospitals and schools) will be allowed to use natural gas or tie into natural gas pipelines. All new buildings would need to use electric, heat pump, space and hot water heating and next-generation electric induction stoves.

In addition, the province should regulate that all existing buildings will need to be off gas by 2040 and develop transition plans starting with older, less-efficient building stock. Commercial, institutional and industrial users should also be given an intermediate timeline to phase out their use of gas. The key point here is that if we are to truly wind down domestic use of gas, we need to move beyond incentives and rebates and simply mandate a timetable by which these fuel-switches are the law.

Topics: Climate change & energy policy, Environment, resources & sustainability