The promise and pitfalls of new
green building policies:
Can district energy thrive?
New Canadian green building policies focusing on carbon emissions – rather than just
energy – offer new opportunities for district solutions in fighting climate change.
Gerard MacDonald, PEng, LEED AP, Principal, Reshape Strategies; and Trent Berry, Principal, Reshape Strategies
Building codes, like district energy, have existed since antiquity. The arliest codes emerged to protect health and safety. More recently
they have evolved to regulate energy use,
and now carbon emissions from buildings.
Energy considerations emerged after
World War I in the form of minimum insulation levels in some northern regions.
The initial focus was occupant comfort,
but their scope expanded in response to
the 1970s oil crisis. By the 1990s, most
member countries of the Organisation for
Economic Co-operation and Development
had introduced and increased provisions
for energy efficiency in building codes.
In recent years, green building poli-
cies have evolved from an exclusive focus
house gas emissions. It is therefore pos-
sible for buildings to achieve higher steps
without actually reducing emissions and
possibly even increasing them relative to
buildings at lower steps that used lower-
carbon fuels (fig. 1). 2
In contrast to the Energy Step Code,
the city of Vancouver recently introduced
a Zero Emissions Building Plan that includes explicit requirements for greenhouse gas emissions. 3 Other Canadian cities such as Toronto have begun to follow
suit. We think this will become the norm
as governments get serious about meeting greenhouse gas reduction targets.
But what do these emerging green building policies mean for district energy? In
the right circumstances, district energy
can increase efficiency (or achieve comparable efficiency at lower cost). But district energy offers far more promise as a
tool for combating climate change and increasing resilience. The value proposition
for district energy is typically enhanced
by the introduction of a greenhouse gas
District energy can tap low-carbon
energy sources not available, appropriate
or adequate at individual development
sites. District energy can lower the cost of
greenhouse gas reductions through econ-
omies of scale and integration of different
building types. Lower costs are essential
to gaining public acceptance of deep
greenhouse gas reductions. Compared to
building-scale energy systems, district en-
ergy exhibits less technology lock-in and
on energy efficiency to consider green-
house gas emissions. 1 Increased efficien-
cy does not necessarily equate with lower
greenhouse gas emissions: The selection
of energy sources can be of equal or
In British Columbia, the provincial
government recently introduced a voluntary, performance-based “Energy Step
Code” to lower energy use in buildings.
Communities can adopt one of four steps
in the code; the higher steps require
lower-energy-use buildings. This code
is to be commended for requiring lower
energy demand from buildings, but it is
“fuel-neutral” – meaning it ignores which
input fuel is used to heat a building, with
no explicit requirement to reduce green-
FIGURE 1. Greenhouse gas emissions of alternate compliance pathways for the BC Energy Step
Code for a high-rise multiunit residential building.* British Columbia’s new Energy Step Code
is fuel-neutral, but greenhouse gas emissions intensities are actually more dependent on the
selection of energy sources.
* Emissions intensities are specific to British Columbia.
1 kg/sq ft = 10. 76 kg/sq m
Source: Reshape Strategies and Morrison Hershfield.
Courtesy Westbank Corp.
Greenhouse gas intensity
(kg CO2e/sq m)** System Step level
Telus Garden in Vancouver.