This article originally appeared in the Spring 2024 issue of Western Built magazine.
Deep Energy Retrofits have caught on as a hot topic for building owners looking to decarbonize their assets, but entry costs are perceived as high, and many are struggling to take the first step. In this article, Entuitive’s Heather Elliot, Senior Associate, Building Envelope, and Sam Lane, Associate, Discipline Lead for Sustainability + Performance , will outline the process and pathway for building owners to initiate the reduction of emissions and energy in their existing buildings.
The path to building decarbonization within our industry won’t be a straightforward one. There are roadblocks, indeed, but no detour available to achieving far - reaching, pivotal sustainability goals. The most impactful solutions often require collaboration, open - mindedness, and an understanding of how important it is to act.
With the building industry said to be responsible for 40 per cent of global GHG emissions, building codes are addressing the impact of new construction on climate change. Further changes in legislation, building regulations, and emissions standards continue to appear across Canada and the U.S. Standards such as zero - carbon and zero - energy buildings designations. For instance, Vancouver has published a timeline for their GHG emissions limits, with reporting for large commercial buildings starting this year and limits coming into force in 2027.
However, given that two - thirds of the buildings that exist today will still exist in 2050 and we need to retrofit a building a minute from now until then to meet the targets we’ve already set , we know existing buildings need to be a huge piece of the solution. With the importance of whole life carbon, the solution cannot be to demolish and rebuild all inefficient buildings, but instead we need to treat our existing buildings as a carbon resource and improve them at scale.
How to Decarbonize?
With decarbonization, the industry must take a tiered approach in order to establish where the most impact can be made. First, attention should be focused on the biggest offenders for emissions. Assuming low - hanging fruit like lighting upgrades have already been completed, the next step would be to lower the emissions associated with space heating and cooling. These are typically the best bets to reduce emissions . Specific tactics to achieve this are fuel switching, equipment selection, and demand reduction.
A first question to ask should be, “Are we using fossil fuels in the building?” and “How green is the local electrical grid?” By understanding the local electrification options, stakeholders can plan for whether electrification is an immediate, short term, or long-term opportunity. It is an easy bet that 50 years from now all buildings will be electrified, but the crystal ball is blurrier in the next decade or two.
Fuel switching (ie. from fossil fuels to electricity), can be very effective in clean grid locations but can require increased electrical service capacity and increase utility costs dramatically.
Improving efficiency through equipment selection, such as heat pumps including ground-source heat exchange, can be very impactful but there are drawbacks. In many buildings, this will require a new low-temperature distribution system which can be prohibitively costly and disruptive to install.
As for reducing demand, this is often recommended as the first step in a decarbonization retrofit. Unfortunately, the payback periods for demand reduction strategies (which usually include improving the building envelope) are traditionally longer and daunting. Justifying these improvements on energy cost savings alone can be tricky as so many non-contributing systems (cladding, structure, drywall) have to be upgraded to improve the performance.
Over its 26 years of service, the Canada Games Aquatic Centre in Kamloops, British Columbia, was maintained, but never upgraded. Large scale renovations in 2020 aimed to increase overall building durability with innovative envelope and mechanical system solutions, reduce energy use, and reduce greenhouse gas (GHG) emissions. Photo courtesy of Kathleen Fisher.
Deep Energy Retrofits - Are They the Solution?
Deep Energy Retrofits (DERs) are a term the industry has settled on to describe the soup-to-nuts process of improving a building’s performance with the goal of achieving significant building improvements to energy consumption or GHG emissions. These projects tend to follow a demand reduction first policy, using improvements to the building envelope to justify smaller HVAC and renewable systems to hit the project’s targets. We have been fortunate to lead and contribute to a range of deep energy retrofit projects and have seen them work wonderfully for our clients.
Initiating a Deep Energy Retrofit project involves a series of key steps and considerations aimed at maximizing energy savings and enhancing building performance.
Entuitive has successfully employed this process on major building retrofits. We have seen the best examples of what a DER can be; however, the DER process is not always scalable. The projects are typically well-funded, often through public funding as a demonstration project, and they usually require partial, staged, or full de-occupation of the building. Although there are many examples across Canada of DERs achieving great success, they may not provide a viable solution for retrofitting en masse. Many retrofit projects are shelved after the feasibility stage, with the retrofit being deemed not feasible due to cost or practicality. Sometimes, the pool is a little too deep for everyone to swim in.
Is There Another Solution?
In our search for a solution to achieving retrofits at-scale and making them more accessible, we came across the Pareto Principle. Vilfredo Pareto, was an Italian Polymath who first observed that 80% of the wealth in Italy belonged to only 20% of the population. This 80/20 split has been coined the ‘Pareto Principle’ and has been applied to a broad variety of topics. At a high level, oftentimes 80% of the effects or outcome is produced by 20% of the causes. When applied to the objective of retrofitting a building, identifying the few changes to be made can often have the most significant impact on the building’s performance. Tongue in cheek, we’re calling this method the ‘shallow energy retrofit’ - a pool that more buildings can play in.
Shallow energy retrofits prioritize gradual enhancements over extensive building overhauls, recognizing buildings as evolving entities with decarbonization goals tied to specific years (2030? 2040? 2050?). Fundamental to the shallow energy retrofit is tying the decarbonization plan to capital planning, pinpointing when is most strategic to enact a performance upgrades. Analysis and understanding the building owner’s goals drives the process, revealing energy consumption patterns and retrofit opportunities.
The first step to a shallow energy retrofit is understanding demand. Older buildings often include drastically oversized heating plants. We recommend building owners conduct some high-level systems metering before the feasibility study stage to get a sense of whether their plant is oversized. Conducting six months of metering to observe how the building functions on the coldest and hottest days can give building owners the confidence to right-size systems. If we budgeted for a like-for-like replacement but can put in a smaller one, suddenly we would have capital available to spend on improved systems.
Defining what decarbonization means to the building owner is an important step that should be discussed before an RFP is on the table. This means asking some important questions like:
1. What are your goals?
2. Do you understand which regulations are applicable and coming?
3. How do you define terms like “Net Zero” or “Net Zero Ready”?