Project Kick Off: What is a Deep Energy Retrofit?

4 Elements Integrated Design
5 min readOct 14, 2022

We have been diving deep into the process for our Deep Energy Retrofit + Electrification project with SSRIA and an amazing team of industry experts, including project partners True Aim Concepts and SAIT Polytechnic. The goal of this project is to prove the viability and replicability of Deep Energy Retrofits. This project will provide results as case studies of three Calgary homes that are undergoing Deep Energy Retrofits as they are renovated to meet future energy codes and lower carbon emissions.

Image: Adding exterior insulation in a Deep Energy Retrofit. Source: 4 Elements Integrated Design Ltd.

What is a DER?

While renovations are a common and integral part of homeownership, Deep Energy Retrofits (DER) are emerging as a new type of home renovation. Where most renovations focus around maintenance, expansion, or updates, a DER looks at the performance of the home, and pushes the home’s performance past current standards towards future code levels and the needed performance in 15 to 20 years.

Homes age over time and maintenance, renovation, and retrofits have always been needed periodically. Here’s a quick summary of the differences between these concepts:

Maintenance and Repair

Periodic work to ensure the home’s envelope and mechanical systems last as long as possible. Examples include repairing a blower motor in an existing furnace or replacing weather stripping.


Updating individual systems when they reach end of life due to use, style, or function. Examples are kitchen renovations of older cabinets with a modern open style, replacing a few failing windows, or updating a broken furnace.


Major rehabilitation and replacement of multiple systems and infrastructure to advance the level of performance and function to minimum current standards. An example is retrofitting a coal-fired gravity furnace with a natural gas furnace.

Deep Energy Retrofit

Similar to a retrofit, but a DER takes a ‘house-as-a-system’ approach that improves both systems and infrastructure beyond current requirements to higher possible levels. Infrastructure completely moves away or prepares to move away from fossil fuels and has drastic reductions in energy demand and use.

A stack of new windows lay against a fence.
Image: Replacement and upgrade of multiple windows. Source: 4 Elements Integrated Design Ltd.

When doing a “normal” retrofit, new work must be compliant with today’s code. If changed, wiring, insulation, or mechanical systems must meet current standards for efficiency. While this might improve a home from 10% — 15%, a DER focusing on energy efficiency pushes performance up to 70% — 100%.

The following are common features of a DER:

Envelope Improvements

The envelope is what separates the outside environment from the inside environment. It includes insulation, windows, and air tightness on all exterior surfaces. Thick insulation and extreme air tightness greatly reduce the required size of the heating system and the annual energy consumption.

Mechanical System Improvements

Space heating and domestic hot water heating are major household energy uses. DER prepares for a fossil-free future energy grid and uses very efficient equipment, such as electric heat pumps. This provides even further energy savings.

Renewable Energy Installations

Installed or planned-for future implementation, renewable energy is the icing on the cake making these energy efficient homes fully “net zero” (uses no energy on an annual basis). Solar provides a significant energy cost savings and reduces operational carbon emissions.

Three wires on a roof, with a conduit going down the side of an unfinished building.
Image: Adding a solar conduit for a future solar photovoltaic system installation. Source: 4 Elements Integrated Design Ltd.

Why do a DER on your home?

Since the early 1940’s, Canadian homes have been required to meet minimum standards in how they are built and what products are used in them. Many earlier homes were susceptible to fire, structural failure, or water damage due to poor practices and shoddy construction. The building code was introduced to show what was acceptable and what was not, giving homeowners and cities enforceable instructions to protect inhabitants and owners. Today we say that most of the building code was “written in blood”, learning from accidents, disasters, and wide spread failures became the basis for code clauses that protect us now.

When you buy an older home, many aspects may not be “up to code” meaning these features are not compliant with today’s standards. For example, bedroom windows might be too small to get out of in a fire, wring may be more susceptible to shock and fire, and insulation may be missing or limited.

Here are some examples from our three case study homes built between the 1950 and 60’s:

Table: Inadequate ventilation: limited or no exhaust or fresh air supply. Code Required in 1990’s. Spillage susceptible mechanical equipment causing carbon monoxide poisoning risk. Code Required in 2010’s.  Single and double pane windows susceptible to frosting and water damage. Code Required in 2020’s.  R11 walls with poor air sealing, increasing energy costs and carbon emissions. Code Required R14 in 1980’s , code Required R17.5 in 2010’s.
Table of examples from our three case study homes built between 1950 and 60’s.

Our case study homes were very typical of houses built during that time, with various renovations over the decades to replace or update features, for example: a new window, or newer furnaces and hot water tanks. But even that newer product’s annual energy consumption was much higher than today’s code standards.

Even today’s building code, the most stringent Canada has ever had, is still far below best practices of high-performance homes that a growing number of Canadians are choosing. Here are some examples from our work in Net Zero Homes:

Table: Code requirement for Ceiling insulation: R60 Net zero requirement for Ceiling insulation: R80.
 Code requirement for Wall insulation: R17.5. Net zero requirement for Wall insulation: R27 to 35.
 Code requirement for Furnaces: 92%. Net zero requirement for Efficient Heatpumps: 300% Efficient.
 Code requirement for Double Glazed Windows: 1.6 U-Value. Net zero requirement for Triple Glazed Windows: 0.95 U-Value.
Table of code requirements vs Net Zero requirements.

While Canada builds over 100,000 homes a year, only a small fraction, about 100–200 are built to these very high-performance standards. But existing homes can be renovated to these high levels in a Deep Energy Retrofit. Innovative builders and renovators across Canada have shown just how efficient, comfortable, and quiet these new Net Zero homes can be. While leading today, these homes will be the standard as the upcoming 2020 National Building Code leads homes to be net zero ready by 2030. Building to these high standards sooner will provide you with the full range of benefits and operational savings high-performance homes have that won’t be commonplace until enforced in 30 years. While most 30-year-old homes are far below current standards, we have the opportunity now to build and renovate homes that will still meet or exceed requirements far into the future.

A properly planned, fully executed DER provides dramatic energy savings, energy cost savings, and carbon emissions savings. If you’d like to learn more about this project, check out the project page on SSRIA’s website, and stay tuned to our social media (LinkedIn, Facebook, Twitter, Instagram, & Blog) for more updates!

Funding for this project is provided by the Smart Sustainable Resilient Infrastructure Association (SSRIA) as part of their Green Building Technology Network (GBTN) program. SSRIA is a not-for-profit association in Alberta that is fostering collaborative and innovative solutions that can achieve a path to 40% greenhouse gas emission reductions by 2030 while positioning Canada as a global leader in the Architecture, Engineering, and Construction Industry. SSRIA also supports the growth of Alberta SMEs who are developing innovative building products and technologies and ensures the current and emerging workforce have the necessary skills to work with those innovations.



4 Elements Integrated Design

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