Whole Home Sustainable Renovations in BC: Deep Energy Retrofits and Embodied Carbon Reduction

Coast Essential Construction is proud to build in British Columbia, which continues to lead Canada in sustainability and climate resilience through the BC Energy Step Code for new homes. BC homeowners and renovation contractors are increasingly embarking on whole-home sustainable renovations. There are two foundational pillars of this renovation movement, deep energy retrofits (DERs) and the reduction of embodied carbon. They currently offer the two most promising pathways for significantly lowering the carbon footprint of BC’s residential building stock.

The urgency of sustainable renovations

BC is committed to reducing province-wide emissions by 40 percent from 2007 levels, and has set a target to reduce emissions in buildings and communities by more than a half by 2030. Buildings create almost 60% of the greenhouse gas emissions in Vancouver, for example, and most of the province’s housing stock already exists. This means new construction alone won’t achieve its legally mandated climate targets for buildings and communities by 2030. British Columbia’s CleanBC Roadmap to 2030 and BC Energy Step Code have placed the province at the forefront of building energy performance standards in Canada.

Many existing homes rely on natural gas or oil for heating, with systems that need to be replaced with electric heat pumps or other clean energy alternatives. Deep Energy Retrofit (DER) projects also aim to reduce older homes’ annual energy demand by more than 50% and carbon emissions by roughly 80%, with building envelope upgrades that reduce thermal heat loss, drafts, and moisture problems, while improving indoor air quality and comfort.

To meet these targets, tens of billions of dollars must be mobilized, reflecting the massive scale of the retrofits that are needed across BC’s existing housing stock. The province has launched several programs that provide incentives and rebates to encourage homeowners to undertake the upgrades, but the scope of work is daunting.

What is a deep energy retrofit (DER)?

Deep energy retrofits are a comprehensive upgrade of an existing building to drastically reduce its energy use. The energy efficiency improvement under the program is 50% or more, and it also increases the comfort and health of the homeowners, while adding durability and resilience. Unlike undertaking piecemeal improvements, such as adding insulation or replacing a furnace, DER projects take a whole-systems approach. The interactions between components like the building envelope, mechanical systems, ventilation, and occupant behaviour are examined and factored into the redesign.

 Building envelope upgrades: Adding continuous rigid foam board insulation to the outside of the house, or increasing the insulation in walls, attics, roofs, and floors, minimizes heat loss and gain. Spray foam or blown-in insulation is often used to fill gaps, and air leaks are sealed with weatherstripping and caulking, providing continuous insulation and maximizing insulation effectiveness. Moisture and thermal bridge management avoid mould and condensation, which is particularly important in the BC West Coast’s humid and wet climate.

Windows and doors are usually the weakest thermal link in your building envelope. High-performance windows and doors are critical components in a deep energy retrofit. These units typically feature double or triple glazing, low-emissivity (low-E) coatings, and insulated frames to significantly reduce unwanted heat transfer between your living environment and the outdoors. Triple-glazed, argon-filled windows with fibreglass frames can achieve centre-of-glass R-values as high as R-8, and they offer exceptional thermal resistance.

In addition to the significant reduction in your energy bills, your family will enjoy stable indoor temperatures, free from drafts, while reducing the load on your heating and cooling systems.

 Heating, ventilation, and air conditioning (HVAC) improvements: Carefully integrated with building envelope enhancements, heating, ventilation, and air conditioning (HVAC) system upgrades play a central role in increasing your home’s energy efficiency during a deep energy retrofit. Today’s HVAC systems, such as high-efficiency air-source heat pumps, furnaces, or ground-source heat pumps, will typically replace older, less efficient units. They use less energy to maintain comfortable indoor temperatures year-round, which leads to lower utility bills.

Programmable or smart thermostats allow you to set customized heating and cooling schedules, so energy is only used when it’s needed. Zoning systems allow different areas in your home to be heated and cooled independently, to further reduce energy waste.

With an airtight building envelope, a mechanical ventilation system, such as a heat recovery ventilator (HRV) or energy recovery ventilator (ERV), becomes essential. Mechanical ventilation systems ensure healthy HEPA-filtered air quality while recovering heat from the exhaust air stream, to conserve energy. Heating and cooling ducts are properly sealed to prevent air leaks, ensuring that conditioned air reaches its intended destinations efficiently.

 Lighting and appliances: Upgrading your home’s traditional incandescent or fluorescent bulbs to LED lighting significantly reduces the amount of electricity used for illumination. LEDs are more efficient, they have longer lifespans, and they generate less heat. Adding lighting controls, such as dimmers, timers and occupancy sensors, is another way to minimize energy use.

Replacing old, inefficient appliances with Energy Star® rated high-efficiency models reduces the energy required for cooking, refrigeration, laundry and dishwashing. Today’s appliances often have energy-saving features like smart scheduling, load sensing, and improved insulation.

Energy used by devices plugged into outlets, such as electronics and chargers is another important consideration. Using advanced power strips, unplugging unused devices, and selecting low-standby-power products can significantly reduce your household plug loads. Addressing energy loads such as lighting, appliances and plug loads enables DERs to achieve household energy reductions of 50% to 90%.

 Water efficiency: Water-saving measures are often integrated alongside energy upgrades during deep energy retrofits, to maximize resource conservation and operational cost savings. Installing low-flow fixtures, such as faucets, showerheads and toilets, and upgrading to high-efficiency appliances such as dishwashers and washing machines are one of the best ways to reduce the amount of water used by your household.

Heating water is a significant energy load in most modern homes, so lowering consumption directly decreases the energy required for heating water as well. Upgrading to tankless/on-demand or heat pump water heaters is a way to reduce the energy requirements for supplying hot water even further. Reductions in both energy and water use during a DER can result in water cost savings of up to 50%.

 Roofing and renewable energy: Upgrading or replacing the roof as part of a DER often involves adding superior insulation and fixing air leaks. Installing cool or reflective roofing materials helps reflect light, thereby reducing heat absorption and lowering the home’s cooling loads. In addition to extending your roof’s lifespan, a new roof can require less maintenance and it will better withstand extreme weather, contributing to the long-term durability of the home’s building envelope.

While not an essential part of a deep energy retrofit, adding a renewable energy source such as solar photovoltaic (PV) panels has become a popular add-on. A renewable energy system enables your home to generate its own electricity, offsetting or eliminating grid energy reliance.

When combined with a reduction of energy demand, resulting from the envelope and system upgrades, on-site renewables can help your home achieve net zero energy status. A net zero home produces as much energy as it consumes annually. Net zero energy (NZE) homes have significantly lower energy bills, due to their increased energy efficiency, and by covering energy demands with clean renewable energy. Net zero homes are more resilient to energy price fluctuations and potential grid outages, with a battery energy storage system (BESS).

Embodied carbon: the hidden emissions

Most of the discussions on sustainability today are focused on the operational energy: heating, cooling, lighting and appliances. But there’s another angle to the carbon equation that needs to be included in that discussion: embodied carbon. Embodied carbon represents the total greenhouse gas emissions generated through the production, transportation, installation, maintenance, and disposal of building materials.

For renovations and retrofits, these include everything from the insulation and drywall to concrete and framing lumber… right down to the fasteners. As renovated homes become more energy-efficient, embodied carbon can account for 50% or more of the building’s total life-cycle emissions. Reducing carbon is therefore a critical consideration in planning a successful sustainable renovation.

Strategies for reducing embodied carbon in whole home renovations

 Prioritizing retrofits over demolition: Retaining the existing structure, foundation, and framing is one of the best ways to avoid embodied emissions. A deep retrofit can preserve the carbon already stored in its materials, while a full or partial teardown would add a substantial amount of new carbon.

 Use of low-carbon materials: The selection of materials is critical because the upfront emissions from retrofits can more than offset operational carbon savings, if not managed carefully. Wood and engineered timber, sustainably harvested and mass timber, not only have low embodied carbon but will store carbon over the home’s lifetime. Manufactured from recycled paper, cellulose is a carbon-storing material that has significantly lower embodied carbon than foam or mineral wool insulation products. While mineral wool insulation does not store carbon, it has a lower embodied carbon than foam-based insulations.

Recycled content materials such as recycled steel, aluminum, and glass reduce the need for extracting new raw materials. Concrete mixes with supplementary cementitious materials, such as fly ash or slag, or carbon-sequestering additives can reduce the high emissions associated with traditional concrete. Prefabricated exterior wall panels are becoming popular in renovations; manufactured from low-carbon materials, they streamline the installation process and minimize waste, to reduce embodied carbon.

 Designing for longevity and adaptability: By extending the useful life of the building materials, and minimizing the need for future resource-intensive renovations or replacements, your renovation project can significantly reduce the embodied carbon of the home. By choosing durable materials, focusing on robust construction, and creating layouts that can be easily adapted to changing needs, the total carbon emissions associated with producing, transporting, and installing new materials are spread over a much longer period.

Homes with a short service life, of say 25 years, have annualized materials-driven carbon impacts that are 120% higher than those designed to last 60 to 80 years, which can reduce the life cycle embodied carbon emissions by up to threefold.
 Minimizing waste and transportation: Careful planning during the design phase, and using prefabricated or modular components can significantly reduce construction waste. This means fewer new materials need to be extracted, manufactured and processed. Project design should also factor in deconstruction and diverting materials away from traditional landfill sites to more sustainable methods like recycling and reuse. Designing for easy future disassembly and reuse of materials will further reduce waste and embodied carbon.

Transporting materials for long distances requires a lot of energy, particularly for heavy materials like concrete and steel. Sourcing materials locally reduces the carbon footprint associated with shipping, while helping to stimulate the local economy.

Incentives and rebates in BC

 CleanBC Better Homes:Better Homes BC offers over $12,000 in available rebates available when you replace a fossil fuel-based appliance with an electric one. The Energy Savings Program offers enhanced rebates to make energy-saving home upgrades more affordable, based on your household income, with rebates up to to $44,900.

 BC Hydro and FortisBC programs:: Energy Saving Kits are available from BC Hydro and FortisBC for income-qualified households. Energy saver kits include a water-efficient showerhead, kitchen and bathroom faucet aerators, weather-stripping, window film, outlet and switch plate sealers, a refrigerator/freezer thermometer, an LED night light and four LED light bulbs. For FortisBC gas customers there’s also a furnace filter coupon.

Rebates of up to $10,000 are available from BC Hydro for purchasing and installing solar panels and battery energy storage systems. They are offering rebates of up to $5,000 on eligible grid-connected solar panels and up to an additional $5,000 for battery storage systems to qualifying residential customers.

The takeaway

Coast Essential Construction approaches whole-home sustainable renovations as more than just a technical exercise. Deep energy retrofits and embodied carbon reduction have become both an ethical and environmental imperative. They provide long-term value, enhance quality of life, and create a legacy of responsible stewardship that will benefit future generations.