Sustainable Home Renovations

At a residential level, your home and the energy used within it have a big impact on greenhouse gas emissions. Buildings are one of the largest sources of emissions; particularly in Canada, where we use vast amounts of energy to regulate indoor air temperature in response to our cool outdoor air temperature. For many people, this energy is produced using fossil fuels, like oil or natural gas, hence the resulting greenhouse gas emissions are substantial.

Another problem that arises from using large amounts of energy is one of cost. Continually supplying your home with heat energy is expensive, particularly when much of that heat escapes outside and is wasted. Renovating your home to improve its energy efficiency and make it more sustainable is an excellent method to save money over time while also reducing your carbon footprint. Conserving the energy we use to operate our houses from day-to-day is one of the most cost-effective actions we can take as individuals to improve our environmental impact and mitigate the effects of climate change.

Before undertaking a major home renovation to make your house or building more sustainable, be sure to use the Canadian Mortgage and Housing Corporation’s about your house fact sheets to gather information and help plan out your project. Improving the energy efficiency of your home with renovations is easier than you think. Unless you constantly monitor your energy usage and heating bills, you probably aren’t even aware of how much you are using and how much is being wasted.

Reduce Energy Demand

Most of the heat wasted through the daily operation of a house is lost as heat transfers from a warm area to a cold area. For much of the year, the warm area in this example is the inside of your house, while the cold area is outside. In inefficient houses, this heat energy flows freely from inside to outside. This is what causes the home’s energy demand to be so high. If your furnace is tasked with keeping the house at a specific temperature, it will need to operate constantly in order to keep up with the heat that is lost through the building envelope.

Renovating your home to upgrade the building envelope will yield energy savings by significantly restricting this flow of heat from the inside to the outside. There are a variety of ways to do this, but it is typically done by increasing the insulation (R-value) of the envelope and by restricting drafts and air leakage. Intuitively, this makes sense, as you’re reducing heat flowing across the barrier and restricting hot air from flowing through holes around the barrier. Logically, this means that more heat is trapped inside the barrier (the building envelope). If more heat is trapped inside the barrier than the house will stay at a more consistent temperature, your heating system will not need to work as hard, and you will save energy, money, and the environment.

You can learn more about renovating for energy savings based on the archetype of your home from the CMHC website. If you’re looking for ways to reduce the energy demand in your home, we recommend the energy conservation section of our website as a good place to start.

Decarbonizing Your Heat Energy Supply

Aside from reducing the energy demand required to heat your home, you can also reduce your house’s environmental footprint by supplementing its energy supply with clean, renewable energy sources. Here in BC, many of us are lucky in that BC Hydro uses over 95% renewable hydropower to generate our electricity. This means that actions like turning on a light or cooking something in the microwave do not emit many fossil fuels. Homeowners can take advantage of BC's clean electricity supply by replacing their oil or gas furnace with an electric air or ground source heat pump. Using electricity to control the temperature of your home is much more sustainable than using a combustion furnace, as it does not require greenhouse gas emitting fossil fuels to produce heat.

Electric heat pumps are also much more efficient than conventional furnaces. This is because furnaces use energy to create heat by raising the temperature of ambient air, which is an energy intensive process. Heat pumps function by extracting heat energy out of the exterior air and transporting it into the home. Conceptually, this process is physically similar to the way your refrigerator cools its interior to preserve your food, only the heat energy is flowing in the opposite direction.

By moving heat energy from the ambient air outside the building envelop instead of trying to create it, heat pumps are able to complete the same job as furnaces using much less energy. A high-efficiency oil furnace might convert 95 or 98% of the energy it uses into heat, but a well-maintained heat pump is capable of converting 300 to 400% of its energy. Not only will you be using a third of the energy to heat your house, but it will also be supplied by clean electricity! While the additional electricity demand will have some impact on your monthly bill, the difference is likely less than the fuel costs for supplying your old furnace.

Cost savings can also be gained in the long term by installing a renewable energy system to reduce the amount of electricity you draw from the grid. Rooftop photovoltaic panels are a common method of renewable energy generation. While the capital (initial) costs of such a renovation are substantial, the system will pay back the costs over time. This payback occurs through reductions in your bill, compensation for generating energy for the grid, and reduced roof maintenance and cooling demand, as solar panels prevent your roof from absorbing heat in the summer, which reduces degradation over time.

If you are looking to complete energy renovations on your house to make it more sustainable, you might find an energy evaluation helpful. The evaluation will identify where the most significant energy losses are occurring, and provide recommendations on how to address the issues. Seeking help from energy efficiency specialists will also help you identify potential projects that will conserve energy and save money over time. Once your home has been upgraded to become more energy efficient, labeling it as energy efficient will prove that it is a high-performance home, which raises your property value.

Other Sustainable Renovations

Beyond upgrading your home to improve its energy efficiency and decarbonize the energy supply, other sustainable renovations can also improve the performance of your home, which protects the environment and saves you money. Installing efficient water fixtures like aerators and low-flow shower heads will conserve huge amounts of water and cut down on energy costs, as using less water reduces the energy demand for hot water heating. Low-flow toilets are a particularly effective way to conserve water, as they can use 20-25% as much water per flush as conventional toilets. This can save dozens of litres of water, per toilet, per day.

There are many other methods to make your home more sustainable, many of which are described on the green building page. Reduce water use in your home, optimize irrigation in your yard to reduce water use outside, install an HVAC unit to improve indoor air quality and comfort, or install a green roof and permeable pavement to improve stormwater management and reduce pollution. Improving the energy efficiency and reducing the environmental impact of our built environment is a tremendously important task for developing a strong, sustainable society. Residential buildings and the people who live in them are an essential piece of the sustainable development puzzle. As a city we need everyone to do what they can to help reduce our environmental impact and prepare for the sustainability challenges we will face in the coming decades.

Additional Green Renovation Resources