I live in the City How Expensive is a Net Zero Retrofit?

Net Zero Retrofits can significantly reduce the lifetime costs related to energy supplied to the home. The following graphs and narratives show the relative sizes of the costs and Green House Gas (GHG) emissions for various common fuels used in the city. We have used a typical 2,000 Sqaure foot home as the basis for this illustration. We think that you'll conclude that Net Zero is a better way to power your home.

First we note that there are three main routes of energy consumption in a typical house.

  1. Space Heating

  2. Domestic Hot Water Heating

  3. Electricity for lighting, communications, Air Conditioning (AC), refrigeration, ventilation, etc.

 And that these have a different typical energy, cost and GHG impact. A Careful analysis of the cost and GHG impacts of each of these illustrates the advantage of Net Zero Power in each of these energy uses.

The typical energy mix of a 2,000 square foot house in populated Canada (i.e. not the far north) is about 65% of the energy is consumed by producing space heat, 15% by producing Domestic Hot Water (DHW) and 15% by electricity (lights, computers, outlets, refrigerator, air conditioning, etc.). This is by energy usage not cost. Costs are dependent on the fuel type supplied to the house for the 3 listed functions. So if you want to make the most energy and GHG emissions impact tackle your space heating consumption. See below.

Space Heating Costs and GHG Emissions

These are the typical space heating costs of a Net Zero Retrofit for a house in the city over the 20 year life of a heat pump or furnace or boiler. Houses in the city have access to Natural Gas (NG) fuel. NG is significantly cheaper than fuel oil, propane or electric resistance heating for space heating. So we haven't included fuel oil, propane or electric resistance heating in this analysis. The lighter orange colour portion of the cost bars (top portion) are the capital (upfront) cost portion of the costs while the lower darker colours are the costs for the energy used over a 20 space heating appliance life.

Domestic Hot Water Costs and GHG Emissions

Domestic Hot Water has the next largest impact on a house's GHG emissions. This graph shows significant  GHG reductions by changing the DHW system to an electrically powered heat pump with solar power electricity to offset the related electrical energy consumption. Note there is little cost difference in a DHW HP supplied with or without solar power and a small difference in the GHG emissions. Not shown in these graphs are the fact that if the space heating is moved off NG then the DHW should also be moved off to eliminate the signficant NG meter costs (approximately $4,500 over the life of the DHW heater). The DHW HP with solar power used to offset it's electricity consumption is the Net Zero option in this case.

Electricity Costs and GHG Emissions

Electricity has the least significant impact on a house's GHG emissions. This graph shows significant costs savings and GHG reductions by changing the electric supply from the utility supplied electricity to solar power electricity which offsets the related electrical energy consumption.

Once one determines that Net Zero is the best decision for energy to power a home, they typically upgrade their electrical supply at the first opportunity and their space or DHW supply to the Net Zero options when their heating appliance (furnace, boiler DHW heater) has to be retired.

See our fee webpage to discover the costs for Net Zero and/or fuel transition planning.

© 2020 by the Building Science Trust inc. Design by Ben