Keeping the heat in · worked examples · prices as of October 8, 2026
What upgrades really save: four houses, every number shown
Estimates only build confidence if you can see where they come from. Here are four typical Canadian houses run through the same model our planner and calculators use: local climate, today's local prices, and the physics of each upgrade, with nothing hidden. They are modelled examples, not customer stories.
Example 1 · Ottawa, Ontario
A 1970s two-storey in Ottawa, heated with gas
1,600 sq ft detached house built 1966–1980, mid-efficiency gas furnace (about 80%), gas tank water heater, older double-pane windows. The owners entered a $130 average monthly gas bill.
1. How much heat does it need?
| Step | Calculation | Result |
|---|---|---|
| Local climate | Ottawa: heating degree-days from NRCan's HOT2000 weather data (Ottawa International) | 4,354 degree-days |
| Typical heat need | 0.6 GJ/m² × 149 m² × (4,354 ÷ 4,200) | 92.5 GJ a year |
| Scaled to the bill | $130/month × 12 ÷ $0.478/m³ = 3,264 m³ of gas; 80% for heating × 37.5 MJ per m³ × 80% efficiency = 78.3 GJ | × 0.85 → 78.3 GJ |
| Heating cost today | 78.3 GJ ÷ 80% = 97.9 GJ bought ÷ 37.5 MJ per m³ = 2,611 m³ of gas × $0.478/m³ (average, taxes in) | $1,250 a year |
2. What each upgrade saves
| Upgrade | The physics | Heat saved | On the bill | Typical cost | Payback |
|---|---|---|---|---|---|
| Professional air sealing (20% less leakage) | NRCan: about 25% of heat loss is air leakage → 78.3 GJ × 25% × 20% × 0.75 | 2.9 GJ (4%) | 98 m³ of gas = $31/yr | $350–$1,500 | 11 years–49 years |
| Attic insulation, R-20 → R-60 | 74 m² of attic × (1/RSI 3.5 − 1/RSI 10.6) × 4,354 degree-days × 24 h × 0.75 | 3.4 GJ (4%) | 112 m³ of gas = $35/yr | $1,200–$1,960 | 34 years–56 years |
| Basement walls to R-20 (RSI 3.5) | 83 m² of basement wall × (1/RSI 0.7 − 1/RSI 3.5) × 4,354 × 24 h × 0.4 (the ground moderates temperatures) | 12.1 GJ (15%) | 402 m³ of gas = $125/yr | get quotes (no reliable published price) | — |
| Replace 15 windows (double glazing, clear (1970s–1990s) → ENERGY STAR) | 17.8 m² of glass × (U 2.86 − U 1.22) × 4,354 × 24 h × 0.75 | 7.0 GJ (9%) | 233 m³ of gas = $73/yr | $12,000–$18,000 | over 100 years–over 100 years |
Savings at the next-unit price of $0.314/m³ (no fixed charges), before rebates. All of them together: about 22.7 GJ (29% of heating, less than the 32% you get by adding them, because savings overlap), worth about $240 a year.
3. Heating it a different way (after those upgrades: 55.6 GJ a year)
| System | Seasonal efficiency | Cost a year (average prices) | Cost a year (next-unit prices) |
|---|---|---|---|
| Gas furnace, mid-efficiency (about 80%) (now) | 80% | $885 | $580 |
| Gas furnace, high-efficiency condensing (95%) | 95% | $745 | $490 |
| Cold-climate air-source heat pump | COP 2.2 | $1,250 | $995 |
Heat pump efficiencies are whole-season figures for Ottawa's climate, including backup heat on the coldest days (Dunsky for the Canadian Climate Institute; field studies in BC and Yukon), set on the low side.
4. Hot water for three people
225 litres a day heated from about 10 °C (cold water in Ottawa) to 55 °C = 15.5 GJ a year.
| Water heater | Cost a year |
|---|---|
| Gas tank (standard) (now) | $340 |
| Gas tankless | $225 |
| Heat pump water heater | $440 (includes $90 of extra space heating: it cools the room it sits in) |
What this house tells you
With Ontario gas at about 31 cents per cubic metre at the margin, insulation and air sealing save real energy but pay back slowly on the bill alone. Rebates, comfort and a cold basement that becomes usable are what make them worth doing; new windows are the slowest payback of all.
Run your own Ottawa numbers → · Compare heating systems in Ottawa →
Example 2 · Winnipeg, Manitoba
A 1950s bungalow in Winnipeg with electric baseboards
1,100 sq ft one-storey detached house built 1946–1965, electric baseboards, electric tank water heater, single-pane windows with storms. No bills entered, so this is the typical-house estimate.
1. How much heat does it need?
| Step | Calculation | Result |
|---|---|---|
| Local climate | Winnipeg: heating degree-days from NRCan's HOT2000 weather data (Winnipeg International) | 5,542 degree-days |
| Typical heat need | 0.7 GJ/m² × 102 m² × (5,542 ÷ 4,200) | 94.4 GJ a year |
| Scaled to the bill | No bill entered, so the typical figure stands | 94.4 GJ |
| Heating cost today | 94.4 GJ ÷ 100% = 94.4 GJ bought ÷ 3.6 MJ per kWh = 26,220 kWh × $0.126/kWh (average, taxes in) | $3,300 a year |
2. What each upgrade saves
| Upgrade | The physics | Heat saved | On the bill | Typical cost | Payback |
|---|---|---|---|---|---|
| Professional air sealing (20% less leakage) | NRCan: about 25% of heat loss is air leakage → 94.4 GJ × 25% × 20% × 0.75 | 3.5 GJ (4%) | 983 kWh = $105/yr | $350–$1,500 | 3.3 years–14 years |
| Attic insulation, R-12 → R-60 | 102 m² of attic × (1/RSI 2.1 − 1/RSI 10.6) × 5,542 degree-days × 24 h × 0.75 | 13.9 GJ (15%) | 3,859 kWh = $415/yr | $1,650–$2,700 | 4.0 years–6.5 years |
| Dense-pack the wall cavities, RSI 1.4 → RSI 2.1 | 86 m² of wall (less windows) × (1/RSI 1.4 − 1/RSI 2.1) × 5,542 × 24 h × 0.75 | 7.3 GJ (8%) | 2,041 kWh = $220/yr | get quotes (no reliable published price) | — |
Savings at the next-unit price of $0.107/kWh (no fixed charges), before rebates. All of them together: about 22.9 GJ (24% of heating, less than the 26% you get by adding them, because savings overlap), worth about $680 a year.
3. Heating it a different way (after those upgrades: 71.5 GJ a year)
| System | Seasonal efficiency | Cost a year (average prices) | Cost a year (next-unit prices) |
|---|---|---|---|
| Electric baseboards or electric furnace (100%) (now) | 100% | $2,500 | $2,120 |
| Cold-climate air-source heat pump | COP 2.0 | $1,250 | $1,060 |
| Ground-source (geothermal) heat pump | COP 2.8 | $895 | $760 |
Heat pump efficiencies are whole-season figures for Winnipeg's climate, including backup heat on the coldest days (Dunsky for the Canadian Climate Institute; field studies in BC and Yukon), set on the low side.
4. Hot water for three people
225 litres a day heated from about 6 °C (cold water in Winnipeg) to 55 °C = 16.7 GJ a year.
| Water heater | Cost a year |
|---|---|
| Electric tank (now) | $635 |
| Heat pump water heater | $480 (includes $215 of extra space heating: it cools the room it sits in) |
What this house tells you
Manitoba has some of Canada’s cheapest electricity, so even an all-electric house has modest bills. A cold-climate heat pump still cuts the heating bill by about half at Winnipeg’s seasonal efficiency, and topping up the attic pays back in roughly four to seven years before rebates.
Run your own Winnipeg numbers → · Compare heating systems in Winnipeg →
Example 3 · Halifax, Nova Scotia
A 1920s house in Halifax heated with oil
1,600 sq ft two-storey detached house built before 1946, oil furnace (about 78%), electric tank water heater, single-pane windows with storms. No bills entered.
1. How much heat does it need?
| Step | Calculation | Result |
|---|---|---|
| Local climate | Halifax: heating degree-days from NRCan's HOT2000 weather data (Shearwater) | 3,870 degree-days |
| Typical heat need | 1 GJ/m² × 149 m² × (3,870 ÷ 4,200) | 137 GJ a year |
| Scaled to the bill | No bill entered, so the typical figure stands | 137 GJ |
| Heating cost today | 137 GJ ÷ 78% = 176 GJ bought ÷ 38.2 MJ per L = 4,597 L of oil × $1.78/L (average, taxes in) | $8,180 a year |
2. What each upgrade saves
| Upgrade | The physics | Heat saved | On the bill | Typical cost | Payback |
|---|---|---|---|---|---|
| Professional air sealing (20% less leakage) | NRCan: about 25% of heat loss is air leakage → 137 GJ × 25% × 20% × 0.75 | 5.1 GJ (4%) | 172 L of oil = $305/yr | $350–$1,500 | 1.1 years–4.9 years |
| Attic insulation, R-12 → R-55 | 74 m² of attic × (1/RSI 2.1 − 1/RSI 9.7) × 3,870 degree-days × 24 h × 0.75 | 6.9 GJ (5%) | 231 L of oil = $410/yr | $1,200–$1,960 | 2.9 years–4.8 years |
| Dense-pack the wall cavities, RSI 0.7 → RSI 2.1 | 147 m² of wall (less windows) × (1/RSI 0.7 − 1/RSI 2.1) × 3,870 × 24 h × 0.75 | 35.0 GJ (26%) | 1,175 L of oil = $2,090/yr | get quotes (no reliable published price) | — |
| Replace 15 windows (single glazing with a storm window → ENERGY STAR) | 17.8 m² of glass × (U 2.90 − U 1.22) × 3,870 × 24 h × 0.75 | 7.5 GJ (5%) | 252 L of oil = $450/yr | $12,000–$18,000 | 27 years–40 years |
Savings at the next-unit price of $1.78/L (no fixed charges), before rebates. All of them together: about 48.9 GJ (36% of heating, less than the 40% you get by adding them, because savings overlap), worth about $2,920 a year.
3. Heating it a different way (after those upgrades: 88.1 GJ a year)
| System | Seasonal efficiency | Cost a year (average prices) | Cost a year (next-unit prices) |
|---|---|---|---|
| Oil furnace, mid-efficiency (about 78%) (now) | 78% | $5,260 | $5,260 |
| Cold-climate air-source heat pump | COP 2.5 | $2,170 | $1,970 |
Heat pump efficiencies are whole-season figures for Halifax's climate, including backup heat on the coldest days (Dunsky for the Canadian Climate Institute; field studies in BC and Yukon), set on the low side.
4. Hot water for three people
225 litres a day heated from about 10 °C (cold water in Halifax) to 55 °C = 15.4 GJ a year.
| Water heater | Cost a year |
|---|---|
| Electric tank (now) | $1,030 |
| Heat pump water heater | $765 (includes $335 of extra space heating: it cools the room it sits in) |
What this house tells you
Oil makes this the house where every upgrade pays fastest, even at the 12-month average price we use (recent months have been higher). Switching to a cold-climate heat pump saves about $3,000 a year, and air sealing and the attic pay back in roughly one to five years before rebates.
Run your own Halifax numbers → · Compare heating systems in Halifax →
Example 4 · Toronto, Ontario
A 2000s semi in Toronto that is already fairly efficient
1,600 sq ft semi-detached house built 1996–2010, high-efficiency gas furnace (95%), gas tank water heater, double-pane low-e windows. No bills entered.
1. How much heat does it need?
| Step | Calculation | Result |
|---|---|---|
| Local climate | Toronto: heating degree-days from NRCan's HOT2000 weather data (Toronto City Centre) | 3,559 degree-days |
| Typical heat need | 0.4 GJ/m² × 149 m² × (3,559 ÷ 4,200) × 0.9 (semi-detached) | 45.3 GJ a year |
| Scaled to the bill | No bill entered, so the typical figure stands | 45.3 GJ |
| Heating cost today | 45.3 GJ ÷ 95% = 47.7 GJ bought ÷ 37.5 MJ per m³ = 1,273 m³ of gas × $0.478/m³ (average, taxes in) | $610 a year |
2. What each upgrade saves
| Upgrade | The physics | Heat saved | On the bill | Typical cost | Payback |
|---|---|---|---|---|---|
| Thermostat schedule: 3 °C lower for 8 hours a night | NRCan: about 2% per 1 °C over 8 hours → 3 × 2% = 6% of 45.3 GJ | 2.7 GJ (6%) | 76 m³ of gas = $24/yr | about $0 with your thermostat | immediate |
| Professional air sealing (20% less leakage) | NRCan: about 25% of heat loss is air leakage → 45.3 GJ × 25% × 20% × 0.75 | 1.7 GJ (4%) | 48 m³ of gas = $15/yr | $350–$1,500 | 23 years–over 100 years |
| Attic insulation, R-40 → R-55 | 74 m² of attic × (1/RSI 7.0 − 1/RSI 9.7) × 3,559 degree-days × 24 h × 0.75 | 0.7 GJ (1%) | 19 m³ of gas = $6/yr | $1,200–$1,960 | over 100 years–over 100 years |
Savings at the next-unit price of $0.314/m³ (no fixed charges), before rebates. All of them together: about 4.9 GJ (11% of heating), worth about $43 a year.
3. Heating it a different way (after those upgrades: 40.4 GJ a year)
| System | Seasonal efficiency | Cost a year (average prices) | Cost a year (next-unit prices) |
|---|---|---|---|
| Gas furnace, high-efficiency condensing (95%) (now) | 95% | $540 | $355 |
| Cold-climate air-source heat pump | COP 2.5 | $845 | $645 |
Heat pump efficiencies are whole-season figures for Toronto's climate, including backup heat on the coldest days (Dunsky for the Canadian Climate Institute; field studies in BC and Yukon), set on the low side.
4. Hot water for three people
225 litres a day heated from about 13 °C (cold water in Toronto) to 55 °C = 14.5 GJ a year.
| Water heater | Cost a year |
|---|---|
| Gas tank (standard) (now) | $320 |
| Gas tankless | $215 |
| Heat pump water heater | $415 (includes $71 of extra space heating: it cools the room it sits in) |
What this house tells you
A newer house with a 95% furnace and cheap gas has little left to save on heating; a thermostat schedule is the best value. Here the case for a heat pump rests on replacing an aging air conditioner, comfort and emissions rather than the bill, and the numbers say so plainly.
Run your own Toronto numbers → · Compare heating systems in Toronto →
The method, and why it leans conservative
Heat need comes from NRCan's Comprehensive Energy Use Database: heating requirement per square metre of floor for each construction period, normalised to 4,200 degree-days and checked against NRCan's typical heating loads for Ottawa and Toronto houses. Your city's degree-days come from NRCan's HOT2000 weather data, the same data EnerGuide evaluations use.
Each upgrade's saving is calculated from its own physics: the change in insulation or window U-value times the area times the degree-days. We then multiply by 0.75 (0.4 for basement walls) because the sun, people and appliances already supply some free heat and real installations underperform their labels. Air sealing uses NRCan's rule that about a quarter of heat loss is air leakage, with a 20% reduction in leakage. Starting insulation levels by era are our assumptions (no Canadian survey table exists); the calculators let you change them.
Savings are valued at the price of your next unit of energy, without fixed monthly charges, which is lower than your average price. Costs are published installed-cost ranges (HomeStars, FurnacePrices.ca) where a reliable figure exists, and "get quotes" where it doesn't. Rebates aren't subtracted here because they depend on your province and program rules: the upgrade payback calculator applies the ones that are open.
Common questions
Are these real customers?
No. They are modelled examples: typical houses run through the same calculations our planner and calculators use, with local prices and climate data. We show every step so you can check the arithmetic, and the calculators let you replace any assumption with your own numbers.
Why are the savings smaller than some contractors quote?
We stay conservative on purpose. Savings are reduced by a factor of 0.75 (0.4 for basements) for free heat from the sun, people and appliances and for real-world installation, valued at the price of your next unit of energy without fixed charges, and no upgrade is credited with more than 35% of heating (60% for all of them together).
Why does a heat pump cost more to run than gas in some examples?
In Ontario, natural gas costs about 31 cents per cubic metre at the margin, and a cold-climate heat pump’s seasonal efficiency in a cold city is about 2 to 2.5. At those prices the running costs can come out close, or higher for the heat pump. Against oil, propane or electric baseboards the heat pump wins by a wide margin.
How do I get numbers for my own house?
Enter your bills in the planner or a calculator: we then scale every saving to how much heat your house actually uses. An EnerGuide evaluation replaces the estimates with measurements, including a blower door test.
Sources
- NRCan Comprehensive Energy Use Database 2023, Ontario residential Table 33 (heating requirement per floor area by vintage)
- NRCan, Heating with Gas (revised October 2012): Table 2 energy content, Table 3 efficiencies, Table 4 heating loads
- NRCan, HOT2000 Climate Map: heating degree-days and design temperatures for 403 locations
- NRCan, Keeping the Heat In, Section 9: Thermostats ("2 percent per 1 °C over eight hours"; "about 25 percent of heat loss can be due to air leakage")
- NRCan, Keeping the Heat In, Section 7: Walls ("about 20 percent of heat loss")
- NRCan, Keeping the Heat In, Section 8: Windows and doors
- Dunsky Energy + Climate for the Canadian Climate Institute, Heat Pumps Pay Off: technical report (2024)
- NRCan, Heating and cooling with a heat pump (modified 2025-12-24)
- HomeStars, Attic insulation cost (updated 21/08/2026)
- HomeStars, Window replacement cost (updated 21/08/2026)
- FurnacePrices.ca, Heat pump prices (updated September 1, 2026)
- Environment and Climate Change Canada, Canadian Climate Normals 1981–2010 (MSC GeoMet API)
- US DOE Energy Saver, Tankless or demand-type water heaters (24–34% / 8–14% claim)
- Energy prices: provincial utility tariffs, Hydro-Québec's comparison of electricity prices, and Statistics Canada table 18-10-0001-01 for heating oil, as listed on each city calculator page.
Prices and program details checked October 8, 2026.
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