Basement heat pump: does it pay off? (Québec)
Step 1: quick heat-loss estimate →Step 2, final validation: full heat-loss calculator. Estimate only.
Does a basement heat pump pay off?
Site calculation for an 800 sq ft basement in Montréal and a wall-mounted heat pump at $3,000–$6,000: with uninsulated concrete walls heated by baseboards, savings are about $360 to $630 a year, a simple payback of 4.8 to 16.8 years. If the walls are already insulated (about R-12), savings drop to $100 to $220 a year and simple payback lengthens: 13.9 to 62.9 years. With heating oil, payback is shorter: 1.2 to 4.1 years for the uninsulated basement.
Estimate only. Method: basement heat loss (engine of the full calculator) at 19 °C, internal gains deducted, degree-days, capped by NRCan’s BASECALC reference; 57 to 82% supplied by the heat pump; savings = heat supplied × cost difference per kWh of heat; simple payback = (installed cost − rebate) ÷ savings (method). No savings are guaranteed; compare with your written quotes. For the final choice, ask your installer for a room-by-room load calculation (for example to the CSA F280 standard).
Optional: request up to 2 quotes from RBQ-licensed installers.
How much does a heat pump save in an 800 sq ft basement?
Results of the calculator above, as ranges (need rounded to 100 kWh, amounts to $10). A negative net means the savings do not repay the net cost within 15 years.
| Basement walls | Current heating | Heating need (kWh/yr) | Annual savings | Simple payback (years) | 15-year net |
|---|---|---|---|---|---|
| Uninsulated (concrete) | Electric baseboard heaters | 10,800–13,200 | $360 to $630 | 4.8–16.8 | −$640 to $6,380 |
| Uninsulated (concrete) | Heating oil | 10,800–13,200 | $1,460 to $2,570 | 1.2–4.1 | $15,970 to $35,480 |
| Insulated about R-12 | Electric baseboard heaters | 2,900–4,600 | $100 to $220 | 13.9–62.9 | −$4,570 to $240 |
| Insulated about R-12 | Heating oil | 2,900–4,600 | $390 to $890 | 3.4–15.3 | −$130 to $10,300 |
| Insulated to current Code | Electric baseboard heaters | 2,200–3,500 | $70 to $170 | 17.8–83.5 | −$4,920 to −$470 |
| Insulated to current Code | Heating oil | 2,200–3,500 | $290 to $690 | 4.3–20.4 | −$1,580 to $7,360 |
When does it pay off best?
- When the basement is heated with oil: each kWh of oil heat costs more than baseboard heat, at the prices below.
- When the walls are uninsulated: the heating need is larger, so are the savings. Insulating reduces the need but lengthens the heat pump’s payback.
- When the basement is not heated today, there are no savings to calculate: the heat pump adds comfort, not savings.
How is it calculated?
- Basement design heat loss with the engine of the heat-loss calculator (above- and below-grade walls, windows, slab, air leakage), as a low and a high bound.
- Annual need: the same engine, but at 19 °C (basement temperature of the EnerGuide standard conditions), with 3 kWh per day of internal gains released in the basement. Variable-base degree-day method: 19 °C minus gains ÷ loss coefficient.
- Safeguard: the loss through the walls and slab never exceeds the reference value of NRCan’s BASECALC software for the same insulation (2007 CMHC study), adjusted to the floor area and the location’s degree-days.
- The heat pump supplies 57 to 82% of that need; the rest stays with the current heating.
- Savings = heat supplied by the heat pump × (cost of one kWh of current heat − cost of one kWh of heat pump heat).
- Simple payback = (installed cost − rebate) ÷ annual savings. 15-year net = savings × 15 − (installed cost − rebate), at constant prices, before taxes, excluding maintenance and cooling.
| Parameter | Value | Source |
|---|---|---|
| Heating degree-days | by location (Montréal 4,363) | Climate normals 1981–2010,Environment and Climate Change Canada; use to estimate annual heating need: NRCan, Keeping the Heat In (2012). Other bases (0, 5, 10 and 15 °C): shape of the Montréal-Trudeau curve (ECCC, 1981–2010 normals, 3,559.55 °C·d below 15 °C), applied to every location: site assumption. |
| Basement temperature and gains (annual need) | 19 °C; 20 kWh/day × 0.15 = 3 kWh/day | NRCan HOT2000 common settings, similar to the EnerGuide standard operating conditions: HOT2000 guide for the NBC 9.36.5 performance path (version 1.00, March 2013), section 4.2. The design loss shown stays at 22 °C (sizing temperature in the same guide). |
| BASECALC reference (walls and slab, Ottawa/Hull) | uninsulated 33.3 and 62.1 GJ/yr; interior R-12 11.7 and 20.4 GJ/yr; interior R-20 9.8 and 17.1 GJ/yr (672 and 1,536 sq ft) | Kesik, University of Toronto, for CMHC (11th Canadian Conference on Building Science and Technology, 2007), tables 5 and 6, simulations by BASECALC (CANMET, NRCan). Fit by perimeter and area, and “Code” compared with R-20: site estimate. |
| Design temperature | January 2.5% (Montréal −23 °C) | NBC 2020, Table C-2. Beauce: not listed, not offered. |
| Typical basement | square plan, 2.3 m high, 25% above grade, windows = 2% of floor, clear double glazing | Defaults of the heat-loss calculator (site estimate); soil per Latta and Boileau (NRC, 1969) and Mitalas (NRC, 1983). |
| Insulation and airtightness | RSI 0.2–0.3 / 2.1 / 2.99; 5.3–7.7 / 3.1–4.4 / 2.2–3.1 ACH50 | Presets of the heat-loss calculator (RSI 2.99: Code requirement); pairing insulation ↔ airtightness: site estimate. |
| Share supplied by the heat pump | 57–82% | Figure 22 of the NRCan sizing guide (version 1.0, December 21, 2020), “Very-Cold” curve (figure 23: most of populated Québec), read by the site at a balance point of −6 °C (57%) and −15 °C (82%). Balance point of a wall unit sized for the basement: site assumption. |
| Heat pump seasonal efficiency | HSPF 7.1 → COP 2.08 | Low end of the range of products on the market (region 5: 7.1 to 13.2), NRCan; COP = HSPF ÷ 3.412, as in the cost analysis. |
| Electricity | 11.142¢/kWh | Rate D as of April 1, 2026, price above 40 kWh per day, before taxes: Hydro-Québec. |
| Heating oil | $2.4079/L; 38.2 MJ/L; 78% efficiency | Québec weighted average, week of October 19, 2026, before taxes: Régie de l’énergie; efficiency: regulatory minimum since 1998 (NRCan), as in the cost analysis. |
| Installed cost | $3,000 to $6,000 | Single-zone wall unit, BranchéQC (private platform, guide updated June 25, 2026). Not an average: compare your written quotes. |
Frequently asked questions
Why a range rather than one number?
Without measurements, the actual wall resistance, airtightness and the exact share of heating the heat pump will do are unknown. The calculation therefore combines the low bounds together, then the high bounds.
Why doesn’t the heat pump supply all the heating?
In very cold weather, an air-source heat pump’s capacity drops and backup heat takes over. On the NRCan guide’s “Very-Cold” curve, a heat pump that is sufficient down to −6 °C supplies about 57% of annual heating, and about 82% if it is sufficient down to −15 °C.
Are these heating needs realistic?
They are of the same order as Canadian references. An NRC test basement in Ottawa, insulated RSI 1.55, lost 23.3 GJ (about 6,500 kWh) in one year (measured); the calculation assigns about 17 GJ (4,700 kWh) of it to October through April. Source: Mitalas (NRC, 1983). According to Beausoleil-Morrison, Mitalas and Chin (NRCan and NRC, 1995), basements and slabs account for 10 to 40% of the heating energy of Canadian houses; NRCan (Keeping the Heat In, 2012) cites about 20%. An uninsulated basement heated all winter can sit at the top of these ranges.
Is cooling counted?
No. The calculation counts heating only. Cooling is an added comfort, with no savings counted here.
Is my data sent anywhere?
No. The calculation runs in your browser and nothing you enter is transmitted.
Sources
- NRCan, Air-Source Heat Pump Sizing and Selection Guide, version 1.0, December 21, 2020, step 6.
- NRCan, Keeping the Heat In, 2012 (heating degree-days; basement ≈ 20% of heat loss).
- NRCan, HOT2000 guide for the NBC 9.36.5 performance path, version 1.00, March 2013, section 4.2.
- Kesik, Cost Effective Levels of Thermal Insulation for Basements in Canadian Housing, CMHC, 2007, tables 5 and 6.
- Beausoleil-Morrison, Mitalas, Chin, Estimating Three-Dimensional Below-Grade Heat Losses from Houses Using Two-Dimensional Calculations, 1995 (BASECALC).
- Mitalas, Calculation of Basement Heat Loss, NRC, 1983, appendix A.
- ECCC, Canadian Climate Normals 1981–2010; Montréal-Trudeau degree-days below 0 to 18 °C: open data, accessed October 22, 2026.
- NRC, National Building Code of Canada 2020, Division B, Appendix C, Table C-2.
- Hydro-Québec, Electricity rates as of April 1, 2026.
- Régie de l’énergie, weekly heating oil price survey, week of October 19, 2026.
- NRCan, Heating and cooling with a heat pump.
- BranchéQC, heat pump installation cost in Québec, updated June 25, 2026.
See also: the cost analysis (whole house) · 2026 prices · the 2026–2027 rebates · all tools.