How many BTU for 2,800 sq ft?
Updated October 24, 2026
To heat 2,800 sq ft (260 m²) you need between 42,000 and 85,200 BTU/h depending on your city and insulation. Here is the calculation city by city, using the CSA F280 method.
Assumption: a 2,800 sq ft two-storey house with no heated basement, 8 ft ceilings, windows in proportion to floor area.
Heating load by city and house age
| City | After 2010 | 1990 to 2010 | 1970 to 1990 | Before 1970 | Cooling* |
|---|---|---|---|---|---|
| Vancouver (-7 °C) | 42,000 | 42,000 | 42,000 | 45,700 | 19,500 |
| Toronto (-18 °C) | 42,000 | 42,000 | 47,400 | 63,100 | 22,700 |
| Halifax (-16 °C) | 42,000 | 42,000 | 45,000 | 59,900 | 18,600 |
| Montreal (-23 °C) | 42,000 | 42,000 | 53,300 | 71,000 | 21,100 |
| Quebec City (-26 °C) | 42,000 | 42,000 | 56,900 | 75,700 | 19,500 |
| Winnipeg (-31 °C) | 42,000 | 43,300 | 62,800 | 83,600 | 21,100 |
| Edmonton (-32 °C) | 42,000 | 44,100 | 64,000 | 85,200 | 18,600 |
* Cooling for a 1990–2010 house, at the city’s summer design temperature.
Which Kanartic system for 2,800 sq ft?
Newer house in Toronto
Z-PRO 36,000 · 2 zones + ZERO 12,000 wall unitfrom $7,674 · DIY
Covers 100% of the heating load at -18 °C
See on kanartic.ca1990–2010 house in Montreal
Z-PRO 36,000 · 2 zones + ZERO 12,000 wall unitfrom $7,674 · DIY
Covers 100% of the heating load at -23 °C
See on kanartic.caPre-1970 house in Edmonton
Z-PRO 36,000 · 2 zones + ZERO 24,000 wall unitfrom $8,974 · DIY
Covers 70% of the heating load at -32 °C
See on kanartic.caWhat about 25 BTU per square foot?
The rule of thumb would give 70,000 BTU/h for 2,800 sq ft. The component calculation gives 42,000 to 85,200 BTU/h: depending on the house and climate, the rule is off by −18% to +67%.
Frequently asked questions
Is a 12,000 BTU heat pump enough for 2,800 sq ft?
In Montreal, for a 1990–2010 house, a 12,000 BTU unit covers 29% of the load at -23 °C; for a pre-1970 house, 17%. So you need a bigger unit or backup heat.
How many BTU to cool 2,800 sq ft?
Between 18,600 and 22,700 BTU/h for a 1990–2010 house, depending on the city. In Canada, heating sets heat pump size, not cooling.
Wall unit or multi-zone for 2,800 sq ft?
At this size, a multi-zone puts one indoor unit per floor or large room, connected to a single outdoor unit.
Other floor areas
2,200 sq ft2,400 sq ft2,600 sq ft3,000 sq ftAll
How many BTU for my house?Why not to oversizeHeat pump costBy room