Heating load in Whitehorse

A home in Whitehorse has to be heated against a design temperature of −37.3 °C. That figure is measured, not modelled: it is the 1st percentile of daily minimum temperature over 28 years at Whitehorse Intl / Erik Nielsen Intl, 1 km away.

Design temperature −37.3 °C

Heating degree days 5,634

Coldest month Jan

Coldest night on record −47.0 °C

How many kilowatts

Heating power needed at the design temperature, in kilowatts, for a detached house. Pick the row that matches the building.

Construction	Detached	Semi-detached	Terraced	Top-floor flat	Mid-floor flat	Ground-floor flat
Uninsulated, single glazed	36.9 kW	32.4 kW	28.7 kW	31.5 kW	15.4 kW	18.8 kW
Unfilled cavity, early double glazing	25.0 kW	21.6 kW	18.8 kW	18.3 kW	11.1 kW	13.9 kW
Insulated to 1980s standards	14.3 kW	12.8 kW	11.7 kW	11.0 kW	7.9 kW	10.1 kW
Modern, roughly 1995-2010	8.8 kW	8.0 kW	7.4 kW	7.1 kW	5.4 kW	6.5 kW
Current building regulations	6.7 kW	6.2 kW	5.7 kW	5.5 kW	4.2 kW	5.1 kW
Passive house	4.0 kW	3.6 kW	3.3 kW	3.1 kW	2.1 kW	2.8 kW

Where the heat goes

For a 120 m2 detached house of this construction, at the design temperature.

Element	W	Share
Walls	4,707	33%
Roof	1,375	10%
Ground floor	928	7%
Windows	2,682	19%
Thermal bridges	788	6%
Ventilation and draughts	3,799	27%
Heating load	14,279	14.3 kW

Calculate it for your own home

The climate half of this is measured. The building half is yours to supply.

Monthly mean temperature

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
°C	−15.6	−11.9	−7.2	1.5	8.2	13.0	14.6	12.8	7.3	0.5	−8.5	−12.8

Where these numbers come from

Measured: the design temperature, the degree days and the monthly means. All of it from one station, Whitehorse Intl / Erik Nielsen Intl, over 28 complete years.
Assumed: everything about the building. The U-values are typical published figures for each construction era, not a survey of your house. Two houses of the same age and size can differ by a factor of two.
No credit is taken for sunshine or for the heat given off by people and appliances. That is the EN 12831 convention, because the design condition is a still, dark night.
This is space heating only. Domestic hot water is a separate load.
This is a calculation, not a survey. Before spending money, have the building assessed.