The only hard number available for Yukon comes from a single weather station: Whitehorse A, at roughly 6,584 heating degree days a year, sits in climate zone 7b under Natural Resources Canada’s system. That zone calls for a recommended minimum of R-80 in the roof or ceiling, R-40 in walls, R-50 in floors over unheated spaces, and R-30 in basement walls. But Whitehorse is one station in a territory the size of Spain, and colder communities further north or at higher elevation may sit in a different zone entirely.
Which climate zone Yukon is in
Natural Resources Canada doesn’t zone the country by province or territory boundary. It zones by heating degree days, a running tally of how many degrees below 18°C the outside air sits, added up over a full year. The Whitehorse A station logs about 6,584 of them annually, which lands it in zone 7b under NRCan’s Table 2-1. That table sets the thresholds plainly: zone 4 is under 3,000 heating degree days, zone 5 runs 3,000 to 3,999, zone 6 runs 4,000 to 4,999, zone 7a runs 5,000 to 5,999, zone 7b runs 6,000 to 6,999, and zone 8 is anything over 7,000.
| NRCan zone | Annual heating degree-days (below 18°C) |
|---|---|
| Zone 4 | Under 3,000 |
| Zone 5 | 3,000–3,999 |
| Zone 6 | 4,000–4,999 |
| Zone 7a | 5,000–5,999 |
| Zone 7b | 6,000–6,999 |
| Zone 8 | Over 7,000 |
This is different from the letter system used south of the border, where a number is paired with A, B, or C to mark a moist, dry, or marine climate. NRCan’s system doesn’t work that way. The 7a/7b split, and zone 8 above it, are just finer cuts of degree-day count, nothing to do with humidity. So a Yukon reader comparing notes with a cousin in Montana or Alaska needs to remember these are two separate scales, counted on two separate Temperature bases, and a “zone 7” in one system says nothing about a “zone 7” in the other.
The 6,584 figure is specific to Whitehorse. It is not a territory-wide average, and Yukon is not a place where one station can stand in for the rest. Communities further north, like Dawson City or Old Crow, and places at higher elevation, likely rack up more heating degree days than Whitehorse does, which could put them in zone 8 rather than 7b. Before buying insulation, check the heating degree-day total for your own municipality against NRCan’s table, rather than assuming the capital’s number applies to your address.
The insulation levels that apply here
For zone 7b, the specific zone Whitehorse sits in, NRCan’s Table 2-1 lists recommended minimum nominal insulating values for four assemblies. Roof or ceiling: RSI 14.1, which is R-80. Walls: RSI 7.1, or R-40. Floor over an unheated space: RSI 8.8, or R-50. Basement walls: RSI 5.3, or R-30.
| Assembly | RSI (recommended minimum) | R-value |
|---|---|---|
| Roof or ceiling | 14.1 | 80 |
| Walls | 7.1 | 40 |
| Floor over unheated space | 8.8 | 50 |
| Basement walls | 5.3 | 30 |
Canada labels insulation performance in RSI, the metric measure, and prints the R-value alongside it because that’s the number most homeowners recognize from product packaging. Both figures describe the same thing, just in different units, and neither should be quietly dropped when you’re pricing material.
These are recommended minimums, not a code requirement handed down from Ottawa. Building code in Yukon is set at the territorial and municipal level, and it’s allowed to ask for more than NRCan’s table suggests. Treat this table as a floor to check your plans against, not a ceiling to stop at.
It’s also worth being precise about what these four numbers represent. They are not four attic values, or four wall values. Each one covers a different part of the building, roof, wall, floor, basement, and swapping them or averaging them across a house defeats the purpose of having a table broken out by assembly in the first place. And all four are the figures for zone 7b specifically, the zone the Whitehorse reference station falls into. A community further north sitting in zone 8 would need higher values across the board, but NRCan’s own numbers for that colder zone aren’t part of the fact set here, so don’t estimate them by extrapolating upward from this table. Check the zone for your own location first.
Sealing comes before insulating
U.S. ENERGY STAR treats air sealing and insulation as two parts of the same project, and its own project guidance puts attic air sealing ahead of attic insulation, not after it. The logic holds regardless of border: insulation slows heat moving through a material, but it does nothing to stop air moving around it. A bag of blown-in fiberglass laid over a gap around a wiring penetration or a plumbing stack doesn’t close that gap. It just buries it, which makes the leak harder to find on the next inspection, not less real.
The practical order of work follows from that:
- Seal the attic first, targeting penetrations, top plates, and chimney or plumbing chases
- Add or top up attic insulation once the leaks are closed
- Seal and insulate the rim joist, an area routinely skipped in older builds
- Address the floor over any unheated space or Crawlspace
- Move to walls last, since they’re the most disruptive and costly assembly to open up
Note that the published savings estimate from ENERGY STAR covers sealing and insulating together as one combined project. There isn’t a separate figure for sealing alone, so resist the urge to attach a percentage to that first step in isolation. It matters, but its value shows up in the combined number, not on its own.
The mechanics of each step, how to find attic bypasses, what rim joist sealing actually involves, are covered in the national insulation guides on this site rather than repeated here.
What the winter here actually asks for
Heating degree days measure demand, not a temperature you’d read off a thermometer. Whitehorse’s roughly 6,584 a year is a running total of how much heating a building has to supply over twelve months, and it’s the figure that turns climate into a fuel bill. Roughly speaking, double the degree days and you’re looking at something like double the heating energy for the same house, which is the whole reason the zone system is built around this number rather than an average January temperature.
What Yukon homes actually heat with matters just as much as the demand number. A 2012 Statistics Canada survey covering the three territories together, not Yukon alone, found hot-air furnaces powering 58% of dwellings, electric heating including baseboards at 18%, and heating stoves including wood stoves at 16%. Figures for steam or hot-water furnaces and for “other equipment” weren’t reported in that survey, which is not the same as zero, it means the estimate was suppressed rather than measured at nothing. And this data is from 2012. Heating stock moves over a decade and a half, heat pumps in particular have gained ground since, so treat this as a snapshot of where things stood then, not a current census.
That hot-air furnace share matters for where insulation dollars go first. A home heated by ducted forced air commonly runs those ducts through an attic or crawlspace that isn’t part of the conditioned envelope. Insulating the ceiling below a leaky, uninsulated duct run doesn’t fix the loss happening inside that duct run itself. Priorities for a Yukon home built around this reality:
- Seal and insulate the attic before anything else, since it’s both the biggest heat-loss area and the cheapest to reach
- Check duct runs through unconditioned spaces if the home uses a hot-air furnace, sealing joints and adding duct insulation where ducts pass through attics or crawlspaces
- Address the rim joist and floor over any unheated crawlspace, given the R-50 minimum recommended for that assembly in this zone
- Move to wall insulation last, once the above are handled
The duct guides on this site cover sealing and insulating ductwork in unconditioned spaces in more depth, and they’re the natural next stop for a furnace-heated home.
What the work is worth
U.S. ENERGY STAR puts a number on the combined project: “EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces, and accessible basement rim joists.” Both percentages matter, and so does what each one is measured against, 15% of heating and cooling costs specifically, or 11% of total energy costs, a different and larger denominator that pulls in electricity for lighting, appliances, and everything else running through the meter.
These are averages built from energy modeling of a typical existing U.S. home, not a measurement of any particular Yukon house and not a guarantee for one. The modeling also names exactly where the work happened: attics, floors over crawl spaces, and accessible basement rim joists. It doesn’t extend to walls, windows, or doors, so resist stretching this figure to cover a full envelope upgrade.
It’s also worth keeping this number separate from two others that sound similar but aren’t. ENERGY STAR’s own program landing page cites “up to a 10% savings on your annual energy bills” for the same category of work, an “up to” figure against yet another denominator. The U.S. Department of Energy’s frequently cited 10% figure is about a thermostat setback of 7 to 10°F held for eight hours a day, and has nothing to do with insulation at all. Three real numbers, three different claims, and the 15%/11% pairing above is the one that actually describes sealing and insulating an existing home.