How Grey County is built
- Before 1961 34%
- 1961–1990 36%
- 1991–2000 10%
- 2001 or later 20%
This page covers the nine member municipalities of the County of Grey, from Owen Sound and Meaford on Georgian Bay to Hanover, Durham and Dundalk inland.
Design temperatures across Grey County
The National Building Code of Canada 2020 says the 2.5% January design temperature is the value ordinarily used to design heating systems. Its climate table lists these Ontario locations in or next to Grey County:
| Location in the code’s table | January 2.5% design temperature | Heating degree-days |
|---|---|---|
| Owen Sound | −19°C | 4,030 |
| Markdale | −20°C | 4,500 |
| Durham | −20°C | 4,340 |
| Dundalk | −22°C | 4,700 |
| Hanover | −19°C | 4,300 |
Environment and Climate Change Canada's 1981–2010 climate normal at Thornbury Slama (27.4 km from the middle of the area) is 4,188 heating degree-days a year, with a January mean of −6.3°C.
What CSA F280-12 asks for
The code requires the heating capacity for a house to be worked out with CSA F280, using the code's own design temperatures, and its list of referenced documents names the 2012 edition, CSA F280-12. The calculation works out how much heat each room loses on the design day, from the house's actual walls, windows, ceiling insulation and air leakage.
At −19°C to −22°C, a cold-climate heat pump sized to the calculation can carry most of the season, and the number shows how much backup heat the coldest days need.
What the calculation needs from your house
Of the 36,295 houses in Grey County (single-detached, semi-detached, row houses, duplexes and mobile homes), 34% were built before 1961 and 69% before 1991, according to the 2021 Census. In an older or renovated house, the walls, windows and air leakage rarely match the original plans, so ask the designer to measure rather than assume. Have this ready:
- Room dimensions and ceiling heights, or a floor plan.
- Window and door sizes and types, room by room.
- Insulation levels in the attic, walls, basement and any floor over an unheated space.
- A blower door result from an EnerGuide evaluation, if you've had one.
- Where the ducts, radiators or baseboards run, so the heat can be delivered room by room.
What it costs
There's no standard published price for a standalone F280 calculation, so ask two or three providers for a written quote that names the deliverable: the room-by-room F280 report, not just an equipment size. Many energy advisors bundle it with an EnerGuide evaluation, which also gives the calculation measured air-leakage data instead of an assumption. Ask whether a rural travel fee applies. The CSA F280 heat-loss calculation explains the method and typical cost bands.
Communities we cover in Grey County
Every town, village and hamlet below is part of this page, grouped by municipality (2021 Census population).
- City of Owen Sound 21,612
- Municipality of West Grey 13,131Durham
- Municipality of Meaford 11,485
- Township of Georgian Bluffs 11,100
- Municipality of Grey Highlands 10,424Feversham, Flesherton, Kimberley, Markdale, Maxwell, Priceville
- Town of The Blue Mountains 9,390Clarksburg, Thornbury
- Township of Southgate 8,716Dundalk
- Town of Hanover 7,967
- Township of Chatsworth 7,080
NRCan-registered service organizations serving Grey County
NRCan's list of service organizations (checked October 8, 2026) shows 21 organizations registered for postal codes in Owen Sound, Meaford and Hanover (N4K, N4L, N4N). Registration means an organization lists those postal areas, not that it has an advisor in town: confirm they travel to your community, and ask about wait times and travel fees.
Only assessments from the seven HRSP-approved organizations qualify for the $600 Home Renovation Savings rebate and its assessment-path upgrade rebates; each listing below says whether it's one of them.
- Acacia Engineering HRSP-approved: No
- All Season Inspection HRSP-approved: No Profile
- AmeriSpec HRSP-approved: Yes Profile
- Capital Home Energy HRSP-approved: No
- Clean Energy Solutions HRSP-approved: No
- EnerQuality HRSP-approved: No
- EnerSolution HRSP-approved: No Profile
- EnviroCentre HRSP-approved: No
- Environment Network HRSP-approved: No Non-profit network Profile
- ER Energy Solutions HRSP-approved: No
- Green Canada Home Advisors HRSP-approved: No Profile
- Greenbrain HRSP-approved: Yes Profile
- Sensible Home Inspections HRSP-approved: No
- The Energuy HRSP-approved: Yes Profile
- Verdatech Energy Management and Consulting HRSP-approved: No
- Energy Werx HRSP-approved: Yes Profile
- EcoLogic Energy Advisors HRSP-approved: No
- Green Think HRSP-approved: No
Heat pump programs in Grey County
Heat loss calculations in Grey County: common questions
What design temperature is used for heat pump sizing in Owen Sound?
The National Building Code 2020's climate table gives −19°C for Owen Sound, −20°C for Markdale, −20°C for Durham, −22°C for Dundalk and −19°C for Hanover. Provincial codes can use their own climate tables, so ask which value the calculation uses.
What is CSA F280-12?
The 2012 edition of CSA F280, Determining the required capacity of residential space heating and cooling appliances. The National Building Code 2020 requires heating capacity for a house to be determined with it.
How much does a heat loss calculation cost?
There is no standard published price. Ask two or three providers for a written quote for the F280 report, and ask whether it costs less bundled with an EnerGuide evaluation and whether a travel fee applies.
Who does F280 calculations in Grey County?
Many of the 21 NRCan-registered organizations that list Owen Sound, Meaford and Hanover postal codes offer them, as do HVAC designers. Ask for the F280 report itself, not just an equipment size.