Ontario · area guide · 21 communities · checked October 8, 2026

Home energy audits, radon and well water testing in York Region

The six towns and townships on this page are home to 309,475 people (2021 Census), and 11% of their houses were built before 1961. This guide covers 21 communities, from Newmarket, Aurora, Stouffville, Georgina and King to the smallest hamlets, with the local numbers that shape an energy audit or a home health test.

Energy audits in York Region → All 21 communities
A Victorian red-brick semi-detached house with a front porch in autumn

Population (2021)

309,475

Communities listed

21

Houses built before 1961

11%

Heating degree-days

4,243

King Smoke Tree

How York Region is built

York Region's houses by when they were built Ten house shapes, one for each tenth of York Region's 96,970 houses. Before 1961: 11%, 1961–1990: 34%, 1991–2000: 15%, 2001 or later: 40%. Older houses glow hotter.
  • Before 1961 11%
  • 1961–1990 34%
  • 1991–2000 15%
  • 2001 or later 40%
Each house stands for one in ten of York Region's 96,970 houses (single-detached, semi-detached, row, duplex and mobile homes), drawn by when it was built. The glow shows the usual pattern: older houses tend to be leakier and less insulated. More snow in the drawing means more heating degree-days: a longer, colder heating season. Sources: Statistics Canada 2021 Census (table 98-10-0233-01), Environment and Climate Change Canada 1981–2010 climate normals (King Smoke Tree) and the National Building Code 2020 January design temperature for Newmarket.

This page covers the York Region towns and townships we don't have separate city pages for: King, East Gwillimbury, Georgina, Whitchurch-Stouffville, Newmarket and Aurora. Vaughan, Markham and Richmond Hill have their own pages, which also cover their hamlets.

Great Lakes–St. Lawrence Southern Ontario and southern Quebec

York Region’s climate: Great Lakes–St. Lawrence

Cold winters and hot, humid summers: seal the attic, dry the basement, plan cooling.

This region has real winters and hot, humid summers, so bills come from both heating and cooling. Natural gas heats most Ontario homes, while most Quebec homes use low-cost electricity. An EnerGuide evaluation here should cover air sealing and the attic, cooling and dehumidification, and keeping the basement dry before insulating it.

  1. Seal air leaks and top up the attic

    Air sealing is still the first retrofit. In the snowier Ottawa–Montreal–Sherbrooke belt, a leaky, under-insulated attic also causes ice dams.

  2. Right-size cooling to control humidity

    In humid summers, an oversized air conditioner or heat pump cools quickly but shuts off before removing moisture, leaving rooms clammy. A heat pump replacing the air conditioner also covers much of the heating.

  3. Keep the basement dry before insulating

    Basements can be about 20% of heat loss, but insulating a damp basement from the inside can rot the new wall. Flash floods have hit Toronto and Montreal repeatedly.

When to book: Book the evaluation in winter (December to February) for clear thermal scans, and start a 3-month radon test in fall. Check the basement after spring thaw or heavy rain, and line up cooling work before summer.

Everything homes in Richmond Hill need →

Sources for this climate guide · checked October 26, 2026

Six local guides for York Region

Energy audits and heat pump sizing

An energy advisor’s kit on a front-hall bench: infrared camera, pressure gauge with tubing, tape measure, headlamp and a floor sketch

Home energy audits

27 registered organizations
A kitchen table with a house floor plan, a laser measure, a tape measure and a laptop showing the plan

Heat loss calculations

Design temp −20°C to −22°C

Home health and safety

A small digital radon monitor on a bookshelf in a finished basement family room

Radon testing and long-term monitoring

0% above guideline (2012)
A moisture meter pressed into water-stained basement drywall, an air-sampling pump on a tripod nearby

Mould and indoor air quality testing

45% built before 1991
Filling a water-sample bottle at a farmhouse kitchen tap with the aerator removed, snowy fields and a barn outside

Well water testing

Free bacteria tests
A Victorian red-brick semi-detached house with a front porch in autumn

Wood-burning appliance inspections (WETT)

Chimney inspection every 12 months

York Region at a glance

People and homes

309,475 people and 111,229 private dwellings in 2021, up 10.8% in population since 2016.

Housing

Of the 96,970 houses in York Region (single-detached, semi-detached, row houses, duplexes and mobile homes), 11% were built before 1961 and 45% before 1991, according to the 2021 Census. The typical house dates from 1991–1995.

Climate

Environment and Climate Change Canada's 1981–2010 climate normal at King Smoke Tree (11.9 km from the middle of the area) is 4,243 heating degree-days a year, with a January mean of −7.4°C. The building code's 2.5% January design temperatures for the area run from −20°C to −22°C.

Radon

In Health Canada’s 2012 survey, none of the 95 homes tested in the York Regional Health Unit were above the guideline, a small sample that doesn't rule radon out. The larger 2024 Cross-Canada survey reports 12.4% (1 in 8) of homes at or above the guideline for Ontario as a whole.

Wells

Free bacteria testing for owners of private drinking-water wells, analyzed by Public Health Ontario for total coliforms and E. coli. Pick up bottles weekdays from 8:30 a.m. to 4:30 p.m. and drop samples off Monday to Thursday before each site's cut-off: in Georgina at 20849 Dalton Road, Sutton (10 a.m.), 24262 Woodbine Avenue, Keswick (11 a.m.) and the Georgina Civic Centre, 26557 Civic Centre Road (10 a.m.); in Newmarket at 17150 Yonge Street (10 a.m.); in Richmond Hill at 50 High Tech Road (11 a.m.); in Vaughan at 9060 Jane Street (11 a.m.); and in Unionville at 4261 Highway 7 (11 a.m.). The Public Health Ontario lab at 81 Resources Road in Etobicoke takes drop-offs only, weekdays 8 a.m. to 2 p.m.

Energy advisors

NRCan's list (checked October 8, 2026) shows 27 service organizations registered for postal codes in Newmarket, Aurora, Stouffville, Keswick, Holland Landing and King City. Confirm they travel to your community.

Heating

Province-wide, 58% of Ontario households heat mainly with natural gas, 18% with electricity, 4% with propane and 1% each with oil and wood (Statistics Canada, 2023); there's no published breakdown for this area alone.

Every community in York Region

Grouped by municipality, with 2021 Census populations. Names come from Natural Resources Canada's geographical names database and Statistics Canada's population centres.

  • Town of Newmarket 87,942
  • Town of Aurora 62,057
  • Town of Whitchurch-Stouffville 49,864Ballantrae, Gormley, Stouffville
  • Town of Georgina 47,642Elmhurst Beach, Jacksons Point, Keswick, Pefferlaw, Sutton
  • Town of East Gwillimbury 34,637Holland Landing, Mount Albert, Queensville, River Drive Park
  • Township of King 27,333King City, Nobleton, Schomberg

Covered on city pages

  • Vaughan 323,103Vaughan's page covers Kleinburg, Maple, Concord and Woodbridge.
  • Markham 338,503Markham's page covers Unionville and Locust Hill.
  • Richmond Hill 202,022Richmond Hill has its own pages.

Who does the work in York Region

Rebates and financing for York Region homes

Provincial · needs an evaluation Home Renovation Savings — Home Energy Assessment path Up to $10,000 per home ($5,000 if heated with Enbridge gas), including $600 back on your two assessments, for insulation, windows, air sealing and more — if the follow-up assessment is done by December 31, 2026 Open · deadline Provincial Home Renovation Savings — direct rebates (no assessment) Heat pumps up to $7,500 ($12,000 ground-source), solar with battery up to $10,000, plus attic, thermostat and appliance rebates — no assessment needed Open Federal National Heat Pump Rebate Announced October 8, 2026 and opening early 2027: up to $10,000 below the median income, $2,000 for other eligible homeowners Announced · opens 2027 Federal CMHC Eco Improvement premium refund A 25% energy-efficiency rebate on your CMHC mortgage insurance premium after $20,000 of energy renovations Open

Nearby city pages and guides

Richmond HillMarkhamVaughan York Region advisor directoryYork Region guide What a home energy audit involvesThe CSA F280 heat-loss calculationThe radon testing guideThe mould and indoor air quality guideThe well water guideThe wood-burning inspection guide All area guides →

Sources

Checked October 8, 2026.

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