28 June 2026
June 2026 has been one for the record books. Temperatures across Greater Manchester and the rest of the UK have been well above average, and a lot of homeowners have been thinking about how their homes handle the heat. So it's a fair question: does hot weather actually affect your EPC rating?
No. Your EPC rating isn't affected by what the weather is doing on the day of the assessment. The calculation is based on the physical characteristics of the property, not the temperature outside. Whether I visit in January or the middle of a heatwave, the rating will be the same.
The EPC model uses standardised assumptions about occupancy and climate to calculate energy use. It doesn't change based on actual weather conditions, so there's no advantage or disadvantage to timing your assessment around the seasons.
While the EPC itself isn't affected, extreme heat has a way of exposing things that matter for energy efficiency. If your home turns into a greenhouse every time the sun comes out, that's telling you something about insulation and ventilation.
Most people think of insulation as keeping warmth in during winter. But good insulation also keeps heat out during summer. A well-insulated loft stops the sun baking through the roof tiles and heating up the rooms below. If your upstairs bedrooms are unbearable in this weather, there's a good chance your loft insulation is either missing, too thin, or has been compressed over the years. The recommended depth is 270mm, and I check this during every EPC assessment.
Single-glazed windows let heat pour in during summer and leak it out during winter. Double glazing makes a real difference to both comfort and your EPC rating. If you've been feeling the full force of the sun through old windows this month, it's worth knowing that upgrading them would likely improve your energy rating as well.
Good ventilation helps regulate temperature in hot weather and prevents condensation and damp in cooler months. Properties with trickle vents in the windows, extractor fans in bathrooms and kitchens, and clear airbricks score better on an EPC than sealed-up homes with no airflow. If you've been opening every window in the house just to get a breeze, your ventilation might need looking at.
Summer is peak season for property sales, and every property needs a valid EPC before it can be marketed. If you're planning to put your home on the market while the weather is good, don't let the EPC be the thing that holds you up.
I can usually visit within 24-48 hours of booking and have your certificate emailed the same day or next day. The assessment takes about 45 minutes regardless of the weather, and I promise I won't leave the front door open and let all the cool air out.
If you're thinking about selling and want to get the best possible EPC rating, the improvements that help in winter also help in summer:
Whether it's 30 degrees or 3 degrees, I'm out there doing EPCs across Greater Manchester and East Lancashire every day. If you need a certificate for a sale, rental or remortgage, book online or give me a call on 07718 285708. I'll get it sorted fast.
Fixed prices from £65, certificate within 24-48 hours. 260+ five-star reviews.
