Himalaya Group
“From initial estimate to complete installation the entire Himalaya team was professional and on time, communication was great, crews courteous and friendly with attention to a clean work site.”
Best Insulation Contractors in London, ON
15 contractors listed · all 15 in London · 5 open weekends · 11 rated 4.5+
Data verified October 18, 2026
Net Zero Insulation Inc
“Will be recommending Net Zero to any friends and family who are needing insulation services, and will have them back to take a look at our basement!”
1st Choice Home Solutions
“I would definitely recommend and I will be using them in the future for any other things I need That they would be able to complete”
Davidoff Roofing (London) Ltd
“It was really an easy decision to make based on the proposed materials and processes, the cost, and the long-standing reputation of Davidoff Roofing.”
Accell Roofing Inc
“I have had the pleasure of dealing with Accell Roofing (and John Acton) for almost two decades and have always been impressed by their professionalism and quality work.”
Murray Shaw Roofing
“Did our entire roof install in a day and left the area around the house and driveway cleaner than when they got here!”
The 15 contractors listed for London, ON insulate attics, basements, headers and crawl spaces. Details under each one about materials, hours and advertised services are copied from the company's own site; star ratings and comments come from public reviews.
Area overview: London, ON
All 15 contractors we list here are in London itself. We have 16 contractors in London on file; this page shows the highest-rated 15. 14 of the contractors on this page have a rating, from 4.0 to 5.0 across 516 reviews; 4 have 50 or more reviews and 11 are rated 4.5 or higher. When customers rate these contractors on specific qualities, they most often praise professionalism (95%), quality (85%) and responsiveness (74%). The topics that come up most in reviews of the contractors on this page are "estimates", "price" and "cleanliness". 5 are open on Saturdays and 3 on Sundays. Domain records put 4 websites of the contractors on this page at ten or more years old; the oldest dates from 1997. 1 offers emergency call-outs; 3 offer financing or payment plans; 7 give free estimates; 1 is family- or locally-owned and 2 list coupons or special offers. We have a website on file for 14 of the contractors on this page; 12 publish a contact page; 11 list a public email and 2 take bookings online. We count these figures across the contractors on this page; hours and prices change, so confirm the details with the contractor before you book.
Will anyone assess the house at no charge?
No charge assessments are advertised by 7 of the 15 contractors on this page. Treat that as a sales visit with a tape measure. A paid energy evaluation is the thorough version, and in some provinces it is also the paperwork that opens the door to a rebate program.
Prime Air & Water
“The 2 gentlemen who came to our house were amazing, very helpful, friendly and well mannered.”
Polar Energy Systems
“Chris is a great insulation contractor who did a great job topping up my blown in attic insulation.”
Skylar Group Ltd.
“While he was here he notice some of my siding and facia were loose and fixed at no charge !!!!”
London Star Drywall
“Thank you to Zaya and his team for taking care of all my requests.”
Belform Insulation
Bay Insulation Systems
Stucco Center
“Great-spirited gentleman at the sales desk, honest, patient, and even better prices on strong quality base and finish stucco coats and paint.”
Home Choice Insulation
“We would highly recommend Luke and his team for anyone looking for a professional, courteous service.”
Tornado Insulation
Why these companies made our list
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