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Address: 2485 Innovation Drive, London, ON N6M 0C8
Telephone: 1-800-265-1914
Opening Hours: Mon-Fri 08:00-16:30
Areas Served: London, Woodstock, St. Thomas, and the surrounding area
The insulation contractor of choice for residential, agricultural, commercial and industrial insulation projects.
In 2025, after more than 40 years of serving Canadians from our original Woodstock, ON location, we relocated our headquarters to London, representing our commitment to growth and better serving our expanding customer base across Ontario.
Established in 1980, Great Northern Insulation has built a reputation as one of Canada's most trusted insulation services providers. For over four decades, we've been dedicated to helping homeowners and builders achieve superior energy efficiency and home comfort.
We maintain our commitment to serving all of Woodstock, London, St. Thomas, Brantford, Stratford and the surrounding regions, ensuring that our longstanding customers continue to receive the exceptional service they've come to expect from GNI.
If you're a homeowner in the London region, improving your home’s energy efficiency and decreasing heating and cooling costs with Great Northern Insulation is a simple process:
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Free AssessmentBook a free assessment from our London team with either an in-home or virtual estimate to learn about energy-efficient insulation upgrades and potential rebate opportunities. |
Get a QuoteOur quotes are always transparent, free, and carry no obligation. We’ll be sure to outline every aspect of your upgrade, including parts other contractors may miss, like attic ventilation and insulation around the hatch. |
Complete Your UpgradesOnce you’ve decided to move forward with your work, our team will schedule an installation date - and our crew that have been upgrading buildings in the London area for more than 40 years will carry out your work. |
If you haven’t heard of Great Northern Insulation before, we’ve been Ontario’s leading insulation contractor since our foundation in 1980. Headquartered in London, Ontario, with branches across the entire province, we operate under a single mission: to provide homeowners and builders with the products and services they need to help reduce their carbon footprint and build safer, more energy-efficient and sustainable communities.
Our work is completed with a satisfaction guarantee. If you are not satisfied with work we’ve completed, we will perform an audit and carry out repairs or upgrades to ensure it meets the signed quote – at no additional cost to you.
We only work with products from industry-leading manufacturers. Every product installed by Great Northern Insulation is fully warranted by its manufacturer, and we are always working to ensure we offer the best quality products on the market.
All GNI crews are trained to ensure a safe, professional installation in your home. We lead the way with employee benefits, too: all employees receive RRSP matching opportunities, competitive pay, health and dental benefits, educational assistance with tuition reimbursement, and more.
We offer a comprehensive range of new construction and retrofit insulation services to improve your home's comfort and energy efficiency.
Our London team specializes in batt and poly insulation, but we also provide a variety of other solutions including spray foam insulation, attic insulation removal and top-up, cellulose insulation, basement insulation, dense-pack cellulose, air sealing, and more.
Proper insulation plays a large role in energy efficiency and sustainability for homeowners and businesses in London, Ontario. Great Northern Insulation offers a comprehensive range of insulation services installed by local, trained professionals. We offer various insulation types, including the eco-friendly option of cellulose, which is particularly effective for attic insulation.
Alongside cellulose, we also provide advanced solutions like spray foam insulation, which offers very high insulative value as well as moisture barrier qualities. These services are designed not just to enhance the comfort of your property, but also to contribute to long-term energy savings and improved indoor air quality.
By completing a free assessment with Great Northern Insulation and installing energy-efficient upgrades, such as cellulose for attics and spray foam insulation for walls, basement rim joists, or more, our London team helps home and business owners significantly improve their home's energy efficiency and reduce their environmental impact.
Below are just a few highlight services available at our London branch. Reach out to us for a free assessment and a tailored strategy for your needs!
For most homeowners, attic insulation is a home improvement that is very often underestimated.
Spray foam insulation is widely recognized as the most versatile insulating product on the market today.
Learn More
Fibreglass Batts are an extremely common form of insulation made from extremely fine fibres of glass woven together into thick pads.
2485 Innovation Drive
London ON
N6M 0C8
TOLL FREE: 1-800-265-1914
25 Lincoln Ave
St. Catharines, ON
L2P 2C7
TOLL FREE: 1-800-265-1914
15 Corvus Court
Nepean ON
K2E 7Z4
TOLL FREE: 1-800-265-1914
1027 Elwell Park Road
Gravenhurst, Ontario
Canada P1P 1R1
TOLL FREE: 1-800-265-1914
29 Ferndale Industrial Drive
Barrie, Ontario
Canada L4N 9V5
TOLL FREE: 1-800-265-1914
2 Guided Court
Etobicoke, ON
M9V 4K6
TOLL FREE: 1-800-265-1914
103 North Port Road
Port Perry, Ontario
Canada L9L 1B2
TOLL FREE: 1-800-265-1914
450 Industrial Dr,
Toronto (Milton), Ontario
Canada L9T 5A6
TOLL FREE: 1-800-265-1914
Great Northern Insulation - Better Business Bureau Profile.
Best of 2021
HomeStars has ranked Great Northern Insulation as a company that goes above and beyond in every aspect of business for the year of 2021.
Best of 2022
HomeStars has ranked Great Northern Insulation as a company that goes above and beyond in every aspect of business for the year of 2022.
GNI is the Authorized & Trusted Insulation and Air Sealing Installer for Lowe’s
Over 40 Years in Business
At GNI, we service your project with the most experienced staff in the industry. Ongoing professional development is an obsession at GNI and we will not compromise at any level to bring to our customers the very best Installers, Sales Representatives, Customer Care Personnel, Field Superintendents, Estimating and Technical Support to your project.
100% Canadian
Great Northern Insulation is recognized as Canada's largest full-service insulation contractor. GNI is 100% Canadian owned, proudly serving Ontario customers since 1980.
Do it right the first time
- with foam mastersTM
January, 2021 regulatory phaseout of hydrofluorocarbons (HFCs) with the introduction of WALLTITE CM01. Using hydrofluorolefins (HFOs) with lower global warming potential (GWP) compared to HFCs, WALLTITE CM01 is the next generation of spray foam insulation.
Huntsman HEATLOK® SOYA HFO™
Heatlok® Soya HFOTM leverages Honeywell’s latest Solstice® Liquid Blowing Agent technology. This new hydrofluoroolefin (HFO) blowing agent is the most environmentally conscious blowing agent produced to date, with a zero ozone depletion potential (ODP) and a global warming potential (GWP) of 1, which is more than two orders of magnitude (99.9%) lower than HFCs used in this industry.
3MTM products.
Quality + Performance = Savings
3MTM energy-saving products are designed to keep warm air in, and cold air out, while keeping energy bills down. Products optimize energy efficiency in buildings and homes; improve indoor environment for occupants; and effect the reduction of seasonal energy costs. 3M products are authorized for LEED credits (Leadership in Energy/Environmental Design).
Holmes and Holmes
Mike Holmes and his son Mike Jr. (MJ) convert MJ’s bachelor bungalow into a two-storey home for MJ and his girlfriend Lisa. Choosing the newest materials and build techniques, the father and son team follow Mike’s famous motto – “Make it right.” The show can be watched on HGTV and DIY Network.
Enbridge Incentives
The Home Efficiency Rebate Plus program offers up to $10,000 in home reno rebates – and Great Northern Insulation can pave the way.
Great Northern Insulation proudly abides by a renovation-specific Code of Conduct set by RenoMark™.
We are Verified & Bonded by eRenovate. When you choose to proceed with our services through their platform, you receive the gaurantees set forth through their program.
The GNI crew have been featured installing insulation on Love It or List It - have you seen our logo in an episode?
Climatizer
CLIMATIZER PLUS cellulose insulation is manufactured from a minimum of 85% locally-sourced post-consumer recycled newsprint. Non-toxic additives are applied to the uniquely fiberized paper generating a building material with superior thermal and acoustic properties, as well as exceptional resistance to fire, moisture, mould and pests.
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