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Exterior and Interior Residential Home Insulation

March 14, 2016

To one degree or another, residential homes are insulated - the exterior walls; the roof and attic; even the basement. But as many homeowners are bound to discover, not all insulation performs up to scratch. The result - poor overall energy efficiency, and energy bills that are higher than need be. The thing is, a good part of a home's structure (known as the "building envelope") is exposed to the exterior elements. This provides an opportunity for air to flow in and out of the home, setting the stage for poor energy efficiency throughout. The idea behind insulation is to prevent airflow. It means preventing heated indoor air from escaping in the winter, and preventing hot outside air from coming into the home in summer. In this respect, a reputable insulation contractor can determine whether exterior or interior retrofitting is best for the insulating project at hand. As well, the contractor can be valuable in determining the type of insulation product to use, and the installation method that best meets the need. For the homeowner, performance and affordability will be key. There are a number of determining factors when choosing between exterior and interior retrofitting. For the typical homeowner, it is good to understand the basics - it will make for a better working relationship with the contractor and will make for better decision making throughout the lifespan of the project.

  • assessing the exterior/interior finishes of the home and the ease of a retrofit
  • considering the physical construction of the home and the potential for changes
  • evaluating other renovation work that might be expedited all at the same time
  • calculating the extent of energy savings that could be achieved with each option

Interior insulation retrofits clearly offer advantages (and consequent cost savings). Firstly, all the work can be performed year round. Secondly, there is much less demolition required. And thirdly, there are far fewer construction and bylaw ramifications. Additionally, where other renovation work may affect any interior finishes, this is the perfect opportunity to seal and insulate. Indeed, where a basement is getting renovated, a professional insulation retrofit can deliver superb results in personal comfort and annual utility savings. When it comes to a major retrofit project, like installing a new "air barrier system" for the entire home, then the exterior option is preferable. Here, an insulation retrofit can deliver the maximum in performance - a seamless, airtight, envelope of insulation right around the home. Obviously, exterior work won't affect the interior finishes, and won't have any impact on the occupants. And as long as the budget permits, the new "air barrier system" will contribute greatly to both structural durability and insulating performance. Speaking of budget, any insulation retrofit should take into consideration the initial project investment, and the longer-term "payback" period. Here again, a reliable contractor will be invaluable in working out project options that best suit the homeowner's priorities and budget. And in many cases, the annual savings on heat and air conditioning will offset the original project investment.

Western Ontario

935 Keyes Drive
Woodstock, Ontario
Canada N4V 1C3

Phone: 1-800-265-1914

Fax: (519) 539-7946
TOLL FREE: 1-800-265-1914

Muskoka, Haliburton, Northern Ontario

1027 Elwell Park Road
Gravenhurst, Ontario
Canada P1P 1R1

TOLL FREE: 1-800-265-1914

Central Ontario

29 Ferndale Industrial Drive
Barrie, Ontario
Canada L4N 9V5

TOLL FREE: 1-800-265-1914

Greater Toronto Area

2 Guided Court
Etobicoke, ON
M9V 4K6

TOLL FREE: 1-800-265-1914

GTA East

103 North Port Road
Port Perry, Ontario
Canada L9L 1B2

TOLL FREE: 1-800-265-1914

South Central Ontario

450 Industrial Dr,
Toronto (Milton), Ontario
Canada L9T 5A6

TOLL FREE: 1-800-265-1914

Eastern Ontario

1035 Moodie Dr #1,
Nepean, ON
K2R 1H4

TOLL FREE: 1-800-265-1914

Niagara Region

25 Lincoln Ave
St. Catharines, ON
L2P 2C7

TOLL FREE: 1-800-265-1914


Great Northern Insulation - Better Business Bureau Profile.

Homestars Best of 2021 Award

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.

Homestars Best of 2022 Award

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

Trusted for Over 40 Years

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

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.

Foam Masters

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.



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

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.

As Seen on Love It or List It

The GNI crew have been featured installing insulation on Love It or List It - have you seen our logo in an episode?

Climatizer Cellulose


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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