11 Apr Why exterior insulation should be on your radar
Most of us do not think twice about our insulation when it comes time to build a house. The industry standard is to apply interior insulation – most commonly batt insulation – inside the walls of the home.
While interior insulation has its advantages, exterior insulation is becoming better recognized because of the benefits it carries over its counterparts.
This article explains the differences between interior and exterior insulation so that you can choose which option is better for your home.
Interior Insulation vs. Exterior Insulation
Interior insulation advantages
- Lower material costs, as the materials are more common
- Lower installation costs
- Best installed on existing foundation walls
Interior insulation disadvantages
- Can be affected by moisture, leading to mould contamination inside the home
- Offers zero waterproofing for the home
- Most importantly, interior insulation reduces the interior floor space of your home
Exterior insulation advantages
- Acts as a built-in rain screen for the home’s exterior, effectively combining two materials into one with high efficiency
- Allows you to achieve higher R-values for your home. This will be explained below, but in effect, increases your home’s square footage
- Reduces moisture infiltration into the structure
- May minimize damage to your home’s foundation in climates where the ground freezes in winter and thaws in spring – applies to the Interior and Northern BC
- Higher overall insulation performance
Exterior insulation disadvantages
- More difficult to install for some applications
- Higher material cost
Why use exterior insulation on your home?
The main reason to install exterior insulation on your home is to achieve a higher Floor Space Ratio (FSR).
In the Vancouver real estate market, where homes sell for around $1,000 per square foot, increasing the sellable square footage of your home can represent a major win for your home’s resale value. Increasing your home’s Floor Space Ratio happens because of two factors:
- Decreasing the amount of wall included in fsr if you go exceed R22
- Increasing your home’s energy efficiency
In addition, your home’s energy audit, or energy evaluation, will test how well the insulation protects your home’s interior from heat loss and moisture. The measure of thermal transfer in your home is called the R-value, and a higher R-value means your home is better able to resist heat loss.
When your home achieves a high R-value, this allows the home to also receive a higher FSR. In some cases, a high R-value could add 80 square feet to your home. An engineer can help determine what material, and the thickness of material, is required to achieve your target R-value and improve the FSR.
And a higher FSR means better resale value.
80 additional square feet x $1,000 per square foot = an extra $80,000 in your pocket.
Exterior insulation in your custom home design or home renovation
Whether you are planning to build a custom home in the Vancouver area, or it is time to retrofit your home’s insulation, you may wish to consider exterior insulation.
The Lower Mainland has a variety of installation companies that can provide this service, however the work begins with your home’s residential design or renovation design, to plan how to add the insulation to the exterior walls.
Be sure to work with a general contractor and insulation installer who has experience with exterior insulation and can help advise you on costs and the best material for this type of energy-efficient insulation application.