How Well Should My Home Be Insulated?

Many houses today aren’t insulated properly. As you renovate or build your own home, save yourself some money on energy costs by insulating well. Beefing up your insulation is also a good idea if you are looking to get a loan, since it can raise the value of your house as well as possibly make you eligible for tax breaks and federal rebates.

But there are more reasons to insulate your home well than just saving yourself money. There are building regulations for insulation and the Federal Trade Commission requires you to provide information on the type, thickness, and R-value of the insulation installed in the house in every sales contract. Many sellers will have their homes insulated at the standard, rather than optimal level to keep the house priced competitively. But it is easier and more cost-effective to insulate your home optimally as you build it

R-Value
The R-value simply tells how effective insulation is. The higher the R-value, the better the insulation. Your local building codes will dictate the minimum R-value you will need for attics, basements and exterior walls. There are also maps available online that split the country into different heating zones with different recommended R-values. Just do a quick web search for R-value Recommendations to find one.

There are also calculations for entire wall R-values. But an R-value doesn’t take in all the factors (ex. air tightness, moisture tolerance, thermal mass) for a wall that need to be considered when determining whole-wall thermal performance.

Vapor Barriers
Batts and blankets (what you’ll be using for the majority of your insulation) have built-in vapor barriers to keep condensation from rotting wood and corroding wires. But for other forms, you’ll have to nail down a makeshift vapor barrier before laying down insulation. Good substitutes include: aluminum foil, wrapping paper, or plastic sheeting.

However, if you are laying new insulation over old insulation, be sure to cut holes in the vapor barrier or buy insulation without a barrier.

Don’t Miss Anything
Here’s a checklist of areas you should remember to insulate:

Between attic collar beams.
Attic floors.
Floors above crawlspaces.
In a cockloft beneath a flat roof.
In knee walls adjacent to attic spaces.
In roof rafters adjacent to living spaces.
In knee walls adjacent to attic crawlspaces.
In exterior walls on the heated areas of a sloping roof.
In exterior walls adjacent to unheated spaces.
Ceilings below unheated areas.
Foundation walls in heated basements.
Exposed framing above foundations.
Exterior walls below window sections.
Attic trap doors.
Floorboards or catwalks in attics.
Air ducts for heating and cooling.
Conduits, pipes, and chimneys going up through your attic floor.