Heritage Restoration, Inc.

Can I Over Insulate My House?

Can I over insulate my house?


South Kingstown

The short answer is it depends. The energy efficiency effectiveness and indoor air quality depends on if you are doing it the right way in the right place. Insulation must be part of the design intent or part of a scientific integration since it is an integral part of the building system.

Designing and building a new building is the perfect opportunity to incorporate high efficiency windows and doors, vapor barriers, and flashing details that work in tandem with proper insulating techniques. Expectations of building performance and maintenance are essential for a building to sustain the expected energy efficiency performance. Any weaknesses in the envelope design, materials, or construction can negate the performance of insulation.

Building performance is key to insuring that insulation will work as expected. Too often insulation is used as a method towards energy savings without actually trying to understand the building. Every building is unique, with no two being the same. Each has their own environmental exposures and location, affecting the levels of moisture that move in and out of the house. Each has their own construction techniques, where flashing, airflow, water management, and the exterior envelope can either introduce or shed water and moisture. Understanding a building’s unique characteristics is a science, and must be investigated and understood.

Experimenting with building performance can have consequences. For thousands of years, indoor air quality was less of an issue since buildings had really good air exchanges. And while it was cold, the air was a good thing. There were many combustibles without proper or complete exhaust methods, so a good breeze kept most buildings healthy for the occupants. But since the 1970’s, the world has focused on energy efficiency and conservation, making buildings a target for retrofit.

Making buildings that were not designed to be efficient act efficient is a science for some and an experiment for others. This is where over insulating a building and making it too air tight is a problem. There are indoor air quality and air exchange standards every building should have. Many retrofitted buildings do not get the analysis necessary to determine if a mechanical air exchange is necessary. People become the canary in a coal mine, causing a slow creep to an unhealthy building, often eluding victims and doctors as the cause for allergies or other health reactions.

Take the time and expense to hire an energy auditor if you are retrofitting with insulation. The auditor can first determine what your building’s really needs, taking baseline readings and analysis before the retrofit. Issues like moisture, water, and airflow must be accounted for. If you are going through your utility, ask for a blower door test prior to and after the insulation retrofit.

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