What is the Best Insulation for Existing Walls?

If your home was built before the 1990’s and you are having a hard time keeping it warm this winter, you may find it has little or no wall insulation. Even newer homes can have thin or patchy insulation that doesn’t hold in the warmth. If you are looking for the best insulation for existing walls, a blown wall insulation system like CosyWall is one of the most effective options. 

Why blown insulation is ideal for existing homes 

Blown wall insulation is designed for retrofitting into homes without the need for major renovations. Unlike other methods that involve removing wall linings or replacing cladding, CosyWall can be installed quickly and with minimal disruption. This means you can upgrade the comfort and efficiency of your home without weeks of messy building work. 

Most installations can be completed in a single day. Our team drills small, tidy holes in the wall cladding or linings, blow in the insulation to fill the entire cavity, then seal and finish the holes so everything looks neat. The process is clean, fast and designed to keep your home weathertight. 

How CosyWall insulation works 

CosyWall is a high-performance dry fibre insulation. It is installed at a density that completely fills the cavity, leaving no gaps or voids where heat can escape. Once the insulation is in your walls it stays in place and will not slump or settle over time. This ensures it performs for the life of your home, keeping it warm in winter and cooler in summer. 

The system is CodeMark certified, which means it meets strict New Zealand building standards. You can be confident the product is tested, proven and installed using a controlled process that protects the structure of your home. 

The R-values you can expect 

R-values measure how well insulation resists heat flow. The higher the R-value, the better it performs. CosyWall delivers higher R-values than many traditional insulation products because it is blown in at a density that fully packs the wall cavity. By removing gaps and voids, the insulation forms a continuous barrier that helps hold the warmth in and keep the cold out. 

This can make a big difference to your power bills. With proper wall insulation, your home loses less heat, so your heating system doesn’t have to work as hard to keep the temperature comfortable. 

Fast and simple installation 

Most CosyWall installations are completed in one day. Our team will assess your home, explain the process, and recommend whether the insulation should be installed from inside the home or through the exterior cladding. The holes are small and are sealed once the insulation is in place, leaving your home tidy and protected. 

Because there are no major renovations involved, you can usually carry on with your day while the work is being done. Once finished, the difference in comfort is noticeable straight away. 

Take the next step 

If you are ready to find out how much it costs to insulate your walls, try our free wall cost calculator. You can also contact our team to arrange a free assessment. We will help you choose the best insulation for existing walls and create a warmer, more comfortable home for you and your family. 

Read more about wall insulation for existing homes.