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How much does wall insulation cost?

Enter your floor area and get an indicative price for insulating the walls of your existing home. It takes about ten seconds, and you do not have to give us your details to see the number.

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Price your walls

Your estimate appears on this page. If you want it in writing, the quote form opens underneath it.

Retrofit Wall Insulation Calculator

Enter the total floor area of your home in square metres to calculate an estimated cost for wall insulation.

This estimate is based on installing CosyWall Insulation at an installed R-Value of R2.2.

Please note, there are many factors that can impact the overall price, so this calculator should only be used as a ballpark indicator. We recommend contacting our team to arrange an insulation assessment of your property and provide an accurate quote.

Safe-R assessor checking the weatherboard walls of an existing New Zealand home

What wall insulation costs

The calculator estimate is based on CosyWall installed to R2.2, and it works from your floor area, so any home of the same size gets the same estimate. Windows, doors, storeys and access all change the real job, so your installer confirms the final price after a site visit. Use the calculator above for an immediate estimate on your own property.

Why homeowners choose CosyWall.

The estimate is one thing. This is what stands behind it.

Installed since 2002

Installed since 2002

CosyWall has been going into New Zealand homes since 2002.

CodeMark certified

CodeMark certified

The CosyWall system holds certificate CMNZ70016.

50 year guarantee

50 year guarantee

Carried on the CosyWall system.

Installed to R2.2

Installed to R2.2

The R-value the estimate on this page is based on.

CosyWall being blown into the exterior wall of an existing home

What moves the price up or down.

The calculator gives you an indicative figure. These are the things that shift it when your local installer prices the job properly.

Your actual walls

The estimate uses floor area alone. On site, your installer measures the walls themselves, less windows and doors, so the shape of your home can move the final price.

How much of the house

Some homeowners do the cold side of the house first and the rest later.

Wall construction

Cavity depth and framing affect how much product a wall takes.

Access

Two-storey walls and difficult access add labour to the installer’s quote.

You do not need to remove your linings.

Retrofit wall insulation is a service call, not a renovation. Most walls can be done from either the exterior or the interior, whichever suits your house.

1Prepare the walls

We drill small holes into your cladding or plasterboard, taking care that they can be easily repaired afterwards.

2Fill the walls

CosyWall is blown into the cavity with specialised equipment, filling the gaps and voids other products leave behind.

3Repair the walls

We fill and sand every hole. We ensure your home is fully weathertight and, on painted cladding, ready for a fresh coat of paint.

“Once we’ve completed the process you’ll never know we were there.”

Wall insulation cost questions.

The questions people ask before they book, answered plainly.

How much does wall insulation cost?

The calculator on this page gives an estimate including GST, installed to R2.2. It works from your floor area, so any home of the same size gets the same estimate. Windows, doors, storeys and access all change the real job, so your installer confirms the final price after a site visit. Use the calculator on this page for an immediate estimate on your own property.

Do you have to remove the linings to insulate an existing wall?

No. CosyWall is blown into the existing cavity through small holes drilled in the cladding or the plasterboard. Every hole is filled and sanded afterwards. We ensure your home is fully weathertight and, on painted cladding, ready for a fresh coat of paint.

What is the estimate based on?

CosyWall installed at an R-value of R2.2 in the walls of an existing home. It is an estimate rather than a quote, so you can see the order of magnitude before you talk to anybody.

Does the cladding type change the price?

CosyWall can be installed in most wall types, including brick, weatherboard, fibre cement, stucco and internal plasterboard. Wall construction and access can move the final figure, which is why the written quote comes from your local installer.

How do I get a written wall insulation quote?

Enter your floor area, and once you have the estimate you can add your details on the same page. The Safe-R network installer for your region will contact you to arrange a quote and do the work.

Is blown wall insulation cheaper than removing the linings and using batts?

Removing and reinstating wall linings is a renovation with its own building, plastering and painting costs. Blown insulation avoids that work entirely, which is why it is the usual choice for an existing home.

Pricing something else?

Acoustic wall insulation calculator

Price insulating an internal wall to reduce noise between rooms.

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Blown ceiling insulation calculator

Price insulating your ceiling or roof space by total roof area.

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Retrofit wall insulation for existing New Zealand homes

How CosyWall works, where it can be installed, and why blown insulation suits an older home.

Read about retrofit wall insulation with CosyWall

Want your wall insulation quote in writing?

Use the calculator for the estimate, then add your details and the Safe-R installer for your region will be in touch to arrange a proper quote. You can also request an insulation quote directly from our team.

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A warm, well insulated New Zealand home