What is retrofit insulation?
Retrofit insulation is insulation added to a home after it has been built. Safe-R blows loosefill fibreglass, also called glasswool, into the ceiling, underfloor and wall cavities of an existing home. You get a warmer, drier house without removing linings or renovating.
You may also hear it called retro insulation, pumped insulation or injected insulation. The idea is the same. The insulation fills the spaces your home already has, and your rooms stay as they are.
Where to retrofit insulation in an existing home.
Start with one area and do the rest later, or insulate the whole home at once. Each area has its own Safe-R system.
Walls
We fill existing walls by drilling through the inside lining or the outside cladding, so nothing comes down. CosyWall suits brick, weatherboard, stucco, fibre cement and more, and it is CodeMark certified. In internal walls it also helps reduce sound between rooms.
Ceiling and roof
Loft is blown evenly across the roof space and reaches the tight edges and awkward corners that segment products miss. Already have some insulation? Loft can go over the top as an extra layer.
Underfloor and midfloor
Cold floors are often the first thing you notice in an older home. Warmafloor is blown in from under the house and held in place by a breathable membrane, which also stops air and moisture moving up through the gaps between floorboards. It suits midfloors too.
Why blown insulation suits older homes.
Older homes are rarely square, and their walls, ceilings and floors are full of wiring, pipes and framing. Segment products have to be cut to fit around all of it. Blown insulation flows into place instead.
“From the minute I had it insulated and now 7 years later, there’s not a drop of moisture anywhere in the house. It’s made a huge difference to my life.”
Retrofit insulation for rentals.
Under the Healthy Homes insulation standard, every private rental must have ceiling insulation, and underfloor insulation where the floor is suspended, wherever it is reasonably practicable to install. All private rentals have had to comply since 1 July 2025. Existing ceiling insulation generally needs to be at least 120mm thick and in reasonable condition. Wall insulation is optional under the standard, though insulating the walls can make a rental warmer and drier. Blown insulation can top up or replace what is there with little disruption. Details are at tenancy.govt.nz.