Where to start
| Area | Why it matters | Typical approach |
|---|---|---|
| Ceiling / roof | Usually the biggest source of heat gain and loss | Batts or blown-in insulation in the roof space |
| Walls | Significant in older homes with uninsulated cavities | Blow-in or injected products for existing walls |
| Underfloor | Helps raised timber floors in cooler climates | Batts or boards fixed under the floor |
Understanding R-values
The R-value measures resistance to heat flow — higher means better insulating. The right R-value depends on your climate zone and where the insulation goes. Ask installers what they recommend for your zone and why, and make sure the R-value on the quote matches the product installed.
Safety first
Insulation in roof spaces must be installed with proper clearance from downlights, flues and electrical equipment. Ask how the installer manages electrical safety, whether power is isolated during work, and how existing downlights will be handled.
Rebates and incentives
Insulation incentives vary widely by state and change often. Check the energy.gov.au — Rebates and assistance finder for programs in your area.
Last checked 21 October 2026. Programs change often — always confirm eligibility with the program and your installer.
How to compare insulation quotes
- The installer's licence and any required accreditation, with numbers you can check.
- An itemised quote: exact brands and model numbers, quantities and what's included.
- Any rebate or certificate discount shown as a separate line, with who claims it.
- Product warranty, performance warranty (if relevant) and the installer's workmanship warranty — in writing.
- Who handles network/connection approvals and compliance certificates.
- Deposit amount, payment schedule and what happens if the job is delayed.
- Product name, R-value and area (m²) for each part of the job.
- Removal of old or damaged insulation, if needed, and how it's disposed of.
Frequently asked questions
Can I insulate walls in an existing house?
Often, yes. Blow-in or injected products can fill wall cavities without removing linings, depending on the wall construction.
How long does ceiling insulation take?
Many single-storey ceiling jobs are done in a day. Access, roof height and removing old insulation affect timing.