Good insulation is the single most cost-effective home improvement you can make in NZ — it reduces heating bills, improves warmth, and cuts condensation. Here's what insulation costs in NZ in 2026, what R-value you need, how to access government subsidies, and how to find a certified installer near you.
Insulation Cost NZ 2026
| Type | Area | Typical installed cost |
|---|---|---|
| Ceiling insulation (blown fibre) | 100m² house | $1,500–$2,800 |
| Ceiling insulation (batts) | 100m² house | $1,800–$3,200 |
| Underfloor insulation (polyester batts) | 100m² house | $1,800–$3,500 |
| Underfloor insulation (foil + batts) | 100m² house | $2,200–$4,000 |
| Wall insulation (retrofit, injection foam) | Per m² | $40–$90/m² |
| Wall insulation (new build, batts) | Per m² | $15–$35/m² |
Prices include supply and installation. GST extra. Warmer Kiwi Homes subsidy can reduce eligible household costs by 80%+ — see below.
Insulation R-Values: What You Need in NZ
The R-value measures thermal resistance — the higher the number, the better the insulation. NZ Building Code (H1) sets minimum R-values by climate zone:
| Climate zone | Cities | Ceiling min | Underfloor min |
|---|---|---|---|
| Zone 1 | Northland, Auckland | R2.9 | R1.3 |
| Zone 2 | Hamilton, Tauranga, Gisborne | R3.3 | R1.3 |
| Zone 3 | Napier, Palmerston North, Nelson | R3.3 | R1.3 |
| Zone 4 | Wellington, Christchurch | R4.0 | R1.3 |
| Zone 5 | Central Plateau, Southern Alps | R6.6 | R2.0 |
| Zone 6 | Queenstown, Invercargill | R6.6 | R2.5 |
For existing homes: These are minimums for new builds. For retrofits, EECA recommends installing to at least the current new build standard for your zone, or higher if budget allows — insulation is a one-time job and the marginal cost of higher R-value is small.
Warmer Kiwi Homes Subsidy 2026
The Warmer Kiwi Homes programme (EECA) subsidises insulation for eligible homeowners:
- Subsidy level: Up to 80% of the cost for eligible households
- Who qualifies: Own and live in your home; receive a Community Services Card, NZ Super, Veteran's Pension, or Disability Allowance; or live in a low-income area (based on address)
- What's covered: Ceiling and underfloor insulation (not wall insulation)
- How to apply: Through an EECA-registered installer — they assess eligibility and manage the subsidy application on your behalf
For many eligible NZ households, ceiling and underfloor insulation costs $300–$600 after subsidy rather than the full $3,000–$6,000.
Types of Insulation and What They're Best For
Ceiling Insulation
Blown fibre (glasswool or polyester): Blowing loose fibre into the ceiling cavity. Fast to install, no gaps, suits irregular or obstructed spaces. The default choice for retrofitting existing ceilings without access.
Batts (glasswool or polyester): Pre-cut slabs fitted between rafters. Common in new builds and ceilings with easy access. Polyester batts are non-irritating and easier to handle than glasswool.
Underfloor Insulation
Polyester batts: Fitted between floor joists from below. Non-irritating, hold their shape, long lasting. The standard choice for most NZ homes with suspended timber floors.
Foil: Reflective foil acts as a radiant barrier. Often combined with batts. Effective in warm-floor homes but doesn't provide as much thermal resistance as batts in very cold climates.
Wall Insulation
Wall insulation in existing homes requires injecting foam into the wall cavities. This is a specialist job — holes are drilled in the exterior cladding (or interior), foam is injected, then holes are plugged. Not suitable for all cladding types (particularly older weatherboards). New builds have batts installed before linings go on.
Internal Wall Insulation (Soundproofing)
Polyester or glasswool batts in internal walls reduce sound transfer between rooms. Popular in media rooms, bedrooms adjacent to living areas, and home offices.
Finding Certified Insulation Installers Near You
EECA Warmer Kiwi Homes subsidies must be installed by an EECA-registered installer. These installers have been vetted, trained, and assessed by EECA.
EECA installer search: warmerkiwihomes.govt.nz — enter your address to find registered installers in your area.
Non-subsidised work: Any insulation company can install retrofit or new build insulation, but using a Registered Master Insulator (if applicable) or a company with a good track record is advisable.
What to ask an installer: 1. Are you EECA-registered? (Required for subsidised work) 2. What R-value will be achieved after installation? 3. What insulation product are you using (brand, specification)? 4. Is the quote for supply and installation including GST? 5. Do you assess existing insulation before quoting? 6. Do you install both ceiling and underfloor, or do I need separate companies?
Red flags: - Can't tell you the R-value that will be achieved - No mention of EECA registration when you ask about the subsidy - Quote doesn't specify the insulation product
Find insulation installers near you: Insulation Installers NZ | Post Your Job Free
Frequently Asked Questions
How much does ceiling insulation cost in NZ? For a 100m² house, expect $1,500–$2,800 for blown fibre or $1,800–$3,200 for batts, fully installed. Eligible households can receive an 80% Warmer Kiwi Homes subsidy — dropping the cost to $300–$600.
How much does underfloor insulation cost in NZ? For a 100m² suspended floor: $1,800–$3,500 installed. After Warmer Kiwi Homes subsidy (if eligible): $400–$700.
Can I install insulation myself in NZ? Ceiling and underfloor batts can be DIY-installed legally. However, to access the Warmer Kiwi Homes subsidy, you must use an EECA-registered installer. DIY also risks gaps and missed areas that reduce performance — professional installers are trained to achieve consistent coverage.
How long does it take to install insulation? A typical 3-bedroom home: ceiling and underfloor insulation both done in one day (2–4 hours each). You can use the home normally while work is being done; installers access the ceiling and underfloor without disturbing interior spaces.
What R-value should I get for my NZ home? At minimum, the current NZ Building Code standard for your climate zone. For a Wellington or Christchurch home (Zone 4), that's R4.0 ceiling and R1.3 underfloor. Paying for R6.6 ceiling in a Zone 4 home adds modest cost but meaningfully improves performance in cold winters — worth it if your ceiling space allows.
Related: Insulation Cost NZ | Heat Pump Installation NZ | Find Insulation Installers Near You