How Much Does Adding a Second Storey Cost in NZ? (2026)
Typical cost in NZ
$300,000
A second-storey addition in New Zealand typically costs around $300,000, ranging from $200,000 for a budget job to $480,000+ at the premium end. The figures below break down what each level gets you, what drives the price, and how it varies by region.
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Check a builderSecond-Storey Addition cost by level
Budget
$200,000 – $275,000
Around 50m² basic-to-mid second storey on a simple roofline.
Mid-range
$275,000 – $350,000
Larger or higher-spec addition, with some reworking of the floor below.
Premium
$350,000 – $480,000
High-end finishes with complex structural reinforcement and access.
What changes the price
| Factor | Impact | Why |
|---|---|---|
| Structural reinforcement | +$20k–$50k | The existing house must carry the new floor — foundations and framing often need strengthening. |
| Scaffolding & access | +$10k–$20k | Working at height for months. |
| Living elsewhere during the build | +$ varies | Removing the roof usually means moving out for part of the project. |
| Consent, design & engineering | +$12k–$33k | Consent ($3.5k–$8k+) plus design and structural engineering. |
Second-Storey Addition cost by region
Indicative cost based on the typical figure, adjusted for regional labour and material differences.
Auckland
$345,000
Wellington
$318,000
Christchurch
$294,000
Regional NZ
$270,000
What's usually included, and what isn't
Usually included
- New floor structure
- Framing, cladding & roof
- Stairs
- New rooms fitted out
- Scaffolding
Usually extra
- Reworking the entire ground floor
- Temporary accommodation
- Landscaping
- Consent & development contributions
Typical timeline
4–8 months
Building consent
Usually required
A second storey is significant structural work and requires a building consent, with structural engineering.
Read the full consent answerA second-storey addition is one of the biggest cheques you'll write.
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Questions to ask before you sign
- Can the existing foundations and framing take a second storey — who confirms that?
- How will the house be protected from weather during the build?
- What's the realistic timeline and payment schedule?
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Ready to get quotes? Browse registered second-storey addition trades by city, then run a background check on each one before you sign.
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Frequently asked questions
- How much does it cost to add a second storey in NZ?
- A second-storey addition typically costs $200,000–$450,000+, around $3,500–$5,500 per m² — roughly 10–20% more than an equivalent ground-floor extension due to structural reinforcement and access.
- Do I need to move out during a second-storey addition?
- Usually for part of it — removing the existing roof exposes the house to weather, so most homeowners move out during the riskiest weeks.
Second-Storey Addition costs by city
Related cost guides
Sources: Superior Renovations second-storey guide 2025; Refresh Renovations loft/second-storey estimates; QK Renovation Auckland extension guide 2026. Figures are 2026 estimates for guidance only and exclude GST unless stated, so always get written quotes for your specific project. Last updated 2026-05.