Imagine being able to add a warm, self-contained space out the back for Nana, a young adult saving for their first home, or even a caregiver, without the paperwork marathon. That’s exactly what New Zealand’s new granny flat exemption delivers.

Passed into law on 24 October 2025, the change lets homeowners build a secondary dwelling up to 70m² without a building consent—as long as it’s simple in design, meets the Building Code, and is built by qualified tradespeople. The new rules are set to take effect in early 2026.

What’s changed (in plain English)

• Consent-free: No building consent needed for a minor dwelling up to 70m².
• Still must be safe: Your build must comply with the Building Code and be constructed by professional tradespeople.
• Tell your council: You’ll notify the council before you start and after you finish.
• Resource consents: The Government plans national direction to remove resource consent requirements for these units. (They’ve signalled updates to RMA settings so councils can’t add extra hurdles for standard builds.)

Bottom line: Less red tape for straightforward, code-compliant small homes.

Who this helps most

• Multi-generational families wanting a separate but nearby space for kaumātua, young adults, or whānau with disabilities.
• Rural employers needing on-site accommodation for seasonal staff.
• Homeowners exploring extra income (e.g., boarders or long-term rental).
• Communities where high housing costs hit hardest—Māori, Pasifika, seniors, and people with disabilities stand to benefit from more flexible living options.

What you can (and can’t) build

You can build:

• A detached secondary dwelling up to 70m² (1–2 bedrooms fits comfortably).
• A simple, single-storey design using standard construction methods.
• A home that meets all Building Code performance requirements (structure, weathertightness, fire, plumbing/drainage, insulation/energy efficiency, access).

You can’t bypass:

• The Building Code (no corners cut—this isn’t “no rules”, it’s “no consent”).
• Qualified workmanship—the exemption expects professional trades.
• Council notification—you still need to tell them before and after the build.
• Basic site constraints—think services, flooding, access, on-site car parking if your local plan requires it (watch for separate resource rules until national direction lands).

Expected impact (and realistic limits)

• Government expects around 13,000 new granny flats over the next decade.
• That’s helpful—but it’s a modest lift in the national housing stock.
• Budget reality check: Many builds will sit in the $200k–$300k range depending on site works, services, and fit-out.
• Infrastructure (sewer, stormwater, driveways, power upgrades) can affect feasibility and cost.

Quick start checklist

Before you design

1. Assess your site: services (water, wastewater, stormwater), access/parking, sunlight, privacy, setbacks, flooding/overland flow.
2. Sketch a simple plan: aim for compact, single-storey, standard specs.
3. Talk to your insurer & lender: confirm cover and any lending conditions.

During design & build
4. Design to the Building Code: structure, fire, insulation, ventilation, moisture, accessibility where relevant.
5. Hire licensed pros: LBP builders, registered sparkies/plumbers/drainlayers.
6. Notify council: lodge the pre-build notification. Keep records (plans, producer statements, product certificates, gas/electrical CoCs).

On completion
7. Final checks: compliance docs, warranties, as-builts for services.
8. Notify council again: submit your post-build notification.
9. Update your insurer; consider valuation and rates implications.

Design tips to keep costs down (and value up)

• Stick to rectangles and a simple roof form (mono-pitch or gable).
• Standard spans and products reduce engineering and lead times.
• North-facing living with good eaves = warm, cheap to run.
• Universal design (level entry, wider doors, step-free shower) future-proofs for whānau and guests.
• Bundle site works (trenching power/data/water together) to save.
• Plan storage cleverly (full-height cupboards, attic trusses if allowed).

Finance & cashflow ideas

• Top-up on existing mortgage (home-equity release).
• Construction loan / progressive drawdown with a fixed-price build contract.
• Offset accounts to reduce interest during construction.
• Rental contribution modelling: even modest board income can ease repayments—stress-test at today’s rates plus a buffer.

Risks & watch-outs

• Scope creep: custom features and complex shapes add cost fast.
• Ground conditions: soft soils, retaining, or drainage upgrades can surprise.
• Services capacity: wastewater upgrades can be the budget killer—check early.
• Insurance & compliance paperwork: keep every certificate and product warranty.

Frequently asked questions

Do I really not need council consent?
You won’t need a building consent if you meet the exemption criteria. You do need to notify council before and after, and you must meet the Building Code. Separate resource consent needs are being streamlined by national direction—watch for updates.

Can I rent it out?
Generally yes, but confirm local rules, insulation/healthy homes standards if renting, and insurance coverage.

Can it be attached to my house?
The cleanest pathway is a detached minor dwelling. If you’re thinking attached or above-garage, get professional advice to stay within the “simple design” intent.

What size works best?
Most families land between 45–60m² for a 1–2 bedroom layout. You can go to 70m² if your site and budget allow.

The big picture

This reform won’t solve the housing crisis on its own—but it does give everyday homeowners a practical way to create warm, code-compliant homes for whānau or rental, without months of consenting. It’s a small change with meaningful impact—especially for multi-generational living, accessibility, and regional/rural housing needs.