A small backyard patio with wooden deck, wooden fence, and open door leading into a house with a kitchen visible through a window.

Granny Flats / Minor Dwellings – Kāpiti Coast & Wellington

fewer inspections, faster approvals, and lower costs

View of a bathroom with a white sink vanity and a mirror, open door leading to a kitchen with a window and wooden flooring.
Get a Quote
Small wooden house with an open door and window, wooden deck, surrounded by a wooden fence, on a sunny day with blue sky.

2. The Golden Rules: When You Don’t Need Building Consent

Height / Boundary

  • Single storey only

  • Floor level max 1m above ground

  • Total height max 4m above floor level

  • Minimum 2m from boundaries

  • Minimum 2m from any other residential building on site

Miss one rule and you’re back into full consent.

No mezzanines. No loft conversions.

Table of Contents

  1. What Has Actually Changed?

  2. The Golden Rules: When You Don’t Need Building Consent

  3. Designing It Properly (Not Just Dropping a Box in the Backyard)

  4. The Common Mistakes That Will Cost You

  5. The Paperwork You Still Need (Yes, There Is Some)

  6. Should You Still Get Building Consent?

1. What Has Actually Changed?

You may have heard:
“Granny flats under 70m² don’t need consent anymore.”

That statement is only partially true.

The government introduced an exemption for Small Stand-alone Dwellings up to 70m². This allows homeowners in Wellington and the Kapiti Coast to build a secondary dwelling without going through the full building consent process — provided every exemption condition is met.

This can work well for:

  • Multigenerational living

  • Independent space for family members

  • Home offices

  • Rental income

  • Downsizing solutions

However, exemption does not mean no standards.

The building must still:

  • Comply with the NZ Building Code

  • Be built or supervised by Licensed Building Practitioners (LBPs)

  • Meet strict size, height, material and boundary requirements

Responsibility shifts from Council oversight to you and your builder.

That means you need the right builder.

Size

  • Maximum 70m² floor area

  • Includes any attached garage

  • No flexibility — 70.1m² triggers consent

Stand-Alone Structure

  • Must be fully detached

  • Cannot connect to your main dwellin

  • Lightweight timber or steel framing

  • Roof cladding max 20kg/m² (e.g. long-run metal)

  • Wall cladding max 220kg/m² (e.g. timber weatherboards)

3. Designing It Properly — Not Just Dropping a Box in the Backyard

Many “granny flats” look temporary.

At Keen Builders, we approach them as permanent architectural additions to your property.

We specialise in renovations and character work, so even under exemption rules, we can design a secondary dwelling that:

  • Matches your existing home’s proportions

  • Uses timber weatherboards to complement villa or bungalow styles

  • Aligns roof pitch and window proportions

  • Feels intentional — not like a transportable cabin

For Kapiti Coast and Wellington properties, especially character homes, this matters. A well-designed minor dwelling increases value. A poorly designed one can detract from it.

If you're investing $200k–$300k+, it needs to look like it belongs.

4. What You Definitely Can’t Do (Common Pitfalls)

This is where homeowners get caught out.

Under the exemption rules, you generally cannot:

Install a Wet-Floor Tiled Shower

You must use a pre-fabricated shower unit.
Custom tiled, level-entry showers typically require consent due to waterproofing risk.

Use Heavy Cladding or Roofing

Concrete tiles and heavy masonry systems usually exceed weight limits.

Install a Wood Burner

Solid fuel fireplaces still require building consent.
Electric and some gas heating options are acceptable.

Build on Hazard-Prone Land

If your property is subject to:

  • Flooding

  • Slip risk

  • Coastal hazard

  • Significant ground movement

You will likely require consent.

In Wellington and parts of Kapiti, this is a serious consideration.

5. The Paperwork You Still Need

Even without building consent, you are not avoiding documentation.

You still require:

Project Information Memorandum (PIM)

Before starting, apply to Council for a PIM.
This identifies:

  • Natural hazards

  • Infrastructure constraints

  • Planning restrictions

  • Heritage overlays

Completion Documentation

At the end of the build, you must provide:

  • Final design plans

  • Records of Work (LBP documentation)

  • Electrical safety certificates

  • Plumbing and drainage compliance

  • Gas certification (if applicable)

You cannot legally DIY restricted building work.

6. Should You Still Get Building Consent?

In many cases — yes.

If you want:

  • A tiled wet-area bathroom

  • Architectural detailing

  • Higher ceilings

  • Complex roof forms

  • Polished concrete floors

  • Integrated structural design

  • Design flexibility

Then full building consent may be the better pathway.

The exemption is ideal for simple, compliant, rectangular dwellings.

But if you’re building a long-term asset, sometimes the extra design freedom is worth it.

Considering a Granny Flat in Wellington or Kapiti?

At Keen Builders Ltd, we specialise in:

  • High-quality renovations

  • Architectural additions

  • Structurally sound builds

  • Clear, professional project management

We can:

  • Assess whether your site qualifies

  • Advise whether exemption or consent is smarter

  • Design something that adds genuine value

  • Provide realistic cost planning before you commit

Contact Keen Builders Ltd

Brae Burrows-Keen
Director

Kapiti Coast & Wellington Region

Email: burrowskeen.limited@gmail.com
Phone: 022 490 0869
Instagram: @keen_builders