If you want to use a building, or part of a building, for a different purpose than it’s used for now, you must tell us in writing. This applies even if you’re not planning any building work.

You can’t start using the building for its new purpose until we’ve confirmed in writing that the new use meets the Building Act and building code.

What “building use” means

Every building has a lawful use. This use sets the building code requirements the building must meet so it’s safe, healthy, and suitable for the people using it.

If the use changes, the building may need upgrades or alterations to meet the requirements for its new purpose.

Building uses are grouped into four main categories:

  • Crowd activities – places where people gather (eg theatres, halls, places of worship).
  • Sleeping activities – places where people sleep (eg homes, motels, care facilities).
  • Working, business or storage activities – places used for offices, shops, factories, warehouses and similar.
  • Intermittent activities – buildings that are used occasionally or for short periods (eg garages, some utility buildings).

These groups are divided into 15 specific building use categories. You can find definitions and examples in Schedule 2 of the Building (Specified Systems, Change the Use, and Earthquake-prone Buildings) Regulations 2005.

Understanding a building's current and proposed use is an important part of determining whether a change of use has occurred, and what building code requirements apply.

When it’s a change of use

It’s a change of use when both of these apply:

  • the use of a building, or part of it, moves into a different use category, and
  • the new use has extra or stricter building code requirements than the current use.

For example, turning a warehouse into offices, or converting commercial space into a home, may be a change of use.

How to tell us

Before you change how a building is used, send us:

A fee applies – see our fees and charges.

Your application needs enough information, reports, and supporting documents to show how the building will meet Section 115 of the Building Act 2004.

For applications, you’ll need to show how the building will meet building code requirements for:

  • fire safety, including escape routes, fire separation, and protection of neighbouring properties.
  • sanitary facilities.
  • structural strength and stability.
  • access and facilities for people with disabilities.

Clear, complete, and well-organised information helps us process your application faster and can reduce your costs.

How we access your application

A building surveyor will assess your application, with help from any specialists if needed for your project.

Most applications are processed within 20 working days. More complex applications may take longer.

We will:

  • tell you about any other approvals that may be required (eg resource consent or building consent).
  • decide whether your proposal is a change of use under the Building Act 2004.
  • check whether the building will meet the building code requirements for the new use “as nearly as is reasonably practicable (ANARP)”.
  • tell you about any upgrades needed.
  • give you our decision in writing.

“As nearly as is reasonably practicable (ANARP)” means we weigh up the benefits of upgrading the building against the cost, difficulty, and practical impact of meeting current requirements in full. We then decide whether the level of compliance you’re proposing is reasonable.

Our decision

We’ll tell you in writing whether:

  • your proposal isn’t a change of use and doesn’t need our approval.
  • we’re satisfied the building will meet the requirements for its new use, or
  • we can’t approve the change of use because we’re not satisfied the building will meet the requirements.

If the building is already being used for the new purpose, we may issue a notice to fix.

If you don’t tell us

If you change the use of a building without telling us in writing first, you may be fined up to $5,000.

If building work has been done without the required approvals, we may also issue an infringement notice or a notice to fix.

If a buildings classified use has already changed, we may ask for more information, assessments, or upgrade work before we can be satisfied the building is suitable for its new use.

To avoid delays, extra costs, and enforcement action, contact us before you change how your building is used.

For more information see MBIE’s guidance on change of use.