Building and renovating a home

Introduction

This section has information to help you build or renovate a residential property in the Northern Territory (NT).

You can also read about building and renovating permits and processes.

For more information, read the building and renovating in the NT consumer guide PDF (16.1 MB).

To help you prepare for your building project and guide you before signing a contract for the project, use the building and renovating in the NT checklists PDF (1.3 MB).

To help you learn about tropical design features and how to keep your house cool, read a guide to designing homes for the Top End climate PDF (8.0 MB).

To find out more about building rules and regulations, contact Building Advisory Services.


Extending or renovating your home

This page has information about your options when extending or renovating your home.

Planning your work

Depending on the legal responsibilities and involvement you want, you can choose to extend or renovate your home in any of the following ways:

  • use a company that manages your plans, building permits and construction
  • use a separate designer and building company
  • use a design and build company
  • engage a builder to supervise your project and coordinate subcontractors
  • become an owner-builder.

Legal requirements

Find out what is required for your project by checking the list of residential building work that requires permits.

Speak to a building certifier to find out about legal requirements or exemptions specific to your project. Read about engaging a registered building certifier.


Residential building work that requires permits

This page has information about the permits and processes for residential construction projects in the Northern Territory (NT).

Common residential building projects in the NT

Check the table below for your legal requirements.

Building work

Building permit

Building contract

Fidelity fund insurance

Registered building contractor

Other requirements

New house and attached or associated structures constructed at the same time as a new house - eg: carport, verandah, garden shed

Required

Required

Required

Required


Relocating an existing house to a new location

Required

Required

Required

Required

Read Building Note 100 - Relocation of existing houses to approved rural land PDF (373.9 KB)

Renovating a bathroom - changing walls, fixtures and plumbing

Required

Recommended

Not required

Not required

Read renovating and refurbishing wet areas

Renovating bathroom - no change to walls, fixtures and plumbing

Not required

Recommended

Not required

Not required

Read renovating and refurbishing wet areas

Alterations or extensions to an existing house - increases floor area

Required

Required

Required

Required


Alterations to an existing house - no increase in floor area

Required

Recommended

Not required

Not required


Existing house - changing windows, reroofing or replacing sheeting

Required

Recommended

Not required

Not required


Additions to existing house - skylight, roof vents or a satellite dish

Required - some exemptions apply

Not required

Not required

Not required

Read about exemptions for satellite dishes, skylights and roof ventilators

Solar hot-water systems

Required

Recommended

Not required

Not required

Read Building Note 56 - Solar hot water heaters installation policy PDF (131.9 KB) and Building Note 63 Installation of solar hot water heaters on multinail truss systems PDF (242.2 KB)

Solar photovoltaic installations

Required

Recommended

Not required Not required

Read Building Note 81 Solar photovoltaic installations PDF (1019.0 KB) and Building Note 83 Solar voltaic installations - non cyclonic regions PDF (50.2 KB)

Carport or verandah addition to an existing house

Required

Recommended

Not required

Not required


Garden shed or workshop

Required - some exemptions apply

Recommended

Not required

Not required

Read about exemptions for building a garden shed, carport, fence or shade structure

Pergola or shade structure

Required - some exemptions apply

Recommended

Not required

Not required

Read about exemptions for building a garden shed, carport, fence or shade structure

New fence or renovate an existing fence

Required - some exemptions apply

Recommended

Not required

Not required

Read about exemptions for building a garden shed, carport, fence or shade structure

New retaining wall - supporting building work

Required

Required

Required

Required


New retaining wall - not supporting building work

Required if over 600mm in height

Recommended

Not required

Not required


Swimming pools

Not required

Recommended

Not required

Not required

Read about installing safety barriers when you install a pool or spa

Building control areas and certification requirements

If your property is in a building control area and the table above shows that you need a building permit, you must get building certification for the work from an NT registered building certifier.

Read about the building certification process and engaging a registered building certifier.

The location of your property, in either a Tier 1 or Tier 2 building control area, will determine whether you need full or part building certification.

The two-tier system in the NT means fewer permits and paperwork are needed if your building work is in a Tier 2 area - outside of the Darwin, Lake Bennett and Alice Springs regions.

Read more about building control areas.

Building or renovating in a Tier 1 area

If you need a building permit, you must engage an NT registered building certifier for full building certification, including getting occupancy certification at the end of the construction process.

Building or renovating in a Tier 2 area

If you need a building permit, you must engage an NT registered building certifier,but you may only need part building certification.

For building work on townhouses and apartments in Tier 2 areas, you must follow the full building certification process including construction inspections and the issue of an occupancy permit.

Part building certification

Part building certification only applies for work on the following types of buildings in Tier 2 areas:

  • a detached house or single dwelling
  • a garage, carport or shed attached to and built at the same time as a detached house
  • a retaining wall - built at any time - not attached to a house, townhouse or flats, but which will support such a building.

To comply with part certification, you must have a building permit before starting construction. On completion, your builder must sign a legal declaration stating the work has been done in line with the permit.

During construction however, your building certifier does not need to conduct construction inspections and you do not need an occupancy permit at the completion of work.

You must still get any documentation prescribed by law, such as building work certificates from tradesmen for plumbing, glazing, electrical, termite treatment, prefabricated roof trusses, prefabricated window and door frames, wet area sealing products, and fire safety products or installations. Your building certifier can tell you which documents you need.

You must also meet legal requirements for building contracts, registered building contractors and fidelity fund insurance for your work.

If a builder’s declaration is not available

If you are not able to obtain a builder’s declaration for work in a Tier 2 area that would otherwise only require that declaration to complete the certification, you must contact your building certifier.

Your building certifier may be able to carry out extra assessments and grant a certificate of substantial compliance or certificate of existence for the work.


Residential building work that requires a registered builder

This page has information about when you must use a registered builder for residential building work in the Northern Territory (NT).

When you must use a registered builder

You must use a registered builder for prescribed residential building work. Find out what is prescribed building work

New builds

When you construct a new home you must:

  • use a registered building contractor - either a building contractor residential (restricted), or a building contractor (unrestricted) 
  • or become registered as an owner builder.

For buildings of three storeys or more, you must employ a building contractor residential (unrestricted).

Extensions and renovations

You may need to use a registered building contractor for your renovation or extension. 

Check the table of residential building work that requires permits to see if you need a registered building contractor.

Finding a builder

Read about choosing a builder or contractor.

Becoming an owner builder

You may choose to become a registered owner builder. Find out how to get an owner builder certificate.

Owner-builders can't construct, extend or renovate duplexes, townhouses, flats or units.


What is prescribed residential building work

This page has information on building work in the Northern Territory that is prescribed by law. 

If your building work is prescribed, you must use a registered builder or contractor.

Your building work is considered prescribed if it's worth more than $12,000 and involves one of the following buildings:

  • a class 1a building, for example a single dwelling, a detached house or attached townhouses or duplexes
  • a class 2 building, for example attached units or flats
  • extensions and renovations to class 1a or class 2 buildings where the floor area is increased
  • a class 10 building - for example a garage, carport or shed - attached to and built at the same time as a class 1a or class 2 building
  • a retaining wall - whenever built - that is not attached to a class 1a or class 2 building but on which the integrity of such a building depends
  • the relocation of an existing building.

Requirements of prescribed work

You must use a registered building contractor for prescribed building work. Read about choosing a builder or contractor.

You must sign a contract with your builder for prescribed building work. Read about signing a residential building contract.


Signing a residential building contract

This page has information about when you must have a residential building contract in the Northern Territory (NT) and what it must include.

Once you find a builder that you trust, and are satisfied with their quote, you must sign the contract before work begins. 

When you need a residential building contract

Check if you need a residential building contract by reviewing the list of residential work that requires permits.

While you only need a building contract under NT law for prescribed residential building work, written contracts for all your building work may be useful if you need to review your builder’s work later on.

What your residential contract must include

A residential building contract for prescribed works must meet specific requirements under the Building Act.

The contract must specify all of the following:

  • the building contractor’s details and registration number
  • the extent of the work to be undertaken
  • the total contracted price
  • the schedule of progress payments, either the standard schedule or an alternative schedule agreed between you and the builder and documented as a formal agreement on the appropriate forms - see more information below
  • a provision about dispute resolution
  • the consumer guarantees required by the Building Act
  • the applicable building standards of work - if higher than the National Construction Code and Australian Standards.

A standard schedule of progress payments

A standard schedule for progress payments for a residential building contract should look like the following:

  • deposit before commencement - no more than 5% of the total contracted price
  • on completion of base stage - no more than 10% of the total contracted price
  • on completion of frame stage - no more than 20% of the total contracted price
  • on completion of enclosed stage - no more than 25% of the total contracted price
  • on completion of fixing stage - no more than 30% of the total contracted price
  • at practical completion - no more than 7% of the total contracted price
  • final completion - at least 3% of the total contracted price after issue of  occupancy certification, or a builder’s declaration in a Tier 2 area.

Carefully consider whether your project requires an alternative payment schedule before agreeing on any changes with your building contractor.

Before you sign a contract

Your residential building contract is a binding legal document. It details how you and your builder will share rights and responsibilities for the project.

Before you sign the contract, you should understand the construction process for your project, the steps along the way, the variables that can occur and how to resolve issues if they arise.

You need to be aware of what is in your contract. 

If there are any changes or variations to the project during construction, make sure these are in writing and the contract is changed as needed.

If you are unsure about a contract, get legal advice before you sign it.