Getting Started

To get started with your BASIX assessment you will need to log in to the BASIX assessment tool - available on the right hand side of this website. If a first time user you will need to create an account.

Once you have logged in to the BASIX assessment tool you will be asked for project details and information relating to the proposed design - whether it be a single dwelling, multi-dwelling or alteration and addition.

To see what an ideal BASIX project looks like and to view checklists of information required to complete the BASIX assessment, visit the relevant building type section below:

Language assistance

If you or someone you know needs Language assistance we have several BASIX
fact sheets available in other languages to assist you:

 Read BASIX fact sheets in other languages


If you are having trouble using the BASIX assessment tool or have an urgent enquiry please contact the BASIX helpdesk. Contact details are available in the Support section of this website.

Which BASIX tool suits my project?

Depending on your project, there are three BASIX online assessment tools:

  • new dwellings – single dwelling houses
  • new dwellings – multi-dwellings
  • alterations and additions

There is also an administration tool for certifiers and planners.

New dwellings – single dwelling houses

This tool allows registered users to generate a BASIX certificate for a new single dwelling - typically class 1 building in the National Construction Code.

In most cases this will be a detached dwelling house, but can also include:

  • one dwelling in a conjoined or semi-detached house where the dwelling is on a separate land title with no common property or shared services.
  • one of several similar dwelling houses, each of which is on a separate land parcel, such as in a new subdivision. The 'duplicate' function in the project portfolio allows individual certificates to be quickly generated for each similar dwelling house.
  • a change of use (conversion) from a non-residential building, or from a structure that is not approved to be used as a dwelling, to a dwelling house. In this situation, advice may need to be obtained from the BASIX help desk as to how project details are entered in the tool, and whether an alternative assessment is required for any part of the existing structure
  • a secondary dwelling that involves converting non-habitable space (such as a garage) or new construction outside the footprint of the existing (primary) dwelling.

View more information on using BASIX for secondary dwellings.

New dwellings – multi-dwellings

This tool allows registered users to generate a BASIX certificate if the project involves more than one dwelling, or the development includes common property or services shared with other new or existing development. Typical project types include:

  • a residential flat building - generally three or more units to be strata titled (typically class 2 buildings in the National Construction Code)
  • two or more terrace houses, row houses or semi-detached houses, with or without common property or shared services
  • two or more detached or attached houses, including villa units and dual occupancy dwellings on one parcel of land with common property and/or shared services
  • several single dwellings on land subject to subdivision to create new separate lots.

For more information on using BASIX for subdivision projects and large, multi-unit developments, refer to the help note on When is more than one BASIX certificate required?

Note that the DIY method for thermal comfort assessment cannot be used for multiple dwellings. An accredited assessor is required to complete the thermal comfort section using software accredited by the Nationwide House Energy Rating Scheme (NatHERS).

Alterations and additions, and pools and spas

This tool allows registered users to generate BASIX certificates for the following purposes:

  • to alter, enlarge or extend an existing BASIX-affected building
  • for a swimming pool or spa, or combination of swimming pools and spas, that serve only one dwelling.

The tool can also be used to generate a BASIX certificate for a secondary dwelling where that dwelling is created by converting existing habitable space within the primary dwelling. View more information on using BASIX for secondary dwellings.

Administration tool

This tool allows certifiers and council planners to search, access and check already generated BASIX certificates. Accredited certifiers can also generate BASIX completion receipts. The administration tool is not available to general users.

Dwelling types

BASIX categorises projects for assessment into three distinct residential building types:

Definitions of these dwelling types can be found in our BASIX definitions. If you are unsure which BASIX residential building type applies to your project, you may need to show your building plans to the council or PCA.

Example residential dwellings and BASIX building type

Single dwellingMulti dwellingAlteration and addition
Single house on one lot Townhouse Addition to existing house
Bungalow Row house Swimming pool
One part of semi-detached home Terrace Basement or an attic
Cottage Residential flat building Sunroom
Secondary dwelling (Granny flat)   
(change of use or next to existing principal dwelling)
Dual occupancy Spa room
  Two houses on one lot Sauna
  Shoptop house  Secondary dwelling (Granny flat)
(conversion of existing habitable space)
  A new principal dwelling and a new Secondary dwelling (Granny flat)     


A council or certifying authority may consider that an "Exhibition home" or "Display home", despite its short-term use as a sales office or other non-residential purposes, is capable of being sold and occupied as a dwelling. If so, BASIX will apply to the "Exhibition home" or "Display home".