The EP&A Regulation states that an application need only be accompanied by one BASIX certificate except "if the proposed development involves the alteration, enlargement or extension of a BASIX affected building that contains more than one dwelling, a separate BASIX certificate is required for each dwelling concerned."
This is because each component of any BASIX affected work being undertaken to an existing dwelling must pass a minimum requirement for water and energy efficiency and these requirements cannot be combine into a common 'score' covering the entire development.
Where the application is for new dwellings, the application need only be accompanied by one BASIX certificate, however, a number of certificates maybe required, or maybe desirable, in some circumstances.
Subdivision into single 'Torrens title' lots.
Where the development includes land subdivision into separate lots as well as construction of detached single dwellings (class 1 buildings) on those lots and does not involve any common property or shared services, the application may be accompanied by either one BASIX certificate covering all dwellings, or by individual BASIX certificates for each dwelling.
A single BASIX certificate covering all dwellings can be produced using the BASIX Multi-dwelling tool. For large subdivisions, this reduces the number of certificate pages by grouping the BASIX commitments for each dwelling in tables. However, this may create procedural complications for the applicant and approval authority later in the development cycle when revisions are made to parts of the application, particularly where land parcels are on-sold, or constructed by different sub-contracting builders.
In these cases, an individual BASIX certificate, or grouped certificates, may offer more long term flexibility for the applicant and approval authority, allowing revisions to the original Basix Certificate(s) to each individual dwelling.
The most suitable approach for a particular development is best determined in consultation with the consent authority (local council).
Development involving strata title.
Development for residential flat buildings, villa units, multi-dwelling houses, dual occupancy or mixed use development on land that includes common property, shared services or shared facilities should be accompanied by one certificate covering the entire development. This allows for proper apportionment of water and energy demands attributable to common property or shared central services and allows for clearer administration, with one certificate applying to the entire strata plan.
An exception to this is some larger developments and projects requiring staged or phased construction.
In some cases, the nature of the development requires division into separable parts for the purpose of part consent, staged construction or for easier management of each part or class of the development.
In such circumstances, you should first consult with the BASIX help desk to establish whether the project is suitable for division into separable parts and how common areas and shared services should be apportioned between those parts.
Large multi-building residential flats
Development involving a number of separate residential 'towers' or blocks with more than 600 units overall, may require more than one BASIX certificate to enable faster calculation of the BASIX score and allow easier management of future revision for each tower or block. In such circumstances, you should first consult with the BASIX help desk to establish whether the project is suitable for division into separable parts and how common areas and shared services should be apportioned between those parts.
To assist the help desk with providing a response, your enquiry should be accompanied by plans and description of the proposed development, and a proposal for how common property and shared services might be apportioned.
Note: Certificates generated prior to 1 July 2017 are limited to 200 units. To add more dwellings to these projects, please contact the BASIX help desk.