Answer first: On NSW Class 2 apartments (and mixed-use buildings with a Class 2 part), registered design practitioners prepare regulated designs and design compliance declarations, the registered building practitioner lodges those documents on the NSW Planning Portal and later makes the building compliance declaration, an optional principal design practitioner can coordinate the design suite, and an appropriate practitioner may lodge design packages for the builder—while professional engineers declare engineering work within their discipline.
By Franz Phan, Registered Design Practitioner (Class 2), giantA Pty Ltd
For developers, investors, builders and strata / owners corporations, Class 2 delivery is no longer a hand-off from “architect to builder”. Under the Design and Building Practitioners Act 2020 (DBP Act), collaboration is statutory: regulated designs must integrate across disciplines, be declared, and be lodged before relevant building work starts. This guide explains who does what, how the Planning Portal workflow fits together, and where to confirm current NSW rules.
Disclaimer: This article is general information for NSW projects, not legal advice. Always confirm obligations, exclusions and commencement dates on nsw.gov.au, the NSW Planning Portal and legislation.nsw.gov.au.
What does Class 2 design collaboration mean under the DBP Act?
Class 2 buildings are typically multi-storey, multi-unit apartment buildings where people live above or below each other. Class 2 can also include a single-storey attached dwelling over a common space such as a carpark or basement. Mixed-use buildings that include a Class 2 part are also caught where the scheme applies.
NSW Government guidance states that Class 2, Class 3 and Class 9c buildings are currently regulated under the Design and Building Practitioners scheme. The scheme began with Class 2 (and buildings with a Class 2 part). From 3 July 2023 it expanded to certain new Class 3 and 9c buildings (and buildings with those parts). Alteration, repair or renovation work on existing Class 3 and 9c buildings is scheduled to be subject to the DBP legislation from 1 July 2028. The DBP Act continues to apply to building work on new and existing Class 2 buildings.
Collaboration under the DBP Act means each registered practitioner owns a defined package of regulated designs and declarations, while the project team keeps those packages coordinated so the declared design set remains buildable and Code-compliant. Isolation is not acceptable: NSW guidance expects design practitioners to integrate other aspects of the work and other regulated designs prepared by other registered practitioners.
Who are the key practitioners on a Class 2 apartment project?
What does a registered design practitioner (RDP) do?
A design practitioner prepares regulated designs and makes design compliance declarations. Regulated designs are required when building work on a Class 2, 3 or 9c building involves a building element or a performance solution (subject to exclusions in the DBP Regulation). For Class 2, this applies to new and existing buildings.
Design compliance declarations confirm, among other things, that the design complies with the Building Code of Australia (BCA) as it sits within the National Construction Code (NCC), and that the design integrates with other relevant designs for the work. Only the person who will declare or lodge documents needs to register for that function—for example, one practitioner may sign off designs prepared by a team.
Registration classes are specialised (architectural, building design, fire systems, drainage, vertical transportation, and others). Practitioners must stay within the class they hold. For Class 2 apartments, teams commonly include architectural / building design practitioners plus discipline specialists for structure, fire systems, waterproofing interfaces and other building elements.
Related reading: Registered Design Practitioner vs Architect: who can design Class 2 buildings in NSW.
What does the registered building practitioner do?
The building practitioner is the person (individual or body corporate) who agrees to do or oversee the building work, or the principal contractor where more than one builder is involved. There is only ever one building practitioner for a project.
Core responsibilities include:
- Ensuring all regulated designs and design compliance declarations are lodged on the NSW Planning Portal before any building work relevant to those designs is carried out
- Making the building compliance declaration that building work has been constructed in accordance with the declared designs and otherwise complies with the BCA
- Lodging the building compliance declaration and any as-built designs on the Planning Portal before an occupation certificate application
Building practitioner registration can be general, low-rise or medium-rise, or held by a body corporate with a nominated individual. Restricted classes limit the buildings on which that practitioner may declare and lodge.
When should you appoint a principal design practitioner (PDP)?
A principal design practitioner is optional. NSW guidance describes the role as suited to larger, more complex projects where many regulated designs and declarations must be coordinated and lodged.
Where appointed, a PDP coordinates design practitioners’ work and provides a principal compliance declaration for the registered building practitioner. To register as a PDP you must already be registered as a design practitioner—but not every design class is eligible.
PDP exclusions: practitioners registered only in building design (low-rise), building design (medium-rise), drainage (restricted), or vertical transportation cannot elect to be principal design practitioners.
Appointing a PDP does not remove each design practitioner’s duty to prepare and declare their own regulated designs. It adds a coordination and principal-declaration layer that can reduce lodgement friction on multi-discipline Class 2 jobs.
What is an appropriate practitioner?
An appropriate practitioner is a registered design practitioner or principal design practitioner working on the same project who can lodge designs, documents and design compliance declarations on behalf of the building practitioner on the NSW Planning Portal.
Critical limit: an appropriate practitioner cannot make or lodge the building compliance declaration. Only the building practitioner can do that. See sections 16 and 17 of the DBP Act and NSW’s roles guidance.
In practice, nominating an appropriate practitioner (often the lead RDP or PDP) keeps design lodgement moving while the builder retains sole ownership of the final building compliance declaration.
Where do professional engineers fit?
Professional engineers who perform professional engineering work for regulated buildings must be registered under the DBP scheme for the relevant engineering class. Their designs and declarations sit alongside architectural / building design packages. Structural, fire safety, hydraulic and other engineering packages must be integrated into the regulated design set before relevant work starts—not treated as “shop drawings later”.
How do roles map to Planning Portal lodgement?
| Role | Primary duty | What they lodge / declare | Can they lodge for the builder? |
|---|---|---|---|
| Registered design practitioner | Prepare regulated designs; integrate with other designs | Design compliance declaration for their package | Yes, if nominated as appropriate practitioner |
| Principal design practitioner (optional) | Coordinate design suite | Principal compliance declaration | Yes, if nominated as appropriate practitioner |
| Building practitioner | Ensure lodgement before work; oversee construction to declared designs | Building compliance declaration; as-built designs before OC | N/A — owns builder lodgement pathway |
| Appropriate practitioner | Lodge design packages for BP | Designs and design compliance declarations only | Yes — design lodgement only |
| Professional engineer | Professional engineering work in registered class | Engineering designs / declarations as required | Only if also holding a qualifying design / PDP registration and nominated |
| Registered certifier | Independent certification oversight | Must have required declared designs before CC/CDC; OC gated on declarations | No — not a substitute for BP lodgement |
NSW Planning Portal developer and practitioner resources explain how to upload and manage design and building practitioner documents. Use the official support materials rather than informal email trails as your audit record: Planning Portal — developer and practitioner resources.
Related reading: Class 2 building compliance documentation: what developers must lodge on the NSW Planning Portal.
What is the typical Class 2 collaboration workflow?
- Confirm the building is regulated. Class 2 and mixed-use with a Class 2 part are in scope for new and existing work. Check Class 3 / 9c commencement rules and any low-risk exemptions before scoping fees and program.
- Map registration classes to building elements. Assign architectural / building design and each specialist package (structure, fire systems, waterproofing interfaces, vertical transportation, drainage, and so on) to a registered practitioner authorised for that work.
- Decide whether to appoint a PDP. Useful where many packages and frequent variations will hit the Portal; confirm the candidate is eligible (not in an excluded class).
- Produce integrated regulated designs. Each RDP designs for BCA compliance and integration—not siloed drawings.
- Issue design compliance declarations. Declarations travel with the design packages.
- Lodge before relevant building work starts. The building practitioner, or an appointed appropriate practitioner, lodges on the Planning Portal. Work must not start ahead of lodgement for the designs that relate to that work.
- Manage mid-build variations. Changed regulated designs generally need updated designs and declarations and re-lodgement before the varied work proceeds. See Class 2 design variations mid-build: DBP Act rules for NSW apartment sites.
- Building compliance declaration and as-builts. Before occupation certificate application, the building practitioner lodges the building compliance declaration and any as-built designs. Certifiers cannot issue an OC until required declarations and documents are in place.
For a broader Class 2 compliance overview, see Class 2 apartment building design NSW 2026: DBP Act compliance guide.
How should developers, builders and strata structure collaboration?
- Developers / investors: Put registration, lodgement milestones and variation protocols in consultant and builder appointments. Treat Planning Portal status as a hold point equal to DA/CC conditions.
- Builders: Confirm you are (or your company nominee is) the registered building practitioner for the job. Decide early whether lodgement will be done in-house or delegated to an appropriate practitioner. Never assume design lodgement equals permission to skip the building compliance declaration.
- Strata / owners corporations: For remedial Class 2 work, expect the same practitioner registration and Portal discipline as for new apartments. Ask for evidence of lodged declarations before approving major building-element works.
What exclusions and staging traps should teams watch?
NSW guidance lists work excluded from DBP obligations (for example certain exempt development other than waterproofing, and other categories in clause 13 of the Design and Building Practitioners Regulation 2021). From 1 July 2024, certain low-risk Class 3 buildings and Class 9 buildings containing a minor Class 3 part may be exempt from DBP requirements—hotels and motels only where no part is subject to a strata scheme or contains serviced apartments, among other conditions. Do not assume a Class 2 apartment tower enjoys those Class 3 exemptions.
Certifiers remain independent: they must ensure required regulated designs and design compliance declarations are available before issuing a construction certificate or complying development certificate, and they cannot issue an occupation certificate until required compliance declarations for the building work are lodged.
How can giantA help on Class 2 RDP collaboration?
giantA Pty Ltd provides Class 2 registered design practitioner services and coordinated design documentation for NSW apartment and mixed-use projects—helping developers and builders align regulated designs, declarations and Planning Portal lodgement pathways. Contact giantA for Class 2 RDP / design documentation support tailored to your site. We do not publish fixed fees here; scope and program drive each fee proposal.
FAQ: Class 2 design collaboration under the DBP Act
Is a principal design practitioner mandatory on Class 2 projects?
No. A PDP is optional. NSW describes the role as particularly useful for larger, more complex projects with many designs to coordinate and lodge.
Can an appropriate practitioner make the building compliance declaration?
No. Only the registered building practitioner can make and lodge the building compliance declaration. An appropriate practitioner may lodge designs and design compliance declarations only.
Do Class 2 alterations and renovations need regulated designs?
Where the work is regulated building work involving a building element or performance solution, yes—NSW guidance confirms the DBP Act continues to apply to building work on new and existing Class 2 buildings, subject to listed exclusions.
When do existing Class 3 and 9c alterations enter the scheme?
NSW Government guidance states alteration, repair or renovation work on existing Class 3 and 9c buildings will be subject to the DBP legislation from 1 July 2028. Certain new Class 3 and 9c work has been covered since 3 July 2023.
Who lodges regulated designs on the NSW Planning Portal?
The registered building practitioner, or an appointed appropriate practitioner (a registered design practitioner or principal design practitioner on the same project).
Which design practitioners cannot become a PDP?
Building design (low-rise), building design (medium-rise), drainage (restricted) and vertical transportation design practitioners cannot elect to be principal design practitioners.
Is there only one building practitioner per project?
Yes. NSW guidance states there is only ever one building practitioner for a project—either an individual or a body corporate (with nominee arrangements where applicable).
Where should I confirm current rules?
Use Building classes and roles, the design and building obligations pages on nsw.gov.au, Planning Portal practitioner resources, and the in-force DBP Act / Regulation on legislation.nsw.gov.au.
Sources: NSW Government — Building classes and roles; Design practitioner obligations; Building practitioner obligations; NSW Planning Portal developer/practitioner resources; Design and Building Practitioners Act 2020 (NSW); Design and Building Practitioners Regulation 2021; National Construction Code / Building Code of Australia.
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