Answer first: Under the NSW Design and Building Practitioners Act 2020, a regulated design is a design prepared for a building element or a performance solution on Class 2 (and other regulated) building work. A registered design practitioner must provide a Design Compliance Declaration when that design is construction-ready. The registered building practitioner (or nominated appropriate practitioner) must lodge those designs and declarations on the NSW Planning Portal before the related building work starts.
By Franz Phan, Registered Design Practitioner (Class 2), giantA Pty Ltd
For developers, investors, builders and strata managers delivering NSW apartments, the practical question is not only “who is the RDP?” — it is which building elements trigger regulated designs, when Design Compliance Declarations (DCDs) must exist relative to construction, and how those declarations sequence with the building practitioner’s Portal lodgement. This guide is an inventory and sequencing tool, distinct from role mapping and mid-build variation rules covered elsewhere on giantA.
Disclaimer: General information for NSW projects, not legal advice. Confirm current obligations, exclusions and forms on nsw.gov.au, the NSW Planning Portal, NSW Fair Trading and legislation.nsw.gov.au.
What is a regulated design under the DBP Act?
Section 5 of the DBP Act defines a regulated design as:
- a design prepared for a building element for building work; or
- a design prepared for a performance solution for building work (including a building element); or
- any other design class prescribed by the regulations.
NSW Government guidance confirms regulated designs apply when building work on a Class 2, 3 or 9c building (including mixed-use with those parts) involves a building element or a performance solution — subject to exclusions in the Design and Building Practitioners Regulation 2021. For Class 2, the scheme applies to new and existing buildings.
A Design Compliance Declaration is the registered design practitioner’s formal statement that the regulated design complies with the Building Code of Australia (BCA / NCC), meets other applicable requirements, and (as far as reasonably practicable) integrates with other relevant designs for the work. Declarations must use the approved forms published by NSW Fair Trading. From March 2023, a separate DCD is required for each regulated design — the old multiple regulated design form is no longer accepted.
Related reading: Class 2 design collaboration NSW: RDP, building practitioner and PDP roles and Class 2 apartment building design NSW 2026: DBP Act compliance guide.
Which building elements trigger regulated designs on Class 2 apartments?
Section 6 of the DBP Act sets out what counts as a building element. NSW guidance summarises these categories for practitioners. Use the table below as a project inventory checklist — then map each package to a registered design practitioner authorised for that class of work.
| Building element (DBP Act s 6 / NSW guidance) | Typical Class 2 apartment packages | Usually needs regulated design + DCD? |
|---|---|---|
| Fire safety systems (including passive fire) within the meaning of the BCA | Active systems (detection, sprinklers, smoke control where required); passive fire (FRLs, fire walls, shafts, fire doors, penetrations) | Yes, where building work involves those systems |
| Waterproofing | Wet areas, balconies, podiums, planter interfaces, roof membranes tied to enclosure | Yes for regulated waterproofing work (note limited exclusions for some single-dwelling bathroom/kitchen/laundry/toilet work — check Regulation carefully) |
| Internal or external load-bearing components essential to stability | Foundations/footings, floors, walls, roofs, columns, beams and other structural systems | Yes for structural building work on Class 2 |
| Building enclosure | Roof systems; above-grade and below-grade walls including windows and doors that separate interior from exterior | Yes where enclosure work is involved |
| Mechanical, plumbing and electrical services required to achieve BCA compliance | BCA-required ventilation, smoke management interfaces, essential services wiring, hydraulic systems for BCA compliance | Yes for the BCA-compliance aspects of those services |
| Aspects of vertical transportation required for BCA compliance | Lifts and related BCA compliance aspects (where prescribed) | Yes for relevant VT work — use an authorised registration class |
| Performance solutions (any discipline) | Alternative solutions to DTS for fire, structure, energy, access, acoustics, etc. | Yes — performance solution designs are regulated designs under s 5 |
The Act also allows regulations to prescribe additional building elements or exclude things from being building elements. Always check the in-force Regulation on legislation.nsw.gov.au before treating a package as “out of scope”.
For enclosure / facade interfaces and structural packages, treat coordination as mandatory: enclosure details, waterproofing terminations and fire separations commonly intersect. Siloed drawings without integration are a common cause of late Portal rework.
When must Design Compliance Declarations be provided?
Under section 9 of the DBP Act, a registered design practitioner must provide a Design Compliance Declaration when they provide a regulated design that is in a form suitable for use in connection with building work — that is, construction-issued, not shop drawings or unresolved drafts.
Further DCDs are required when the practitioner varies a previously declared regulated design before the relevant building work starts (and in other circumstances prescribed by the regulations). Copies of DCDs must also go to any registered principal design practitioner appointed for the work.
NSW Fair Trading and nsw.gov.au guidance stress that designs lodged for construction must be construction issued regulated designs: they must contain the detail a building practitioner needs to carry out the work and be BCA-compliant. Drafts and incomplete packages do not satisfy the lodgement duty.
What is the lodgement sequence relative to construction?
Preparation of designs and DCDs is the RDP’s duty. Lodgement on the NSW Planning Portal is the registered building practitioner’s duty (unless delegated to an appropriate practitioner). Clause 16 of the DBP Regulation requires required documents to be provided to the Secretary in the approved way before building work commencing — and, where multiple construction certificates apply, before commencing the building work relating to each certificate.
- Confirm Class 2 / mixed-use scope — confirm the building (or part) is regulated and map exclusions.
- Inventory building elements and performance solutions — use the table above; assign registration classes.
- Prepare construction-issued regulated designs — integrate across disciplines as far as reasonably practicable.
- Issue Design Compliance Declarations — one DCD per regulated design on current Fair Trading forms.
- Principal compliance declaration (if PDP appointed) — the building practitioner must give any PDP 14 days’ written notice before building work starts so the principal declaration can be completed.
- Lodge on the NSW Planning Portal — building practitioner or nominated appropriate practitioner lodges: construction-issued regulated designs, each DCD, and principal compliance declaration if applicable.
- Only then start related building work — work must not start ahead of lodgement for the designs that relate to that work.
- Variations mid-build — varied building elements or performance solutions generally need updated regulated designs, new DCDs and re-lodgement before the varied work proceeds. See Class 2 design variations mid-build.
- Before occupation certificate — building practitioner lodges the building compliance declaration and any as-built / final regulated designs. Certifiers cannot issue an OC until required declarations are in place.
Documents can be uploaded progressively, but NSW Planning Portal guidance requires them to be lodged as a complete set before building work can commence for that package. Related reading: Class 2 compliance documentation on the NSW Planning Portal.
How should RDPs sequence declarations with building practitioners?
- Hold points in appointments: Make “DCD issued + Portal lodged” a contractual hold point equal to CC conditions — not a paperwork afterthought.
- Appropriate practitioner: A registered design practitioner or PDP on the same project may lodge designs and DCDs for the building practitioner. They cannot make the building compliance declaration.
- One building practitioner: NSW guidance states there is only ever one building practitioner for a project. Confirm who holds that role early.
- Certifier gate: Under the DBP Regulation, certifiers must obtain design compliance declarations and the related regulated designs before issuing a CC or CDC for Class 2, 3 or 9c work. Incomplete RDP packages delay certificates as well as site start.
- Approval pathway context: DA vs CDC does not remove DBP regulated-design duties for Class 2 building work. See Class 2 DA vs CDC pathways.
What exclusions and traps should inventory teams watch?
The DBP Regulation excludes certain work from being “building work” for scheme purposes (for example some exempt development other than waterproofing, and specified fire-system maintenance that is not a load-bearing stability component). Exclusions are narrow and fact-specific — do not assume a Class 2 apartment tower enjoys Class 3 low-risk exemptions published for hotels/motels without strata/serviced-apartment parts.
Common programme traps:
- Treating enclosure and waterproofing as “builder detail” after structure starts
- Leaving performance solutions undeclared until mid-construction
- Uploading drafts to the Portal and assuming that equals lodgement of construction-issued designs
- Starting trade packages before the related DCDs are lodged
- Ignoring vertical transportation and BCA-required services packages until late tender
For a plain-English Class 2 definition (BCA vs Class 1 / 3), see What is a Class 2 building?.
How can giantA help with Class 2 regulated designs and DCDs?
giantA Pty Ltd is a NSW Registered Design Practitioner practice for Class 2 work. We prepare and coordinate regulated design packages, Design Compliance Declarations and Planning Portal-ready documentation for apartment and mixed-use projects — helping developers and builders inventory building elements early and sequence declarations with construction. Contact giantA for Class 2 RDP / regulated design support tailored to your site. We do not publish fixed fees here; scope and program drive each fee proposal.
FAQ: Class 2 regulated designs and Design Compliance Declarations
What is the difference between a regulated design and a Design Compliance Declaration?
A regulated design is the design document (or performance solution report) for a building element or performance solution. A Design Compliance Declaration is the registered design practitioner’s declaration that accompanies that design when it is construction-ready.
Do all Class 2 drawings need a DCD?
No. The duty attaches to regulated designs for building elements and performance solutions (and other prescribed designs), not every sketch or non-building-element drawing. If work involves a listed building element, plan for a regulated design and DCD.
Who lodges DCDs 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). RDPs prepare and provide DCDs; lodgement is a builder-side obligation unless delegated.
Can building work start before all DCDs are lodged?
Building work relating to particular designs must not start before those construction-issued regulated designs and DCDs are lodged. Staged CCs require the required documents for the work relating to each certificate before that work starts.
Are performance solutions always regulated designs?
Yes under section 5 of the DBP Act: a design prepared for a performance solution for building work is a regulated design. Expect a DCD (and integration with other designs) before related work starts.
Do Class 2 renovations and remedial works need regulated designs?
Where the work is regulated building work involving a building element or performance solution on new or existing Class 2 buildings, yes — subject to the Regulation’s exclusions. Waterproofing and fire systems are frequent triggers on remedial jobs.
What must be lodged before an occupation certificate?
NSW guidance requires the building compliance declaration and any as-built / final regulated designs to be lodged on the Planning Portal before the OC application. Certifiers cannot issue an OC until required compliance declarations for the building work are lodged.
Where should I confirm the current building-element list and forms?
Use the in-force DBP Act (especially sections 5, 6 and 9) and Design and Building Practitioners Regulation 2021 on legislation.nsw.gov.au; design and building practitioner obligation pages on nsw.gov.au; Fair Trading declaration forms; and NSW Planning Portal developer/practitioner resources.
Sources: Design and Building Practitioners Act 2020 (NSW) ss 5, 6, 8, 9; Design and Building Practitioners Regulation 2021 (incl. cl 16 lodgement before building work); NSW Government — Design practitioner obligations; Building practitioner obligations; Certifier obligations for regulated buildings; NSW Planning Portal — developer and practitioner resources; National Construction Code / Building Code of Australia.