Design and Building Practitioners Act (NSW)

TL;DR

The Design and Building Practitioners Act 2020 (NSW) is the most substantial reform to NSW residential construction since the Home Building Act 1989. It introduces mandatory registration for design and building practitioners, regulated design lodgement on the NSW Planning Portal, compliance declarations signed by practitioners, and a statutory duty of care to all subsequent owners. Scope is currently Class 2, 3, and 9c buildings (multi-residential, residential care, day-care). From 1 July 2026, professional indemnity insurance becomes mandatory for registered building practitioners. Class 1a builders are not directly captured today, but the regulatory direction of travel is clear.

Background

The DBP Act emerged from the post-Opal Tower / Mascot Towers crisis of confidence in NSW Class 2 (apartment) construction. The Shergold-Weir review found systemic failures: unregistered designers, undocumented design changes, no clear line of responsibility, no insurance backing. The DBP Act addresses each.

Scope (current)

The Act currently applies to:

Class	Type	DBP Act applies?
Class 2	Apartments / multi-unit residential	Yes
Class 3	Residential care, motels, boarding	Yes
Class 9c	Aged care facilities	Yes
Class 1a	Single dwellings, duplexes	NOT yet (but signalled future expansion)
Class 4	Caretakers in commercial	Some elements
Class 5-9 (other)	Commercial / industrial	Not currently

The Class 1a residential builder is not directly captured today, but the regulatory direction is clear: expansion to other classes is on the policy table.

Key obligations

Registration

Practitioner	Registration required
Registered Design Practitioner (RDP)	Architects, engineers, others producing regulated designs
Registered Building Practitioner (RBP)	Builders, project managers on regulated work
Registered Professional Engineer (RPEng)	Engineers per separate framework

Registration is via NSW Fair Trading. Categories of registration include:

Building work: principal contractor / nominated building practitioner.
Design work: architectural, structural, fire safety, mechanical, electrical, hydraulic, geotechnical, building services.

Each registration class has competence and insurance requirements.

Regulated designs

A regulated design is a design document for a building element on a Class 2/3/9c building. Regulated designs include:

Architectural plans.
Structural engineering.
Fire safety design.
Mechanical and electrical services.
Geotechnical reports.
Hydraulic design.

Each regulated design must:

Be prepared or supervised by a registered design practitioner.
Be lodged on the NSW Planning Portal before the Construction Certificate.
Be accompanied by a design compliance declaration signed by the RDP.
Include any changes or variations as amended regulated designs with their own compliance declarations.

Compliance declarations

At key points, registered practitioners must sign declarations:

Declaration	Who signs	When
Design compliance declaration	RDP	At design lodgement
Building compliance declaration	RBP	At Occupation Certificate stage
Variation declarations	RDP / RBP	Each variation to regulated design

A false or misleading declaration is an offence under the Act.

Statutory duty of care

Section 37 imposes a statutory duty of care on every person who carries out construction work to:

Avoid economic loss caused by defects.
Defective work covered by the duty.
Owed to every subsequent owner of the land (not just the first purchaser).

This is the most far-reaching element of the Act. The duty applies retrospectively for 10 years (the standard limitation period for building defects).

Professional indemnity insurance (from 1 July 2026)

From 1 July 2026, registered building practitioners must hold professional indemnity insurance covering the duty of care. The insurance regime is still being finalised; expect:

Minimum sum insured to scale with project value.
Retroactive cover for past projects under the duty.
Premiums likely to be substantial (PI for building practitioners is a thin market).

Practitioners without PI from 1 July 2026 cannot operate on regulated work.

Enforcement

NSW Fair Trading administers the Act. Enforcement tools include:

Investigation powers: site inspections, document requests.
Show cause notices: practitioners explain why registration shouldn’t be suspended.
Suspension of registration: cannot operate while suspended.
Cancellation of registration: career-ending for registered practitioners.
Prosecution: fines for offences, including false declarations.
Stop work orders: under the EP&A Act, often invoked in parallel.

Common builder issues

Operating on Class 2 work without RBP registration: offence. Cannot legally do the work.
Engaging an unregistered designer: design lodgement fails; CC blocked.
Variations to regulated design not declared: defective compliance declaration; OC potentially refused.
No PI insurance after 1 July 2026: cannot operate on regulated work.
Duty of care exposure: defective work years later triggers Section 37 claim from a future owner.

For builders

Confirm your registration is current: NSW Fair Trading register lookup.
Confirm every design practitioner you engage is registered: don’t accept an unregistered structural engineer or hydraulic designer.
Budget for PI insurance from 1 July 2026: get quotes early; the market is constrained.
Maintain regulated design lodgement records: every Portal submission, every compliance declaration.
Document the supervision chain for site-amended designs: the RDP must sign the variation declaration.

Note: this article is general information, not legal advice. If you’re facing a DBP Act inquiry, engage a specialist construction lawyer.

References

DBP Act 2020 (NSW) full text: https://legislation.nsw.gov.au (verified 2026-05-15).
NSW Fair Trading DBP Act: https://www.fairtrading.nsw.gov.au (verified 2026-05-15).