Answer first: Yes, renovating an apartment in a NSW Class 2 strata building can trigger the Design and Building Practitioners Act. If the work involves waterproofing, structure, fire safety, the building enclosure or BCA-required services, a registered design practitioner must prepare regulated designs, lodged on the NSW Planning Portal before work starts — unless a Regulation exclusion applies.
By: giantA Pty Ltd · Updated 7 October 2026
Does the DBP Act apply when you renovate an existing apartment?
It can. NSW Government guidance on design practitioner obligations says that whenever there is building work on a regulated building involving a building element or a performance solution, a registered design practitioner must prepare regulated designs — and for Class 2 this applies to new and existing building work. Existing Class 3 and 9c buildings follow later, from 1 July 2028; Class 2 apartments are already covered.
Under the scheme, “building work” includes making alterations or additions to an existing building and the repair, renovation or protective treatment of a building. A “building element” means any of:
- fire safety systems (including passive fire)
- waterproofing
- building structure
- building enclosure
- building services required by the Building Code of Australia (BCA)
- the aspects of a vertical transportation product required for BCA compliance.
The rules also reach mixed-use buildings: regulated designs are required for all parts of a building that has a Class 2 part, such as apartments above offices or a car park. The NSW Planning Portal’s remediation works page adds that the DBP legislation covers building work on a Class 2 building, including rectification work whether building approval was required or not, and that designs must be lodged before work starts even where the work is not done under a construction certificate (CC) or complying development certificate (CDC).
For a broader overview of the elements themselves, see our guide to Class 2 regulated designs and building elements.
Which renovation work is excluded from the DBP scheme?
Clause 13 of the Design and Building Practitioners Regulation 2021 excludes certain work from being “building work”. If an exclusion applies, regulated designs and declarations are not required for that work. The exclusions most relevant to apartment owners, as summarised by NSW Government, include work that is:
- excluded from residential building work under the Home Building Act 1989 because the reasonable market cost of labour and materials does not exceed $5,000 — other than specialist work such as electrical wiring, plumbing, drainage, gas fitting, and air conditioning and refrigeration work (except plug-in appliances)
- carried out as exempt development under an environmental planning instrument, other than waterproofing
- waterproofing within a single dwelling carried out as a result of alterations to a bathroom, kitchen, laundry or toilet, where the alterations are exempt development (see below)
- maintenance of a component of a building, including a fire safety system, except a load-bearing component essential to the stability of the building
- maintenance of a component of a mechanical, plumbing or electrical services system
- the installation of a roofed structure over a balcony, deck, patio or terrace, unless it is above the existing topmost roof of the building.
Two traps catch owners: the $5,000 exclusion does not cover specialist trades such as plumbing and electrical work, and “exempt development” is a defined planning status, not a description of a small job.
When is bathroom or kitchen waterproofing excluded?
Waterproofing is the element most apartment renovations touch, and its exclusion is narrow. NSW Government’s remedial building work guidance says waterproofing is only excluded if it meets each of these conditions:
- it is carried out as a result of alterations to a bathroom, kitchen, laundry or toilet; and
- the work, including the agreement to carry out the work, relates only to a single dwelling; and
- it is exempt development.
NSW Government defines a single dwelling here as a single unit or townhouse. In practice that means:
- A like-for-like bathroom refresh in one apartment, carried out as exempt development, can fall within the exclusion.
- Balcony, terrace or roof waterproofing is not a bathroom, kitchen, laundry or toilet alteration, so the waterproofing exclusion does not apply — regulated designs are generally needed unless another clause 13 exclusion applies.
- One contract covering bathrooms in several units (for example, an owners corporation programme) does not relate only to a single dwelling, so the exclusion does not apply.
- A bathroom alteration that is not exempt development — because it needs a CDC or development consent — falls outside the exclusion.
Our earlier guide covers waterproofing in Class 2 buildings in more technical depth.
How do you know if the renovation is exempt development?
Exempt development is set by the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 (Codes SEPP). The Department of Planning’s fact sheet on remedial building work and the Codes SEPP explains that section 2.51 (minor building alterations, internal) sets a definitive list of repair, replacement and renovation works that can be minor internal alterations. To be exempt, works must also meet the general requirements in clause 1.16, including that the work:
- meets relevant fire safety requirements;
- meets the relevant deemed-to-satisfy provisions of the BCA or, where there are none, is structurally adequate; and
- does not cause an existing building to contravene the BCA.
The fact sheet adds that minor alterations are considered exempt where they do not permanently alter load-bearing capacity, keep the original design intent (“like-for-like”) and pose minimal impact. Otherwise the works may be complying development or need a development application — and even exempt work can still attract the DBP Act for elements such as waterproofing.
Moving walls, enlarging openings or altering fire-rated ceilings usually goes beyond like-for-like, so confirm the pathway early. Our guide to exempt development vs CDC vs DA explains the three routes.
Which common apartment renovations usually need regulated designs?
This is the first-pass screen we use when scoping strata apartment renovations — not a substitute for checking the building, by-laws and current law.
| Renovation item | Building element it may involve | Typical DBP outcome | Strata category (NSW guidance) |
|---|---|---|---|
| Interior painting, carpet, built-in wardrobes | Usually none | Usually outside the scheme | Cosmetic — no approval |
| New kitchen cupboards and benchtops, no services relocated | Usually none | Often outside the scheme; check any plumbing or electrical changes | Minor renovation |
| Bathroom renovation with new membrane in one apartment | Waterproofing | Excluded only if all three clause 13 conditions are met; otherwise regulated designs | Major renovation |
| Balcony retiling or re-membraning | Waterproofing, possibly enclosure | Regulated designs generally needed (the bathroom/kitchen/laundry/toilet exclusion does not apply) | Usually major; balconies are often common property |
| Removing or moving an internal wall | Structure if load-bearing; fire safety if fire-rated | Regulated designs likely if structure or fire separation is affected | Major renovation if structural; 14 days’ notice |
| Hard flooring replacing carpet | Usually none | Usually outside the scheme | Minor renovation — acoustic certificate expected |
| New or relocated plumbing, exhaust or ceiling penetrations | BCA-required services; passive fire | Assess case by case; specialist work is not covered by the $5,000 exclusion | Major renovation if waterproofing or ceiling changes |
| Replacing windows or doors to the façade | Building enclosure | Depends on whether the work is exempt development; assess before ordering | Minor renovation for double or triple glazing; check by-laws |
What approvals does the owners corporation need to give?
DBP compliance sits alongside, not instead of, strata approval. NSW Fair Trading’s strata renovation rules set out three types of renovation:
- Cosmetic work — no approval needed, provided it does not affect the structure or outside of the lot and does not require waterproofing. Examples include interior painting, filling minor cracks, laying carpet and installing built-in wardrobes.
- Minor renovations — approval needed. Examples include kitchen renovations, changes to internal walls, recessed light fittings and hard flooring. You must show plans with dates and times, the qualifications and details of the tradespeople, and, for flooring, an acoustic certificate. A strata committee can decide if a by-law allows it; a refusal must give written reasons within three months, or the application is taken to be approved.
- Major renovations — only the owners corporation can approve, by special resolution at a general meeting. These include changes to structure or the outside of the lot, changes that require waterproofing, ceiling changes, and work needing another approval such as council approval. Bathroom renovations and moving a structural internal wall are given as examples. For structural changes you must give the owners corporation 14 days’ written notice before work starts.
Work affecting common property may also need a by-law change, and owners affected by changes to common property must agree in writing — see NSW Fair Trading on strata by-laws. NSW Fair Trading’s renovation page also flags that strata renovations over $5,000 need regulated designs by a registered design practitioner and oversight by a registered building practitioner — read that alongside the clause 13 exclusions above.
Who does what on a Class 2 apartment renovation?
- Lot owner and owners corporation: the owner scopes the work and seeks approval; the owners corporation (or committee, where a by-law allows) decides it under the by-laws.
- Registered design practitioner (RDP): prepares construction-issued regulated designs and makes a design compliance declaration for each regulated design, within their class of registration. For waterproofing, NSW Government says architectural, structural or civil engineering design practitioners with relevant experience are authorised (façade practitioners for external façade waterproofing). Structural changes typically need a structural engineering design practitioner.
- Registered building practitioner: the one builder (or principal contractor) who does or oversees the work. For Class 2 they must hold an endorsed contractor licence for general building work. They are responsible for lodging regulated designs on the Planning Portal before work starts; a registered design practitioner working on the project can lodge as the “appropriate practitioner”.
- Certifier (if a CC or CDC is needed): cannot issue the certificate without the declared designs they require.
You can check practitioner registration on the NSW Government DBP register search. For how these roles interact on larger jobs, see RDP, building practitioner and PDP roles and RDP vs architect.
What is the step-by-step process for a compliant apartment renovation?
- Scope and measure. Record existing layout, wet areas, walls and services; gather the strata plan and by-laws.
- Classify the strata category. Cosmetic, minor or major, and whether common property is affected.
- Confirm the planning pathway. Exempt development, CDC or DA (with a CC to follow).
- Run the DBP screen. Does the work involve a building element or performance solution? Does a clause 13 exclusion genuinely apply?
- Apply for strata approval with drawings, trade details, an acoustic certificate if relevant, and the DBP position.
- Prepare regulated designs and declarations. Each regulated design needs its own design compliance declaration and the mandatory standard title block.
- Obtain any CC or CDC. The certifier will require the declared designs first. See Class 2 construction certificates.
- Lodge before work starts. The building practitioner (or appropriate practitioner) lodges the construction-issued regulated designs and declarations on the NSW Planning Portal.
- Control variations. If a building element changes on site, a varied design and declaration must be lodged within one day of the variation; work may need to pause. See Class 2 design variations mid-build.
- Close out. Where an occupation certificate is required, the building compliance declaration and any as-built designs must be lodged before the OC application. See Class 2 occupation certificates.
What mistakes do we see on strata apartment renovations?
- Assuming “small job” means “exempt”, and “exempt” means no DBP obligations.
- Treating balcony re-tiling as a cosmetic job, when it involves waterproofing and often common property.
- Removing a wall before confirming whether it is load-bearing or fire-rated.
- Engaging a builder who is licensed but not registered as a building practitioner for Class 2 work.
- Starting work after strata approval but before regulated designs are lodged on the Planning Portal.
Strata guidance warns owners may have to pay to restore the property after unapproved work, and Building Commission NSW audits regulated work. If works were already done without approval, see our guide to building information certificates.
Checklist before you sign a renovation contract
- Strata by-laws, strata plan and lot/common property boundaries checked
- Strata category confirmed (cosmetic, minor or major) and meeting date known
- Planning pathway confirmed: exempt development, CDC or DA
- DBP screen recorded: building elements involved and any clause 13 exclusion relied on
- Registered design practitioner engaged in the right class(es)
- Builder registered as a building practitioner for Class 2 (DBP register checked)
- Regulated designs, declarations and standard title block planned
- Planning Portal lodgement and variation process agreed in writing
Frequently asked questions
Do I need a registered design practitioner to renovate my apartment bathroom?
Often, yes. The waterproofing exclusion only applies if the alterations are exempt development, relate to a bathroom, kitchen, laundry or toilet, and relate only to a single dwelling. If any condition is not met, regulated designs by a registered design practitioner are required unless another clause 13 exclusion applies.
Is a balcony waterproofing job in my apartment excluded?
Not under the waterproofing exclusion. Balcony waterproofing is not an alteration to a bathroom, kitchen, laundry or toilet, so the clause 13 waterproofing exclusion does not apply. Balconies are also often common property, so owners corporation involvement is likely.
Does the DBP Act apply if no council approval or certificate is needed?
It can. The NSW Planning Portal says designs must be lodged before work starts even where the work is not done under a CC or CDC — unless a clause 13 exclusion applies.
Can my builder lodge the designs on the Planning Portal?
Yes — the registered building practitioner is responsible for lodgement. A registered design practitioner on the project can lodge as the appropriate practitioner, but only the building practitioner makes the building compliance declaration.
Is replacing carpet with timber or tiles a DBP matter?
Usually not, as flooring is not normally a listed building element. It is a minor renovation under strata rules, and NSW Fair Trading says you will need to show an acoustic certificate.
What if the job costs less than $5,000?
Work under the Home Building Act $5,000 threshold can be excluded, but specialist work such as plumbing, electrical, drainage and gas fitting is not covered by that exclusion.
Does this apply to Class 3 or 9c buildings too?
Not yet for renovations — NSW Government says renovation work on existing Class 3 and 9c buildings is covered from 1 July 2028. Existing Class 2 buildings are already covered.
How giantA can help
We help apartment owners, owners corporations and builders across Greater Sydney screen renovation scopes against the DBP Act and strata rules, and coordinate drawings, regulated designs and declarations. See our Class 2 building design service, design review, services and architectural services, read our Class 2 remedial building work guide for owners corporation projects, or ask giantA via Help.
Preferred sources (verify current versions)
- NSW Government — Design practitioner obligations when working on regulated buildings
- NSW Government — Remedial building work in regulated buildings
- NSW Government — Building classes and roles under the DBP scheme
- NSW Government — Certifier obligations when working on regulated buildings
- NSW Fair Trading — Strata renovation rules
- NSW Fair Trading — Strata by-laws
- NSW Planning Portal — Remediation works (DBP lodgement)
- NSW Department of Planning — Remedial building work and the Codes SEPP fact sheet
- Design and Building Practitioners Regulation 2021
- Design and Building Practitioners Act 2020
- NSW Government — DBP practitioner register search