Renovating a strata apartment in NSW: what needs approval, and what owners underestimate

Renovating a house is a conversation between you, your builder and sometimes council. Renovating an apartment adds a fourth party: the owners corporation, which owns and maintains the common property around, above and below your lot. In most NSW strata schemes, the walls, floor slab, ceiling, and often the waterproofing membrane under your bathroom tiles are common property, not yours. That is why the law treats apartment renovations differently, and why the approvals matter even when the work looks like it is "just inside my unit".

This article explains how the Strata Schemes Management Act 2015 sorts renovation work, what owners most often underestimate, and what a committee should ask for before it approves anything.

The three tiers of renovation work

The Act groups work by owners into three tiers. The NSW Government's strata renovation rules set them out in plain terms.

1. Cosmetic work (section 109): no approval needed. Work that does not affect the structure or the outside of the building and does not need waterproofing. Examples in the Act and the government guidance include painting, filling minor holes and cracks in internal walls, laying carpet, installing handrails, hooks and blinds, and installing or replacing built-in wardrobes. You do not need permission, but you are still responsible for any damage to common property, and by-laws about noise, working hours and use of the lift still apply.

2. Minor renovations (section 110): approval by ordinary resolution. The Act lists renovating a kitchen, changing recessed light fittings, installing or replacing wood or other hard floors, installing or replacing wiring, cabling or power points, and work involving reconfiguring walls, and your by-laws can add to that list. Before asking for approval, you must give the owners corporation written notice with details of the work and any plans, the duration and times, who is doing it and their qualifications, and how rubbish will be managed. Approval is by a resolution at a general meeting (more than 50% of votes cast in favour), not a special resolution. If the scheme has a by-law that delegates these decisions to the strata committee, the committee can approve instead. Since 1 July 2025, where a committee has that power, it must give written reasons for refusing within three months of receiving the request, or the application is taken to be approved, as set out in the government's guide to the strata law changes.

3. Major renovations (section 108): special resolution and usually a by-law. Anything that changes structure, involves waterproofing, alters the external appearance, or needs council approval. That includes most bathroom renovations, because the membrane is usually common property or bonded to it. A special resolution is passed if not more than 25% of the value of votes cast are against it. The resolution must state who is responsible for the ongoing maintenance of the changed common property, which in practice is often done through a by-law.

The point owners miss most often: a bathroom is almost never a "minor renovation". The moment the work touches the membrane, you are in the major tier.

What owners underestimate

Waterproofing belongs to the building

The membrane under your shower protects the apartment below, the slab, and the reinforcement inside it. If it fails, the leak becomes the building's problem and, often, a dispute about who pays. That is exactly why the Act puts waterproofing in the major tier, and why a committee will expect the method, the membrane system and the waterproofer's certificate. Our article on wet area waterproofing explains what AS 3740 requires and why.

Hard floors and noise

Swapping carpet for timber, tiles or hybrid flooring is one of the most common sources of strata disputes. Two rules matter:

• By-laws. Many schemes have a floor coverings by-law. The model by-laws for residential schemes in the Strata Schemes Management Regulation 2016 include one requiring floor space to be covered or treated enough to stop noise likely to disturb another lot (kitchens, laundries, toilets and bathrooms excluded). Your scheme's registered by-laws may be stricter and may name a specific acoustic rating.
• The nuisance rule. Section 153 of the Act says owners and occupiers must not use their lot in a way that causes a nuisance to other occupiers. Footfall noise through a hard floor can be a nuisance, regardless of what the floor cost.

For new apartment buildings, the NCC sets minimum sound insulation for floors between units in Volume One, Part F7: an airborne rating of at least Rw+Ctr 50 and an impact rating of no more than Ln,w 62. Those provisions are written for new building work. Whether they apply directly to your renovation depends on whether the work needs approval, but they are a sensible benchmark, and many schemes reference similar figures in their by-laws. The practical answer is the same either way: specify an acoustic underlay with a tested rating for the floor system you are installing, and have it on paper before the committee asks.

Structure, penetrations and fire separation

Apartment walls and floors do jobs you cannot see. Some walls are load-bearing. Floors and many walls between units are fire-rated, and so are the shafts that carry services. Cutting a new hole for a downlight, an exhaust duct, an air-conditioning line or a relocated drain can breach a fire-rated element or a membrane. Any penetration through a rated element has to be re-sealed with a tested fire-stopping system, and any structural change needs an engineer. This is why these items sit in the major tier.

Council, as well as strata

Strata approval is not planning approval. Some minor internal alterations can be exempt development under the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, subject to its conditions. Work outside those conditions, including many structural changes, may need complying development or development consent. Check with council or a certifier, and tell the committee what you found.

The building around the job

• Working hours are usually set by by-law, and sometimes by council conditions.
• Lift and common area protection, booking the lift, and removing waste without using the building's bins.
• Licensed trades and insurance. Plumbing, electrical and waterproofing must be done by licensed trades. Your builder should hold contractor's insurance, and home building compensation cover may be required depending on the contract value.
• Neighbours. A short note before demolition does more for a project than any by-law.

What a committee should ask for

A good application lets the committee approve with confidence and protects the owner as much as the building. We suggest committees ask for:

1. A written scope, stating which tier the owner believes the work falls in and why.
2. Drawings or a marked-up plan showing walls, wet areas, fixture locations and any penetrations.
3. The waterproofing method: membrane system, standard and edition (AS 3740:2021 for wet areas), who will install and inspect it, and a commitment to provide the compliance certificate and photographs.
4. Acoustic specification for any hard flooring, with the underlay's tested rating.
5. Licences and insurance for the builder and trades, with current certificates.
6. Engineering advice for any structural change, and details of fire-stopping for any penetration.
7. Working hours, lift protection and waste arrangements.
8. A draft by-law or resolution for major work, covering who maintains the changed common property and who pays if it fails.

Keep the records. The owners corporation must now keep a record of approved minor renovations for 10 years, and you should keep your own copies too, and if a defect appears later, the paperwork is what tells you who is responsible. Our post on strata defects reports covers what happens when things do go wrong.

How we approach apartment renovations

We start with the strata plan and the by-laws, not the tile selection. Before quoting, we work out which tier the work falls into and what the committee will need, and we prepare the scope, plans, waterproofing method, acoustic specification and insurances as a ready-to-table package. During the job, the membrane and any fire-stopping are inspected and photographed at hold points before they are covered, and the certificates go to both the owner and the owners corporation at handover. It is the same discipline we describe in why the NCC matters: the standard is the brief, and the record proves it was met.

If you are planning an apartment renovation, or you sit on a committee reviewing one, get in touch. We are happy to talk through what approval the work needs before anyone commits to a design.

Sources

• Strata Schemes Management Act 2015, NSW Legislation (sections 5, 108, 109, 110 and 153)
• Strata renovation rules, NSW Government
• Guide to strata law changes for strata committees and owners, NSW Government
• Strata Schemes Management Regulation 2016, NSW Legislation (model by-laws)
• NCC 2022 Volume One, Part F7 Sound transmission and insulation, Australian Building Codes Board
• State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, NSW Legislation

This article is general information, not legal advice. By-laws differ from scheme to scheme, and the approval your work needs depends on your strata plan, your registered by-laws, the work proposed and council requirements. Check your scheme's by-laws and get advice from your strata manager, a certifier or a strata lawyer where needed. Full website disclaimer