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Sydney — Tier-1 Pillar

Sydney Bathroom Renovation — Waterproofing AS 3740, Strata Consent, Licensed Plumbing

Sydney bathroom renovation reality. AS 3740 waterproofing to the letter, licensed plumbing and Sydney Water Certificate of Compliance, strata Owners Corporation consent, BASIX water targets, asbestos survey pre-1990. A$22K-A$55K typical.

~2 min read·Updated 2026-04-23

Sydney bathrooms fail in two places: the waterproofing membrane and the strata consent. Both can be prevented. AS 3740-2021 is the binding standard for waterproofing of domestic wet areas, and compliance is demonstrated via a waterproofing certificate issued by a licensed waterproofer. Any licensed plumber doing supply, sanitary, or stormwater work must lodge a Sydney Water Certificate of Compliance on completion. On strata stock — 70% of Sydney residential — Owners Corporation consent under the Strata Schemes Management Act 2015 is typically required because bathroom waterproofing sits on the boundary between lot and common property, and a leak below affects a neighbour.

AskBaily routes your Sydney bathroom renovation to a NSW-licensed builder who carries waterproofing certification, plumbing certificates, and strata by-law experience in-house.

What a Sydney bathroom renovation involves

  • Waterproofing. AS 3740-2021 compliant membrane on floor, hobs, and walls to 1800 mm in shower zones. Waterproofing certificate retained with title.
  • Plumbing. Licensed plumber + Sydney Water Certificate of Compliance for any supply or sanitary work. Trade-waste approval for unusual fixtures (butler's sinks, steam rooms).
  • Electrical. Licensed electrician + CCEW. IPX4+ fittings within shower zone 1, RCD protection on every circuit.
  • Strata. SSMA 2015 Owners Corporation consent. Expect A$500-A$2,500 in manager and surveyor fees, plus 4-12 weeks to by-law registration.
  • BASIX. Water fixtures at 4-star WELS minimum (showerheads, taps, toilets). Hot-water system efficiency under the BASIX target.
  • Asbestos. Pre-1990 wall sheeting and floor vinyl often contain asbestos. Pre-works survey mandatory; SafeWork NSW licensed removalist over 10 sqm.

Frequently asked questions

Do I need council approval for a Sydney bathroom renovation? Usually no. A like-for-like bathroom refit on internal fabric is typically exempt development. Any change that affects external walls, fire separation, or heritage fabric pushes into CDC or DA. Strata consent is almost always required regardless.

What is the waterproofing certificate and why does my solicitor ask for it? AS 3740-2021 compliance is demonstrated via a licensed waterproofer's certificate, dated and referenced to the job. Buyers' solicitors request the certificate at conveyancing as evidence that the waterproofing was done by a certified tradesperson. A missing certificate discounts the property at sale.

How much does a Sydney bathroom renovation cost? A$22,000-A$32,000 for a mid-range strata bathroom refit. A$38,000-A$55,000 for a high-spec bathroom with stone, custom vanity, and frameless glass. A$70,000-A$150,000 for a master ensuite with steam shower, heated floors, and imported fixtures. Budget 6-10 weeks from strip-out to handover.

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