Apartment Bathroom Renovation in Sydney: 2026 Strata, Costs and Practical Constraints Guide

If you’ve been searching apartment bathroom renovation Sydney, you’ve probably already run into the limits of generic renovation advice. Apartments aren’t houses. The plumbing rules are different, the strata committee has opinions, the building manager has a schedule, and the bathroom directly below yours belongs to someone who will not enjoy water cascading through their ceiling. This guide is for Sydney apartment owners planning a bathroom renovation in 2026.

At T3 Interior, we renovate apartment bathrooms across Sydney, from one-bedroom units in Surry Hills to penthouse ensuites in the Eastern Suburbs. Book a no-obligation site assessment if you want a working builder’s read on your specific apartment.

Why Apartment Bathroom Renovations Are Different

Five things change the moment you renovate a bathroom inside a strata building:

Common property vs lot property. The waterproofing, the floor slab, the walls between units, and most pipework are common property. You can’t legally alter them without strata approval, and in many buildings the strata committee is involved in the decision.
Hours of work. Most strata schemes restrict noisy work to weekdays, typically 8am to 4pm, no weekends or public holidays. That alone adds 30% to 50% to the build duration compared with a house.
Access constraints. Tradespeople need to use lifts (often a service lift only), park in visitor bays for limited hours, and book loading dock time slots. Larger items like a freestanding bath have to fit through the front door.
Plumbing stack realities. Apartment toilets and showers usually drain into a shared stack inside the wall. Moving the toilet two metres can require coring through the slab into the unit below, which is often impossible.
Waterproofing accountability. If your renovation leaks into the unit below, you (not the builder, not strata) carry the legal liability. That makes waterproofing the single most important spec in the entire job.

Strata Approval: What You Actually Need

Most NSW apartment buildings operate under the Strata Schemes Management Act. For a bathroom renovation, expect to go through one of three approval pathways:

Minor Renovation (Section 110)

Cosmetic work like replacing tapware, vanities, toilets (like-for-like, in the same position), and tiles without affecting waterproofing. Requires written notice to strata, typically approved by the secretary or strata manager. Lead time 1 to 3 weeks.

Cosmetic Work (Section 109)

Even more limited. Painting, replacing handles, minor non-structural work. Usually doesn’t require formal approval but check your building’s specific by-laws.

Major Renovation (Section 108)

Anything that affects waterproofing, common property, pipework, or the structural slab. This is most full bathroom renovations. Requires a special resolution at a general meeting (75% approval), and the owners corporation will usually require:

Detailed drawings and scope of works
Builder’s licence and insurance certificates
Hydraulic engineer’s report
Waterproofing specification (BCA-compliant, AS 3740 certified)
A by-law to record the renovation and assign ongoing maintenance to you (the lot owner) in perpetuity
Bond or security deposit ($1,000 to $10,000), refundable on satisfactory completion

Realistic timeline from first submission to formal approval: 6 to 14 weeks, longer if the strata committee meets quarterly or there are objections. Start the strata process before you finalise design, not after.

What an Apartment Bathroom Renovation Costs in Sydney (2026)

Realistic 2026 pricing for Sydney apartment bathrooms, excluding strata fees and bond:

Cosmetic refresh (vanity, tapware, tiles, no layout change): $18,000 to $30,000
Standard full renovation (new layout in same footprint, full waterproofing): $30,000 to $55,000
Premium renovation (custom joinery, stone, premium tapware, integrated lighting): $55,000 to $90,000
Ensuite + main bathroom combined project: add 60% to 80% to single-bathroom cost
Penthouse or premium apartment with high finishes: $90,000 to $150,000+ per bathroom

Apartment bathrooms cost 15% to 30% more than equivalent house bathrooms for the same finishes, because of strata fees, restricted work hours, access constraints, and the engineering needed for waterproofing without being able to drop the slab.

Plumbing Reality: What You Can and Can’t Move

This is where most apartment bathroom dreams meet reality. The shared plumbing stack determines almost everything.

Toilet: Generally cannot be moved more than 30 to 60cm from the existing position without major engineering. Some buildings absolutely prohibit it.
Shower: Can usually be moved within the bathroom footprint, but the floor needs to fall correctly to the waste, and the waste position is constrained by the slab.
Vanity: Most flexible. Can be repositioned anywhere within the wet area as long as supply and waste can reach.
Bath: Difficult to add to an apartment that didn’t have one (slab can’t usually be dropped). Sometimes possible with a freestanding bath on a raised platform.
Underfloor heating: Possible, electric only (hydronic requires slab work that’s rarely allowed). Adds about $80 to $150 per square metre.

Get a hydraulic engineer’s assessment before you commit to a design. It costs $1,200 to $3,500 and saves you from designing a bathroom your building physically can’t accommodate.

Waterproofing: The Spec That Actually Matters

Waterproofing failure is the most common, most expensive, and most legally fraught problem in apartment bathroom renovations. A proper Sydney apartment bathroom waterproofing job in 2026 includes:

Compliant membrane to AS 3740-2021 (latest standard)
Minimum 150mm membrane height around shower walls (more in shower-only enclosures)
Sealed penetrations at every pipe, drain, and fixture
Independent waterproofer (not the tiler) with current NSW licence
Pre-tile leak test (24-hour flood test) with documentation
Photographic record of every stage for insurance and strata records

Insist on a written waterproofing certificate signed by the licensed waterproofer at handover. Keep it forever. If you ever sell, the buyer’s conveyancer will ask for it.

Layout Ideas That Actually Work in Sydney Apartments

1) Wet Room Conversion

Removing the shower screen and tiling the entire bathroom as a single waterproofed zone. Makes small apartment bathrooms feel 30% larger, improves accessibility, and reduces cleaning. Requires a properly graded floor and high-spec waterproofing. Suits bathrooms under 4.5 square metres.

2) Vanity-Over-Toilet

A wall-hung vanity that cantilevers over a wall-hung toilet, used in tight 1-bedroom apartment bathrooms to maximise floor space and visual flow. Looks great in renderings; requires a builder who can detail the millwork properly.

3) Mirror Cabinet Behind the Vanity

Apartments rarely have linen cupboard space. A full-width mirrored cabinet above the vanity, with integrated LED, recovers 0.3 to 0.5 square metres of storage and doubles as the mirror.

4) Pony Wall Shower Divider

Half-height tiled wall instead of a glass screen for the shower. Creates separation without visually shrinking the room. Especially effective in long, narrow apartment bathrooms.

5) Niche Storage

Recessed wall niches in the shower and beside the vanity provide storage without taking floor space. Has to be planned before tiling and waterproofing, not after.

How Long Does an Apartment Bathroom Renovation Take?

Strata approval: 6 to 14 weeks
Design and engineering: 4 to 8 weeks (often runs parallel to strata)
Material procurement (especially stone and custom joinery): 4 to 8 weeks
On-site construction: 5 to 9 weeks (slower than a house because of weekday-only working hours)

Total project from first conversation to using your new bathroom: 5 to 8 months. Plan to use a different bathroom in the apartment, a friend’s place, or a short-term rental during the on-site phase.

Common Mistakes Sydney Apartment Owners Make

Designing the bathroom before talking to strata. Find out what your by-laws and committee will actually allow before paying for drawings.
Choosing a builder unfamiliar with strata buildings. Apartment renovations have a paperwork and access layer that catches out house-only builders.
Skipping the hydraulic engineer. Wishful thinking about moving the toilet 1.5 metres is the most expensive lesson in apartment renovation.
Cheap waterproofing. Save $1,500 on the membrane, spend $80,000 fixing the unit below five years later. Don’t.
Ignoring the bond. Strata bonds are real money. If the lift gets damaged or the corridor needs repainting, it comes out of your bond first.
Booking install during the lift maintenance window. Check the building’s scheduled maintenance and major works calendar before locking in construction dates.

How T3 Interior Handles Apartment Bathroom Renovations

Our process for apartment bathrooms:

On-site walkthrough including assessment of plumbing stack, slab structure, and access constraints
Strata consultation: we work with your strata manager or committee directly
Concept design constrained by what’s actually possible, not what looks good in a rendering
Hydraulic and waterproofing engineering documentation included in the package
Strata submission support (drawings, scope, by-law drafting, certificates)
Construction within strata work-hour rules, with daily site clean and protection of common areas
Pre-handover flood test and waterproofing certification

We’ve worked across older brick walk-ups, mid-tier strata towers, and newer high-rise apartments. Each has its own quirks, but the principles stay the same: respect the plumbing, over-spec the waterproofing, and document everything.

Ready to Talk About Your Apartment Bathroom?

If you’re at the point of planning an apartment bathroom renovation in Sydney, the cheapest move is a proper site walkthrough before you commit to drawings. Get in touch with T3 Interior to book a free no-obligation assessment.