How to Renovate a Bathroom: Step-by-Step Guide

Description: A complete bathroom renovation walkthrough covering demolition through to finished fitout, providing practical visual guidance for each stage covered in this step-by-step renovation guide.
Video Credit: DIY & Crafts

Now, you can almost imagine entering your bathroom, but this time you're entering the room of your dreams, your new tile flooring under your feet, a gorgeous vanity taking centre stage, and your grout lines perfectly reflecting the ambient light. As you stand gazing at this idyllic bathroom, you can't help but wonder "That looks amazing but is it a pain in the backside to complete?"

So let's break it down, step by step.

Step 1: Plan Your Bathroom Renovation

A bathroom renovation project succeeds or fails on the degree of prep work that is done before starting. Before even breaking one of your bathroom's existing tiles, you'll want to take precise measures of your current bathroom: the width and length of your floor plan, the ceiling height, where windows and doors are, and most critically where your existing water supply and drain points are. This data allows you to decide which style of bathroom design you'll go with and what will work best in your space: whether a one-wall layout, which is perfect for small, confined bathrooms; an L-shape layout or fully wet rooms, both of which are perfect for more sizable bathrooms.

Next, you want to pull together a full bathroom renovation checklist to refer to during the entire process. Questions to include here would be: "where will your fixtures fit?", "where does your wet area fall?", "is your door swing clear of other bathroom fixtures?", "does your space have enough air circulation?", and "what does the room need regarding extra storage?". This checklist will become your bible as you undergo your bathroom renovation. You should also consider the necessary council permits and the areas that require a professional to handle. Plumbing, waterproofing, or electrical work, for example, all must be undertaken by a licensed tradesperson in almost all states and territories in Australia. Overlooking this step is a frequent cause of budget overruns later down the road.

Now that your plan has been confirmed and your bathroom renovation checklist is in order, you're ready to convert your plan into a budget — knowing your budget before the renovation begins will help you sidestep unexpected expenses while you renovate.

Three bathroom renovation tiers illustrated with costs from $10k to $30k-plus

Step 2: Set Your Budget and Understand Costs

Let's discuss bathroom renovation cost in practical terms. It will depend on the size and location of your home and the level of quality of the finishes that you've selected. In general, a small ensuite will cost between $10,000 and $25,000, a mid-size family bathroom will range closer to $15,000–$30,000, and a top-notch complete renovation will easily push well beyond that (HIA Bathroom Renovation Cost Guide 2025). Renovation costs for a project of this nature are generally higher in cities such as Sydney or Melbourne than in regional Australia.

You will also need to factor in costs for a variety of trades — a licensed plumber, a tiler, and an electrician, for instance. The waterproofing membrane and tiles are each calculated per square metre, and then you have the vanity, toilet suite, shower screen, and tapware to buy. Always include a contingency of 10–15 per cent. Unexpected problems may arise when demolition starts — asbestos removal, structural wall changes, or re-routing plumbing, among others — and this reserve amount can ensure that you will not be caught out.

Once your budget has been set and a contingency amount has been put aside, you are ready to start the work.

Person using chisel and hammer to remove grey mosaic wall tiles

Step 3: Demolition and Preparation

Following the bathroom renovation steps in the correct order is essential, and demolition is where that sequence begins. Demolition takes the bathroom back to a clean substrate ready for a solid frame. First, your licensed trades will isolate the water supply and electrical to the area — never skip this. Then they will strip out any old fittings, fixtures, and tiling, all the way back to the frame. This is where the hidden problems reveal themselves: any mould in your lining; any timbers rotting out in your subfloor; or — in homes built before 1990 — asbestos-containing materials that will need to be removed by licensed professionals and remediated before work can continue.

Trades must be engaged in a specific order. Demolition first, then frame repair, then rough-in plumbing, then rough-in electrical. If your substrate — cement sheet or villaboard — is not prepared correctly, there will be problems with the waterproofing membrane, which will lead to problems with the tiles. Demolition and preparation are not the glamorous part, yet it is in this stage that the foundation is laid. Once you have your bathroom demolished and your substrate prepared, it is time for the most technical stage: licensed trades carrying out the rough-in work, waterproofing to Australian Standards, and then tiling.

Hands repairing a bathtub faucet on a white tile wall with exposed pipe.

Step 4: Plumbing, Waterproofing, and Tiling

Your licensed plumber will rough-in all waste pipes, water supply piping, and position traps — 100–120 mm for S-traps and 185 mm for P-traps. Your licensed electrician will run conduit for your exhaust fan and all electrical fittings. This work must be completed by a licensed professional and, depending on state legislation, they may be required to issue compliance certificates. In most Australian states — check your state/territory requirements — this is not a DIY job, and the same principle applies to waterproofing.

When it comes to waterproofing, there is no argument: shower walls must be waterproofed to 1800 mm (AS 3740:2021) (NCC 2022, ABCB Housing Provisions, Part 10.2) above the floor substrate, and the entire floor is waterproofed. Your licensed waterproofer will apply waterproofing membrane coats and bond breaker at all internal corners. The membrane needs to fully cure for 24–72 hours before the tiling team can start work. Tiling over an un-waterproofed substrate is the number one cause of water penetration into walls and floors.

Select tiles with the correct AS 4586 slip-resistance rating — for a shower floor this must be at least P4 or P5. Large-format tiles such as 600×600 mm or 600×1200 mm create a sleek look, while smaller mosaic formats suit curves. Your tiler will advise on the laying sequence for your layout.

Worker installing a shower head in a marble tile bathroom with glass shower door.

Step 5: Shower Screen, Toilet, Tapware, Vanity and Basin

This is where the magic happens. Generally, the order of works goes shower screen, toilet, then tapware, vanity and basin. Shower screen glass is subject to the safety glazing requirements of AS/NZS 2208 and must be 6 mm or 10 mm thick tempered safety glass, measured and installed professionally. Your licensed plumber will install all tapware and basin connections — all plumbing fittings must carry WaterMark certification. Bathroom electrical installations — any hardwired LED mirror, heated towel rail (ThermoGroup is a specialist brand for these), exhaust fan, and other electrical fittings — must be installed by a licensed electrician in most Australian states and territories; check your state/territory requirements.

For vanity sizing, measure your space and select a standard cabinet width: 600 mm, 750 mm, 900 mm, or 1200 mm. Cabinet material options include PVC (inherently moisture resistant, lowest price point), moisture-resistant MDF (mid-price point), or plywood (higher price point and more durable — Aulic offers premium Australian-made plywood vanities). The vanity cabinet is just one component of your vanity unit; the basin or top is a separate sub-component and must be purchased and considered independently.

The good news is you don't have to blow a fortune on your vanity. There are plenty of well-designed affordable bathroom vanities that suit a tight budget, and when paired with quality WaterMark tapware, they produce a great-looking bathroom. A low cost bathroom vanity finished in PVC can still look excellent with the right basin and mixer. Even the cheapest vanity options can work well when accessorised thoughtfully. Understanding how to renovate a bathroom helps you manage your overall bathroom renovation cost and make the most of every dollar.

A full bathroom renovation from demolition through to practical completion generally takes four to six weeks, subject to scope and trade availability. Keep your bathroom renovation checklist active through every phase to stay on track with each trade.

References

HIA (Housing Industry Association) — Bathroom Renovation Cost Guide 2025

AS/NZS 3000:2018 Electrical Installations (Wiring Rules), Standards Australia

State plumbing licensing legislation (VBA Victoria; Fair Trading NSW; QBCC Queensland; Building Practitioners Board WA; CBOS Tasmania; ACTPLA ACT; Building & Energy SA; ABPB NT)

National Construction Code 2022, ABCB Housing Provisions, Part 10.2 Wet Areas

AS 3740:2021 Waterproofing of Domestic Wet Areas, Standards Australia

FAQs

How long does a typical bathroom renovation take from demolition to final fit-out?

For a standard mid-size bathroom, allow four to six weeks from the first day of demolition through to practical completion. The biggest time variables are waterproofing cure times, tile grout drying, and trade availability — trying to compress the schedule by overlapping wet trades is one of the most common causes of callbacks and defects.

Can I reuse existing plumbing positions to keep costs down?

Yes, and it is one of the smartest budget decisions you can make. Keeping waste and supply points in their original locations avoids costly re-routing through concrete slabs or timber frames, which can add thousands to your plumber's bill. If your layout allows it, design around what is already there before committing to a new floor plan.

What is the most common mistake homeowners make when selecting grout colour?

Choosing a grout colour in isolation rather than against the actual tile sample in your bathroom's lighting conditions. Grout can read dramatically warmer or cooler under artificial light than it did in a showroom, and once it is cured, changing it is a significant undertaking — always test a small section first.