Building a new home? Get your plumbing quoted stage by stage, from slab to fit-off.

How Much Does New Build Plumbing Cost in Canberra?

Published: April 2026 | By Jack Macfadyen, Licensed Plumber

Plumbing a standard 3 to 4 bedroom home in Canberra usually lands between $15,000 and $35,000, going by estimates from the Housing Industry Association (HIA) and Master Builders ACT. Where you land in that range comes down to how many bathrooms you have, what the kitchen is doing, which hot water system you pick, and whether there is gas fitting in the job.

How Is New Build Plumbing Priced by Stage?

The work is quoted and invoiced in three stages, which is why the quote is broken up the way it is.

Stage 1: Slab and Rough-In ($5,000 to $12,000)

This is the one you cannot afford to get wrong. Before the slab is poured, the plumber lays all the underground drainage, the sewer connection and the water supply pipes. That means setting the waste outlets for every toilet, shower, basin and the kitchen sink, and running the main supply line from the meter into the house.

Once the concrete goes down, those pipes are under it. Fixing a mistake at that point means cutting the slab, so the money you pay here is buying accuracy. What it costs depends on how many wet areas the house has and how far the sewer main is from the building.

Stage 2: Top-Out ($4,000 to $10,000)

With the frame up and the walls still open, the plumber runs the supply and waste pipes through the wall and ceiling spaces: hot and cold to every tap, shower, basin and appliance, plus the gas lines if you are having gas. The vent pipes go in at this stage too, so the drainage can breathe and the traps do not siphon out.

Top-out is where the design of the house shows up in the price. A single-storey place with one bathroom and the laundry backing onto the kitchen wall is cheap to run. A two-storey with bathrooms on both levels and the kitchen at the far end of the house is not.

Stage 3: Fit-Off ($4,000 to $10,000)

The last stage, where everything visible goes on: toilets, basins, taps, showers, baths, the dishwasher connection and the hot water system. The plumber then tests the lot for leaks and checks it all works before handover.

Your fixtures drive this number more than anything else. A builder-grade tap set costs a fraction of an architectural range. If you are supplying your own, show the plumber exactly what you have bought before they quote, because some of it takes twice as long to install.

How Much Does Each Additional Bathroom Add?

Every extra bathroom adds roughly $3,000 to $6,000, according to Hipages, which covers the pipework, the drainage and the fixtures. An ensuite with a shower, toilet and one basin sits at the bottom of that. A family bathroom with a bath, a shower, a double vanity and a toilet sits at the top.

Where you put it matters as much as how many you have. Stack a bathroom directly above another one in a two-storey and they share pipe runs, which saves you money. Put one on the far side of the house from every other wet area and you pay for the extra pipe and the extra labour to run it.

What Do Hot Water Systems Cost in a New Build?

Hot water is one of the bigger single line items. Your options:

• Electric storage, 250 to 315 litre, $800 to $2,500 installed. Cheapest to buy and dearest to run.
• Gas storage, 135 to 170 litre, $1,400 to $3,500 installed. Cheaper to run than electric, but you need gas connected.
• Gas continuous flow, $2,000 to $3,500 installed. Heats as it goes, so nobody gets a cold shower, and the unit takes up very little room.
• Heat pump, $2,500 to $5,500 installed. More upfront, much less to run, and it qualifies for the ACT rebate if you hold one of the concession cards.
• Solar with electric boost, $3,000 to $7,000 installed. The cheapest to run and the dearest to put in.

On a new build in most Canberra zones the two gas options are not available, because new homes can no longer get a gas network connection. Our explainer on the ACT rules on new gas connections covers which blocks are caught. There is a fuller breakdown of replacement pricing in our hot water system cost guide, and more detail on our hot water systems page.

How Much Does a Gas Connection Add to the Cost?

Read this part only if a new gas connection is still available on your block. Since December 2023 new homes in the residential, commercial and community facility zones cannot get one, so for most Canberra builds this line item is gone and the house is designed all electric instead. The ACT gas connection rules set out which blocks are still eligible.

Where gas is available and the house has gas appliances in it, a cooktop, hot water or heating, you need a connection from the street plus the internal gas pipework. The Evoenergy connection fee in the ACT depends mainly on how far your property sits from the gas main, and it usually falls between $1,500 and $4,000.

The internal gas fitting for a standard home with a gas cooktop, gas hot water and gas heating adds another $2,000 to $5,000, depending on how many gas points there are and how awkward the pipe runs get. A licensed gas fitter has to do the work, and they issue a compliance certificate when it is finished.

What Factors Increase New Build Plumbing Costs?

A few things about the design or the site will push you past the standard range:

• Split-level and multi-storey designs. Longer and more awkward pipe runs, sometimes a pump, and harder access to work in.
• Difficult sites. Poor access, a steep block, or a long way back to the sewer and water mains. All of it costs more to connect.
• Complicated kitchens. An island bench with a sink in it needs its own under-slab drainage. Pot fillers, boiling water taps and second sinks all add to the fit-off.
• Premium fixtures. High-end tapware, frameless screens with their own drain requirements and freestanding baths all take longer to install than the standard gear.
• Hydronic heating. Underfloor hydronic means a lot more pipe, laid to a plan, plus the boiler. It lifts the plumbing cost substantially.
• A rainwater tank plumbed into the house. Running it to the toilets, the laundry and the outdoor taps means extra pipework and a pump.

Should You Use the Builder's Plumber or Choose Your Own?

With a volume builder the plumbing sits inside the contract and their nominated plumber does it. You generally do not get a say. As an owner-builder you pick your own licensed plumber and you can shop the price.

Picking your own means you deal with the person doing the work, you get a properly itemised quote, and you have more say over fixtures and how things are done. The catch is that their schedule is now your problem to fit around the other trades.

If you are owner-building, get three quotes and check every one is priced on the same scope. Two quotes for different work tell you nothing. Our new build plumbing service covers all three stages, slab to fit-off.

What Compliance and Certification Is Required in the ACT?

Plumbing in a new ACT build has to comply with the National Construction Code and with AS/NZS 3500, the plumbing and drainage standard. The plumber needs a current ACT plumbing licence, and a separate gas fitting licence for any gas work.

The work gets inspected and signed off at each stage before the build moves on. At the end you get a compliance certificate covering the plumbing and gas work. Keep it. You need it for your building approval, and you will want it on file if you ever make an insurance claim.

How Do You Get an Accurate Quote for New Build Plumbing?

Give the plumber your architectural plans, the engineering drawings and a fixtures schedule listing every tap, toilet, basin and appliance you want in. The more of that you hand over at the start, the closer the quote will be to the final invoice.

Do not accept a price based on someone walking the site and describing the house. Quoting off the plans is the only way the number reflects the work that is actually in front of you.