Adding Electric Floor Heating to Your Renovation: What You Need to Know

If you're renovating your home — whether it's a bathroom refresh, a kitchen overhaul, or a full open-plan transformation — there's one upgrade that consistently delivers more comfort per dollar than almost anything else you can add: electric floor heating.

The best part? Adding floor heating during a renovation is far easier and more affordable than most people expect. If you're already pulling up tiles or pouring new screed, the heating element can go in at the same time with minimal extra cost or disruption.

Here's what you need to know before your renovation starts.

Why Renovations Are the Perfect Time to Add Floor Heating

The biggest cost in any floor heating installation isn't the heating element itself — it's the floor preparation. Removing existing tiles, preparing the substrate, and laying new flooring are all things that happen during a renovation anyway. Adding a heating mat or cable before the new tiles go down is a relatively small addition to a job that's already underway.

This is why we always tell homeowners: if you're renovating and there's any chance you might want floor heating in the future, do it now. Retrofitting later means pulling up the floor you just paid for — which nobody wants to do.

Under-Tile Heating: The Renovation-Friendly Option

For most renovation projects, the ELEKTRA DM20 under-tile heating mat is the ideal solution. These mats are designed to be installed directly on top of the existing substrate, beneath tile adhesive and new tiles. They add less than 4mm to the floor height — which is critical in renovations where door clearances, step heights, and transitions to adjacent rooms are already fixed.

The DM20 operates at 200 watts per square metre and is installed at 100mm spacings. It heats up quickly — typically reaching comfortable temperature within 20 to 30 minutes — making it ideal for rooms that are used intermittently, like bathrooms and ensuites.

The mats come in a range of standard sizes to suit common room dimensions, and they can be positioned to avoid fixtures, vanities, and other permanent installations. Your electrician connects the mat to a thermostat (usually mounted on the wall at standard light-switch height), and the system is ready to use once the tiles have cured.

In-Slab Heating: For Larger Renovation Projects

If your renovation involves pouring a new concrete slab — for example, a ground-floor extension, a garage conversion, or a full slab replacement — then in-slab heating with the ELEKTRA VCD35 cable is the better option.

The VCD35 is a twin-conductor heating cable installed at 200mm spacings on the reinforcement mesh, embedded directly in the concrete during the pour. It's designed for continuous, whole-of-house heating where the thermal mass of the slab stores and radiates heat evenly throughout the day.

In-slab heating is particularly effective with polished concrete floors, which are increasingly popular in Australian renovations. The concrete acts as a thermal battery — the system heats the slab during off-peak electricity hours, and the slab radiates warmth throughout the day without the system needing to run continuously. This can significantly reduce running costs compared to conventional heating.

What About Existing Concrete Slabs?

One of the most common questions we get is whether you can add heating to an existing concrete slab without replacing it. The answer depends on the situation.

If you're tiling over an existing slab, the DM20 under-tile mat can be laid directly on top of the slab, beneath the new tiles. This works well for bathrooms, laundries, kitchens, and other tiled areas. The mat sits in the tile adhesive layer, so the floor height increase is minimal.

If you want whole-of-house heating through an existing slab, that's more complex. In-slab heating needs to be embedded during the pour — it can't be added to an existing slab without cutting or overlaying. In these cases, we'd typically recommend under-tile mats in the areas where you're retiling, and consider other heating solutions for carpeted or timber-floored areas.

Planning Your Renovation Floor Heating

Getting floor heating right in a renovation comes down to planning. Here are the key things to discuss with your builder and electrician before work begins.

Electrical supply: Floor heating requires a dedicated circuit from your switchboard. For a single bathroom, this is a straightforward addition. For whole-of-house heating across multiple zones, you'll need to confirm your switchboard has capacity — your electrician can advise.

Thermostat placement: Each heated zone needs a thermostat. Plan the wall locations early so the electrician can run conduit before the walls are lined or tiled. Most homeowners place the thermostat just inside the room entrance at light-switch height.

Floor preparation: The substrate needs to be clean, flat, and free of sharp debris before the mat is laid. If your renovation includes levelling compound or waterproofing (as in bathrooms), the heating mat goes on top of the waterproofing membrane, beneath the tile adhesive.

Insulation: For ground-floor slabs, adding insulation beneath the heating element significantly improves efficiency. Even a thin layer of tile backer board or foam underlay can reduce heat loss downward and ensure more of the energy goes into warming your room rather than the ground.

Common Renovation Scenarios

Bathroom renovation: This is the single most popular application for renovation floor heating. A typical bathroom of 3 to 5 square metres can be heated with a single DM20 mat, controlled by a programmable thermostat. Total running cost is typically $10 to $20 per quarter — less than most people spend on their morning coffee.

Kitchen renovation: Open-plan kitchen and living areas are increasingly popular in Australian homes. Under-tile heating beneath a tiled kitchen floor keeps the space comfortable during winter without visible heaters or ductwork. For larger areas, multiple mats can be connected to a single thermostat.

Full home renovation: If you're doing a major renovation with new flooring throughout, a combination of under-tile mats (for tiled areas) and in-slab heating (for new slab areas) gives you whole-of-house comfort with zone-by-zone control.

Granny flat or studio conversion: Self-contained additions are perfect candidates for floor heating — they're typically built on new slabs, making in-slab heating easy to include during construction.

The 20-Year Warranty Advantage

Every ELEKTRA heating product — whether it's a DM20 mat or a VCD35 cable — carries a 20-year warranty. When you're investing in a renovation that you expect to enjoy for decades, knowing that the heating system buried beneath your new floor is warranted for 20 years provides genuine peace of mind.

Every cable and mat is individually tested at 2,500 VAC before leaving the factory. Not batch-tested — every single one. That's the level of quality assurance that matters when the product is going beneath a floor you don't plan to lift again.

Talk to the Renovation Heating Specialists

P.A.P. Heating Solutions has been helping Australian homeowners add floor heating to renovations since 1987. Whether you're tiling a single bathroom or transforming an entire home, we can help you choose the right system, calculate the correct sizing, and provide technical support through to commissioning.

We offer free consultation and system design for renovation projects anywhere in Australia. Call us early in your planning process — the earlier we're involved, the smoother the installation.

Phone: (02) 6242 9310
Email: info@papheatingsolutions.com.au
Office: 23 Winchcombe Court, Mitchell ACT

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