Best Underfloor Heating System for Renovations

A practical guide to choosing the right system for existing homes in Devon and Cornwall.

Underfloor heating is increasingly popular in renovation projects, but choosing the right system is more complicated than in new builds. The best option depends on your floor construction, how much disruption you can accept, and your budget.

Here’s a clear breakdown of the systems that work well in renovation projects.

Main Challenges in Renovations

Floor Height Build-Up

Adding underfloor heating can raise floor levels, which may affect doors, skirting boards, and transitions between rooms. Keeping the build-up as low as possible is often a priority.

Disruption

Some systems require lifting floorboards or removing existing flooring. If you're living in the property during the works, minimising disruption becomes very important.

Floor Construction

Many older properties have a mix of solid concrete floors on the ground floor and suspended timber floors upstairs. Each requires a different approach.

Heat Source

Underfloor heating performs best with lower water temperatures. If you're installing it alongside a heat pump, this becomes even more important.

Recommended Systems for Renovations

1. Overlay Systems (Most Popular Choice)

These systems are laid on top of an existing solid floor. They cause relatively little disruption and have a low build-up height.

Pros

  • • Low floor height increase
  • • Faster installation
  • • Less disruption
  • • Good performance with modern systems

Cons

  • • Higher cost per m² than screed
  • • Slightly less thermal mass

2. Between Joist Systems

Used in suspended timber floors where floorboards can be lifted. These systems sit between the joists and are a good option for period properties.

Pros

  • • Minimal floor height increase
  • • Good for timber floors
  • • Works well when properly insulated

Cons

  • • Performance depends heavily on insulation
  • • More labour intensive

3. Structural Board Systems

These combine structural support and underfloor heating. Useful when replacing floors during a renovation.

Pros

  • • Good structural performance
  • • Can replace existing floor structure
  • • Decent heat output

Cons

  • • Higher cost
  • • Performance varies between products

Our Recommendation

For most renovation projects in Devon and Cornwall, we generally recommend modern overlay systems on solid floors and between joist systems on suspended timber floors.

The right choice depends on your specific situation. Getting advice from someone experienced in both underfloor heating and renovation projects can help you avoid costly mistakes.

Planning underfloor heating as part of a renovation?

Use our Underfloor Heating Calculator to get recommendations based on your floor type and project.

Open the Underfloor Heating Calculator Try the Combined Estimator

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→ Underfloor Heating Costs in Devon & Cornwall 2026 → Underfloor Heating for Renovations → Overlay vs Screed Underfloor Heating Comparison → Heat Pump + Underfloor Heating: Is It Worth It?