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Retrofit Underfloor Heating for Existing London Homes

You don't need a new build for wet underfloor heating. Low-profile retrofit systems add just 15–25mm of floor height — practical in Victorian terraces, flats and period conversions.

How It Works

How does low-profile retrofit underfloor heating work?

Pre-routed low-profile boards go on top of your existing floor, the warm-water pipe is pressed into the channels, and your new floor finish goes straight over. No excavation, no new screed slab.

The build-up adds roughly 15–25mm — about the thickness of an engineered wood plank. Most rooms absorb that within the floor finish or a threshold strip; doors occasionally need a trim.

It behaves exactly like screeded UFH: water at 35–45°C circulates through each room's loop from a central manifold, with no radiators taking wall space.

Key fact: Low-profile retrofit wet UFH adds ~15–25mm of floor height and runs off your existing boiler or a heat pump — no major building work.

London Housing Stock

Can underfloor heating be retrofitted in a Victorian terrace or period flat?

In most cases, yes:

We never quote blind. The site survey tells us your floor construction, insulation and heat source — and we'll tell you straight if a room isn't a good candidate. Recent retrofit and screeded installs are on our work page.

Low-profile wet underfloor heating being installed across a bright room in an existing London home
A retrofit installation in progress — laid over the existing floor, room by room.
Step by Step

What is the retrofit installation process?

  1. Site survey. We measure each room, check floor build-up, door clearances, insulation and heat source. Free written quote within 24 hours.
  2. Design & zoning. Heat loss calculations per room, pipe spacing, loop layout and a manifold plan — each zone gets its own thermostat.
  3. Installation. Boards go down over the prepared floor, pipe into the routed channels, manifold mounted and connected to your heat source.
  4. Pressure test. Every loop is tested before anything is covered — proven leak-free while it's still accessible.
  5. Commissioning. We balance the manifold, set up the blending valve and thermostats, and hand over with a workmanship guarantee.
Pressure testing a retrofit wet underfloor heating system before the floor finish is laid in a London property
Every loop is pressure tested before the floor finish goes down — proven tight while it's still visible.

How long does a retrofit take?

Project Typical Timeline What Drives It
Single room A few days Floor prep, board laying, manifold tie-in
Several rooms / one floor Around 1 week Zoning, levelling compound drying where used
Whole house 1–3 weeks Floor area, number of zones, screed drying time where used

Typical timelines, confirmed in your free written quote. We sequence the work room by room so your home stays liveable.

Does retrofit UFH work with my existing boiler — or a heat pump?

Both. The manifold's blending valve tempers a standard combi or system boiler down to the 35–45°C the floor needs, and the UFH can run alongside any radiators you keep.

Planning an air source heat pump? Heat pumps are most efficient at exactly these low flow temperatures, and a floor we install today reconnects to one later without being lifted. Our London cost guide covers the numbers; our wet vs electric comparison explains why electric mats can't make the same switch.

Why London homeowners choose Meridian for retrofits

Levels, thresholds, suspended floors and period quirks all need judgement before the first board goes down. We bring over 5 years of UFH experience, Gas Safe registered engineers, £5M public liability insurance and Ambiente systems and manifolds. We work London-wide (see areas we cover), including Hampstead, Camden and Fulham. Book a site survey via our contact page (written quote within 24 hours, free) or see the full underfloor heating service page.

Retrofit FAQs

Retrofit Underfloor Heating Questions, Answered

What owners of existing London homes ask us before retrofitting wet UFH.

Yes. Low-profile boards are laid on top of your existing floor — no excavation, no new screed slab in most cases. The build-up adds around 15–25mm, often absorbed within the new floor finish or eased with a threshold strip.

Usually, yes — it avoids structural work and protects original features. Suspended timber, solid floors and mixed build-ups each need a different approach, which is why we survey before quoting.

Typically 15–25mm, depending on the system and any insulation layer beneath it. We measure door clearances and thresholds at the survey and coordinate finished levels with your flooring fitter.

A single room takes a few days; a whole house usually one to three weeks, including drying time where screed or levelling compound is used. Your free written quote includes a clear timeline.

Yes. The manifold's blending valve tempers a standard combi or system boiler down to the 35–45°C the floor needs. It is also the ideal partner for an air source heat pump — reconnectable later without lifting the floor.

Retrofit Warmth Into Your Existing Home

Site survey, straight advice on whether your floors are suitable, and a written quote within 24 hours — from Gas Safe registered, fully insured engineers.

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