Underfloor Heating Costs in London

Typical London underfloor heating budgets

Three planning tiers for underfloor heating in London, with scope and a representative figure for each. Run your own numbers in the calculator for a tailored range.

Typical regional cost ranges

Indicative range: £50–£150 per m².

1. 1

   Thermal blanket / insulation board under the pipes

   Under EVERY underfloor heating install (wet or electric), there must be insulation between the pipes and the substrate — typically 50-100mm PIR (Celotex/Kingspan) for new screed, or 6-10mm slim insulation board for retrofit. Without it, 30-50% of your heat goes DOWN into the slab instead of UP into the room. Quotes that skip this 'to save cost' double your running bills forever.

   Fair UK range: £12–£25 per m² for 50-100mm PIR under-screed insulation. £8–£18 per m² for low-profile foil-faced retrofit insulation board.

   Ask: What insulation type and thickness is going UNDER the pipes, and what's the U-value performance figure?

2. 2

   Pipe / cable specification — manufacturer, type, and warranty

   A fair quote names the actual product: Polypipe Overlay, Uponor Comfort Pipe Plus, Wavin AdvancedHeating, Robbens Hydroflex (wet); Warmup, ProWarm, ThermoSphere (electric). The brand matters because the warranty is brand-backed (typically 25-50 years on the pipe). 'Standard 16mm PEX pipe' tells you nothing — it could be £2/m generic with 5-year warranty, or £8/m premium with 50-year warranty.

   Fair UK range: Wet UFH pipe: £4–£10 per linear metre supplied. Electric UFH: £20–£45 per m² for mat or cable. Manifold: £200–£500 supplied for a quality 6-zone (Polypipe, Wavin, Uponor).

   Ask: Which exact pipe/cable brand and product range, and what's the manufacturer warranty in writing?

3. 3

   Manifold, zone control and wiring centre (wet systems)

   A wet UFH system needs: a manifold (where pipes branch out), a wiring centre, individual zone actuators (one per room), zone valves and controls, plus a thermostat per zone. For installs over 50m², zone control is essential — without it, the whole system runs as one zone and you can't independently control different rooms. Many cheap quotes specify a single-zone manifold for a 6-room install — that's £400 saved upfront and £8,000 of comfort/efficiency lost over 20 years.

   Fair UK range: Manifold + wiring centre + actuators: £600–£1,500 for a 4-6 zone setup. Individual room thermostats: £50–£200 each (basic to smart).

   Ask: How many zones is this system, and is each room independently controllable with its own thermostat and actuator?

4. 4

   Screed laying and curing (wet systems) or floor build-up adjustment (retrofit)

   Wet UFH pipes are typically buried in 65-75mm of liquid screed (Gyvlon/Cemfloor) or sand-cement screed. Liquid screed is faster (1-day pour, 2-3 weeks before final floor) but premium. Sand-cement is cheaper but slower (4-6 weeks curing). Retrofit installs raise the floor level by 18-30mm (low-profile) or 50-75mm (new screed) — this affects door clearances, skirting heights, threshold transitions. Often missed in initial quotes.

   Fair UK range: Liquid screed: £25–£40 per m². Sand-cement screed: £18–£28 per m². Door reduction/threshold adjustments: £40–£100 per door.

   Ask: What screed type (liquid or sand-cement), what depth, and have you accounted for door/threshold height adjustments?

5. 5

   Commissioning, pressure testing, leak certification and handover

   Before screed is poured (wet) or final floor goes down (electric), the system must be: (1) pressure tested at 6 bar for at least 24 hours with documented results, (2) commissioned with flow rates set per zone, (3) heating cycle gradually ramped up over 2-3 weeks once screed has cured, (4) given a final commissioning certificate with thermostat programming. Skipping any of this is the #1 cause of leaks discovered AFTER £3,000 of tile is laid on top.

   Fair UK range: Should be £0 — included in any reputable installer's quote. Standalone commissioning by a third party: £200-£400.

   Ask: Will you carry out pressure testing at 6 bar for 24 hours BEFORE screed is poured, with photo evidence and a written commissioning certificate?

• No insulation specified UNDER the pipes

  Why it matters: Insulation under the pipes is the difference between a UFH system that costs £400/year to run and one that costs £900/year. Heat radiates in all directions — without insulation below, 30-50% goes into the slab. Quotes that skip 'to save £15/m²' cost you that money back in 2-3 years of running, then keep costing forever. This is the #1 spec error in cheap UFH quotes.

  Ask: What insulation thickness and type goes UNDER the pipes, and where is it shown on the quote?

• No pipe-laying photos or floor plan with pipe layout shown

  Why it matters: A reputable installer produces a CAD or hand-drawn floor plan showing pipe loops, manifold position, and circuit lengths (max 100-120m per circuit). They take photos before screed is poured. If neither is in the proposal, you have zero comeback if a leak occurs — nobody knows where the pipes run, so finding the leak means breaking up the entire floor.

  Ask: Will you provide a pipe layout drawing before install, and photographic evidence of the pipework before screed is poured?

• No pressure testing or commissioning certificate mentioned

  Why it matters: Pressure testing at 6 bar for 24+ hours BEFORE screed pour is the only way to verify there are no leaks. Discovering a leak AFTER screed is set means demolition of the floor — minimum £2,500-£5,000 of remedial work. Commissioning certificate documents the test results, flow rates per zone, and proves the install is sound. No certificate = no proof = no warranty enforcement.

  Ask: Will you pressure test at 6 bar for 24+ hours pre-screed and provide a written commissioning certificate with results?

• Single-zone setup proposed for a multi-room install over 50m²

  Why it matters: A single-zone manifold means every room runs at the same temperature — bedroom too hot, lounge too cold, no way to fix it. For installs over 50m² or covering more than one room, individual zone control (one actuator and thermostat per room) is essential. Cheap quotes save £300-£500 on zone hardware and you live with the comfort/cost penalty for 25 years.

  Ask: Why is this proposed as one zone? Can you cost a multi-zone version with one thermostat per room?

• Wet UFH connecting to existing gas boiler with no Gas Safe registration mentioned

  Why it matters: Connecting wet UFH to a gas boiler is gas work — it requires a Gas Safe registered engineer. If your UFH installer is not Gas Safe, they need to bring one in (often costs £200-£500 in coordination). A quote that doesn't address this is either: (1) planning to do gas work illegally, or (2) about to charge you 'extras' for the Gas Safe sub-contractor.

  Ask: Who's doing the boiler connection work — are they Gas Safe registered, what's their ID number, and is this cost included?

• Electric UFH install with no NICEIC/NAPIT registration mentioned

  Why it matters: Electric UFH installation is notifiable under Part P of Building Regs. The installer must be NICEIC, NAPIT or STROMA registered, OR notify Building Control separately (£200-£500). They also need to issue an Electrical Installation Certificate (EIC). No registration = no Part P certificate = the install is non-compliant and a problem at house sale.

  Ask: Are you NICEIC/NAPIT registered for the electrical work, and will you provide an EIC and Part P notification?

• Quote doesn't mention floor build-up height or door clearance adjustments

  Why it matters: UFH adds 18-30mm (low-profile retrofit) to 75mm+ (new screed) to your floor height. This affects: door bottoms (need trimming or replacing), skirting heights, threshold transitions to other rooms. Quotes that skip these add 'extras' mid-job for £40-£100 per door, plus skirting reinstatement. Get it in writing upfront.

  Ask: What's the total floor build-up height from existing substrate, and are door reductions, skirting and threshold work included?

1. 1. Are you a manufacturer-trained installer for the system you're quoting (Polypipe, Uponor, Wavin, Warmup etc)?

   Why it matters: Manufacturer training (Polypipe Approved Installer, Uponor PRO, Wavin Sentio Specialist, Warmup Installer Network) is what underwrites the long-term pipe/cable warranty — typically 25-50 years on the pipe. Without it, you have only consumer-level warranty (often 5-10 years). Verify on the manufacturer's own 'find an installer' page, not just the installer's word.

2. 2. Are you a member of the UFH Manufacturers Association (UFHMA) or BEAMA Underfloor Heating Group?

   Why it matters: UFHMA is the trade body for the UK UFH industry. Membership means: code of practice adherence, technical training, and dispute resolution. Not the only signal of quality, but absence + no manufacturer training is worth a second look.

3. 3. If connecting to a gas boiler: what's your Gas Safe ID, or who's the Gas Safe sub-contractor?

   Why it matters: Wet UFH connection to a gas boiler is gas work and legally requires Gas Safe registration. Either the installer holds it (verify at gassaferegister.co.uk) or they bring in a Gas Safe engineer (whose details you should have, with cost included). 'We'll sort it on the day' is a red flag for unauthorised gas work.

4. 4. If electric UFH: what's your NICEIC/NAPIT registration number, and will you issue an EIC and Part P notification?

   Why it matters: Electric UFH is notifiable electrical work under Part P. Installer must be NICEIC/NAPIT/STROMA registered (verify at niceic.com or napit.org.uk) and must issue an EIC plus Building Control notification. No registration = non-compliant install.

5. 5. Will you provide a pipe-layout drawing before install and pre-screed photos of the pipework?

   Why it matters: Documentation is what protects you when leaks happen 5-15 years later. The drawing tells the future plumber where pipes run; the photos prove the install was done correctly before being buried. No documentation = if a leak occurs, the entire floor must be lifted to find it.

6. 6. Will you pressure test at 6 bar for 24+ hours before screed is poured, with photographic evidence and a written commissioning certificate?

   Why it matters: Pressure testing pre-screed is the ONLY way to confirm leak-free pipework before it's permanently buried. The certificate is your documented evidence the install was sound on day one. Without testing, leaks discovered post-screed mean £3,000-£5,000 of demolition work.

7. 7. What's your installation warranty on workmanship (separate from the pipe/cable manufacturer warranty)?

   Why it matters: UK norm is 5-10 years on workmanship for UFH (manifold leaks, joint failures, controls issues caused by them). Manufacturer warranty on the pipe itself (25-50 years) is separate. Less than 5 years on workmanship is below industry standard.

8. 8. How will the system be zoned, and how many independent thermostats are included?

   Why it matters: For installs over 50m² or multi-room, individual zone control is essential for both comfort and efficiency. A reputable installer recommends one zone per room (or per heating need); cheap quotes propose single-zone setups that hand you 25 years of poor performance.

9. 9. What floor build-up height am I adding, and have door clearances and threshold transitions been costed?

   Why it matters: UFH adds significant floor height. A reputable installer measures door bottoms, plans threshold transitions and includes door reductions in the quote. Vague answers mean £40-£100 per door of unbudgeted 'extras' mid-job.

10. 10. Are you VAT registered, and do you carry public liability insurance at £2M minimum?

    Why it matters: VAT registration suggests genuine business turnover (£85k+ threshold). £2M public liability is the UK industry baseline — water damage from a UFH leak can easily exceed £50,000, and you need that cover behind you. Ask to see the certificate.

Compare other regions

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Frequently asked questions