Planning water-based underfloor heating for a new home, extension or renovation? You do not need to choose pipe spacing before your first conversation with an installer. Start with the rooms you want to heat, the floors you want to keep and the information you already have about your home.
Use the table and six lists below to prepare for a quote. Copy them into your notes or print this page. Beside each item, write ready, to confirm or not applicable. Add who will confirm any missing information. You can use the checklist without an account or a HeatAlgo purchase.
This guide covers heating with water circulating through pipes beneath the floor. Electric heating mats are outside its scope. You gather and check the project inputs; your installer reviews the proposed design for your property and the selected system before installation.
What is ready for your quote?
In your copy of the table, keep one status per row. Replace the example documents with your own file names or notes and add the person who will confirm the information. If anything is unknown, choose to confirm and describe the gap. The six sections below explain what to gather for each row.
| Information needed | Status - choose one | Supporting document | Person confirming |
|---|---|---|---|
| Floor plans, measurements and fixed features | ready / to confirm / not applicable | Dated or revised plan, measurements and marked changes | Add a name |
| Floor construction, insulation and available height | ready / to confirm / not applicable | Floor build-up drawing, product sheets or site inspection notes | Add a name |
| Floor finish for each room | ready / to confirm / not applicable | Covering, underlay and adhesive specifications and manufacturer conditions | Add a name |
| Heating system and room heat loss | ready / to confirm / not applicable | Equipment details, heat loss calculation and planned changes to the home | Add a name |
| Manifold location, pipe routes and controls | ready / to confirm / not applicable | Plan with proposed locations and notes on obstacles | Add a name |
| Quote scope, checks and handover | ready / to confirm / not applicable | Agreed scope of work and questions for the installer | Add a name |
1. Floor plans, measurements and fixed features
- A plan for every floor included in the work, with its date or revision.
- Room names, intended uses, dimensions and ceiling heights.
- At least one measured dimension on each plan so its scale can be checked. Note whether other dimensions come from drawings or site measurements.
- Doors, stairs, kitchen units and island, sanitary fittings, fireplaces and other fixed features marked on the plan.
- Walls, doorways or room layouts that may still change.
Mark the rooms where you want underfloor heating and any areas you want to leave untouched. Fixed features are points to discuss with the installer, not a universal rule for where pipes may go. If a drawing no longer matches the house, flag the difference.
2. Floor construction, insulation and available height
- Whether the floor is solid or suspended, if known.
- Existing floor layers and insulation material and thickness, supported by drawings, specifications or photos where available.
- What will be retained, removed or rebuilt, and any known damp or floor-condition concerns.
- Available height for the complete new floor, including the finish, at doors, stairs, thresholds and adjoining rooms.
- Who will check the existing floor and confirm the proposed build-up.
Do not choose a system by its advertised panel thickness alone. Ask for the full floor build-up and the resulting finished floor levels. A solution for a new slab may need a different approach in a renovation. What the layers of a building element and the insulation thickness mean in your documents is explained in the heating glossary for clients. How much insulation goes under the pipes, and how much heat goes down with only the minimum, is calculated in how much insulation under underfloor heating. Leave unknown layers marked to confirm.
3. Intended floor finishes and product specifications
- Your preferred finish in each room: tiles, timber, vinyl, carpet or another material.
- The manufacturer, exact product and thickness where already chosen.
- Underlay and fixing or adhesive specifications, where applicable.
- The supplier's confirmation of suitability for water-based underfloor heating, thermal resistance information and any temperature limits or installation conditions.
- Rooms where you are still choosing between finishes.
Share the product sheets before the heating design is finalised. Ask the installer to check the proposed covering and heating output together. How much output the covering takes away, and why timber or carpet deliver less than tiles, is explained in the guide on underfloor flow temperature. A label saying "suitable for underfloor heating" is still a reason to read that product's conditions.
4. Heating system and available heat-loss information
- The existing or proposed boiler or heat pump, with model and specifications if known.
- Rooms that will retain radiators or another form of heating.
- Any room-by-room heat loss calculation, with the building details and assumptions used.
- Planned changes to insulation, windows, room use or ventilation.
- Who will check the heat needed in each room against what the proposed heated floor can deliver.
Room area alone does not describe heat demand. What goes into a heat loss calculation and what the result depends on is explained in what a heat loss calculation is. If you have no calculation, say so and ask who will provide it. A HeatAlgo report is not an MCS heat loss calculation. Do not guess insulation values or select a water temperature just to fill an empty field.
5. Manifold locations, pipe routes and room controls
- Possible locations for the manifold, the unit that connects the pipe loops, with space for access and servicing.
- Possible routes between the manifold and each room, with doorways, changes of level and other obstacles marked.
- Rooms you would like to control separately and how you expect to use them.
- Possible thermostat locations and any known wiring constraints.
- Areas that must remain available for furniture or storage.
Treat these as suggestions until checked. Ask the installer to include the pipe runs to and from the manifold in the loop design and to confirm access, connections and controls. Why the run to and from the manifold counts towards loop length is shown in the guide on pipe spacing and loop length.
6. Quote, design responsibility, checks and handover
- Who prepares the heating calculations and layout, and who reviews them for the actual property and selected system?
- Which drawings, assumptions, pipe specifications, loop lengths and design settings will be documented?
- Does the quote include floor preparation, insulation, pipework, manifold, controls, heat-source connections and floor reinstatement? What is excluded?
- Who coordinates the heating installer, screed contractor and flooring installer, and how are changes priced and agreed?
- Who carries out and records the pressure test before the pipes are covered, following the selected system's instructions?
- Who handles commissioning, flow adjustments, controls checks and the initial heating procedure required for the floor construction?
- Will you receive the final layout, loop labels, test and commissioning records, operating instructions and relevant warranty information?
Keep the answers with the quote so you can compare the scope of different offers. Agree the checks before work starts: EN 1264-4 provides for a pressure test before the screed is laid. Ask your installer for the instructions applicable to your chosen system, rather than copying test settings from another product.
Choose your next step
This checklist helps you gather inputs before a quote or design. Choose the next guide for the question you need to answer:
- Already have a design or quote? Read what an underfloor heating design should include and compare the documented scope.
- Want to understand the pipe layout? Read about pipe spacing and loop length, including the runs to and from the manifold.
- Deciding where the manifold goes? See how two manifold positions change the pipe runs on one floor.
- Choosing your floor finish? See how flow temperature and floor coverings affect heating output.
- Renovating an existing home? Read what to measure before retrofitting water-based underfloor heating, with a worksheet for floor levels and layers.
- Have your inputs and want to start in the software? Follow how to use the underfloor heating module in HeatAlgo.
Prepare your plan in HeatAlgo
Once you have gathered the information, you can prepare a water-based underfloor heating project in HeatAlgo's underfloor heating design software. You provide and check the inputs and review the layout. You can then buy the printable plan and PDF report to discuss with your installer, who should review the proposed design for your home and selected system before installation.
See how to prepare your plan and report