Chauffage Isolation

Line up quotes on scope before price: the insulation thickness and material, the treatment of junctions and openings, the equipment model and output, the emitters kept or replaced, the removal of the old system and the commissioning report. A quote that only names a product leaves too much room for interpretation once the site opens up.

Ask what happens if the survey reveals hidden damp, an unsuitable flue or a floor build-up too shallow for the planned insulation. Agreeing in advance how such findings are priced avoids a renegotiation mid-works. Also check who applies for the aid available through Klimabonus Wunnen, which documents you must supply and at which stage they are needed, since the paperwork depends on the works being described in a specific way.

Insulation and heating are best planned together, because the size of a boiler, heat pump or radiator circuit depends on how much heat the building actually loses. Improving the roof, walls or floor first usually lets an installer specify smaller, quieter equipment, while doing the opposite risks paying for an oversized system that never runs at its best. Ask each company to explain which order it recommends for your dwelling and why.

Practical details matter as much as the equipment itself: where the indoor and outdoor units can be placed, how condensate and existing flues are handled, whether the distribution circuit needs balancing, and how the airtightness layer will be sealed around junctions. Companies that describe the commissioning and handover steps, not just the hardware, are usually the ones whose quotes hold up on site.

This category brings together three types of work that shape a home's comfort and energy use. Heating comes first: boilers, underfloor heating, water heaters, boiler servicing, stoves, fireplaces and inserts, heat pumps, and chimney sweeping. Air comfort follows: air conditioning, air purification, ventilation. Insulation completes the picture: ecological insulation, acoustic insulation, loft insulation, internal wall insulation, airtightness and external wall insulation.

These three strands are connected. Replacing a boiler without first addressing insulation often means oversizing the new appliance to compensate for avoidable heat loss. Conversely, insulating without reviewing the heating system can leave an old appliance mismatched to the home's new, lower needs. A coherent renovation project looks at the building envelope before sizing the heating equipment.

Some interventions follow clear obligations or technical necessity: regular chimney sweeping, annual boiler servicing, and any work on a gas installation must be entrusted to an authorised professional. A heating engineer is also the right contact for sizing a heat pump, connecting underfloor heating, or diagnosing a hot water fault.

For insulation, a professional becomes necessary once the work touches the building structure: fitting insulation under the roof, external wall insulation with render or cladding, or treating airtightness at the junctions between walls, floor and roof. These junctions are exactly where poor workmanship creates thermal bridges or damp problems.

A heating project starts with a technical visit: assessing the existing installation, the required output, and access or flue constraints. A detailed quote follows, then the equipment order and the work itself, ranging from a few hours for a service call to several days for a full boiler replacement or heat pump installation. Commissioning and, where relevant, a compliance check close out the job.

An insulation project follows a similar pattern: diagnosing heat loss, choosing the material and technique suited to the substrate, preparing the site, installation, and finishing work. Loft insulation for an unconverted attic is often done in a day, while external wall insulation with full render renovation can take several weeks and requires scaffolding.

For heating, the required output, the energy source, the complexity of the hydraulic or electrical connection, and how easily the home can be accessed all affect the final cost. Replacing an old boiler with a more efficient model sometimes requires adapting the distribution network or the flue, which should be spelled out clearly in the quote.

For insulation, the area to be treated, the thickness and type of material, the installation technique chosen and the condition of the existing substrate are the main factors. External insulation costs more than internal insulation for the same area, but it handles thermal bridges better and does not reduce living space.

Klimabonus Wunnen, which replaced the former PRIMe House programme in 2022, supports both replacing a heating system with a more efficient one and insulation work on the building envelope. Exact amounts and eligibility conditions, which depend partly on the performance achieved, are published on guichet.lu and should be checked before starting work, as some grants require an application before the site begins.

Check that the company holds a business permit for the relevant trade and professional liability insurance. Ask for detailed quotes specifying the equipment, its brand and model, labour, any related work such as flue adaptation or render repair, and the timeline.

Compare quotes on a like-for-like basis: two quotes for the same insulated area can cover very different thicknesses or materials, just as two heat pump quotes can list outputs that do not match the same actual need. Describe your project once on vert.lu and we pass your request to companies in our directory active in heating and insulation in your area; those available will get in touch to arrange a visit, with no obligation on your part.