Our services

Heating replacement study

The core product for an owner. We take the meter readings and the building data, from a questionnaire or a site visit, then compare the variants that are realistic for that building : air-to-water heat pump, ground-source heat pump on boreholes, district heating, wood, or a hybrid. Each is set out with its investment, its annual cost over twenty years, its CO2 and the subsidies it qualifies for, plus the permit route and a programme. The report is delivered in three weeks and presented to you or to your condominium meeting.

Heat pumps : sizing, noise and permit

Sizing comes first : heat demand to SIA 380/1, heating power to SIA 384/201 and domestic hot water to SIA 385/2. SIA is the Swiss engineers' and architects' association, whose standards the cantons apply. An oversized machine is the commonest fault we correct — it cycles, loses efficiency and makes more noise.

Noise is what actually blocks outdoor units. Since 1 November 2024 the sound power level at 2 °C outside air is the determining figure, night-time governs, and the assessment point is the middle of a neighbour's open window. A re-entrant corner of a façade costs about 6 dB before you start ; a hood buys roughly 3 dB, night mode 5 dB and an acoustic screen 6 dB. We produce the official justification on form LN-1a and say whether the unit needs a permit, a notification or nothing.

For eight new houses over a shared underground car park at Trélex, completed in 2026, we sized one 8 kW air-to-water heat pump per house, specified the car park ventilation with carbon monoxide and nitrogen oxide detection, and compared nine tenders. At Orbe a new house is fitted with a 12 kW reversible air-to-water unit on R290 propane, with cooling through the floor circuits.

Ventilation and indoor air

In Vaud, cantonal regulations require the energy service's authorisation from 1,000 m³/h of extracted air per building, and heat recovery becomes compulsory beyond that threshold. For dwellings, SIA 382/5:2021 sets 30 m³/h of supply air per room and at least 50 m³/h of extract air per dwelling unit in continuous operation ; other building uses follow SIA 382/1. We design single-flow extract and double-flow systems with heat recovery, and we check the acoustics and the ductwork before the tender, not after the complaint.

Energy balance and permit files

In the canton of Vaud a project is submitted through the mise à l'enquête, the public consultation, and CAMAC — the cantonal clearing house — circulates the file to the cantonal services. We prepare the energy part : the SIA 380/1 balance and the EN-VD forms, the standard cantonal energy forms. In Geneva the OCEN, the cantonal energy office, expects a building energy concept, with the IDC heat consumption index for existing buildings. A heavy renovation, meaning works above half the building's insured value, triggers full envelope compliance, so the balance has to be done properly from the start.

Energy certificates, Minergie and subsidies

The CECB is the cantonal building energy certificate, graded A to G, known as GEAK in German-speaking Switzerland ; the CECB Plus version adds a costed renovation scenario. The practice is a certified CECB expert and issues both. We are also a member of the Minergie association — the Swiss low-energy building label, with its stricter Minergie-P and Minergie-ECO variants — and take projects through certification.

Subsidies under the Programme Bâtiments must be applied for before the works begin, and a CECB Plus is often a precondition. One trap costs owners the whole grant : for measures up to 70 kW, no fossil back-up is tolerated, so a small gas boiler kept "just in case" disqualifies the heat pump.

Tenders, site supervision and turnkey mandates

We write the specifications, run the tender, compare the offers line by line, then supervise the works, witness commissioning and check the settings. The modular six-classroom school pavilion in the canton of Geneva ran this way : a 24.3 kW air-to-water heat pump, radiators at 40/35 °C, an 800-litre buffer tank and BIM construction drawings.

On a turnkey mandate we take the whole sequence — permit, tenders for all trades, programme, site management, handover and the subsidy file — while you keep the decisions and the payments. See our French page on the turnkey project.