Two neighbouring chalets built by ECSUS Design using SIPs have received top energy ratings, setting new eco standards in the French Alps.
Mountain properties traditionally suffer from poor energy performance due to the extreme climate. But Chalet Cote and Chalet du Cret in Essert Romand, near Morzine, have bucked the trend by achieving the top A rating for CO2 emissions and high B ratings for energy economy.
The certification puts the chalets in the top 2%, said local estate agents Alpine Property. Director Gareth Jefferies explained: “Those figures are certainly excellent. In general, the ratings we’re seeing in the Alps have not improved, despite buyers becoming more conscious of environmental impact. Of 172 chalets we’ve recently advertised most were below an E, with just 3 achieving grade B or above.”
Alpine chalet owners usually expect to set aside thousands for bills over harsh snowy winters. But the ECSUS Design team’s most recent construction, 39 Chalet Cote, has had its annual heating bills estimated at €318, and hot water bills €189, in a report by French thermal certification experts Consult’Imm. And with the overall build cost coming in at €2436 per sqm (without tax) – well under the average €3-4,000 per sqm for the area – the happy chalet owners are looking at significant savings now and in future.
The two properties were built by ECSUS for private clients and designed to make the most of stunning views across the valley.
The 256sqm Chalet Cote was liveable within 6 months; groundworks began in June 2018 and the owners moved in for a family Christmas – making it one of the fastest builds in the Alps, as well as one of the most eco-friendly and affordable.
The specialist team took just 6 days to erect the SIP structure. Speed of construction is vital in the Alps, as ECSUS Design director Steve Downs explained: “The building window is limited by the arrival of snow, and restrictions on work during tourist seasons – both summer and winter. Building can only usually take place between May and November.”
Chalet Cote and next door Chalet du Cret feature underfloor heating, air sourced heat pump, heat exchanger and triple glazing.
The 0.16 U-value (R-value 6.25) of the SIP 170mm panels is reduced further to 0.10 (R-value 9.7) with the addition of 100mm rockwool insulation and 13mm plasterboard in the roof. In the walls just 40mm of rockwool is used inside the service void behind the plasterboard to achieve a U-value of 0.13 (R-value of 7.6). This means the properties easily surpass the French RT2012 regulations for new builds of minimum roof R-value 6.5, and wall R-value 3.2.
The panels’ unique jointing system, as well as sealing and taping, allowed the chalet to achieve airtightness of 0.39 air changes per hour, which well exceeds the Passivhaus standard of 0.60.
Despite their high-tech SIPs structure the look of the chalets is very traditional, achieved using large purlins and Savoyarde-style roof overhangs. Inside and out, the finish is to luxury standard; Chalet Cote even features a lift as well as hot tub and sauna.
ECSUS now have builds at various stages across the Alps in Chamonix, Combloux, St Gervais, Morzine, St Jean de Sixt and more, to the same eco standards.
ECSUS Design director Steven Downs said: “We’re delighted to be able to offer a new eco-friendly option to people keen to build their dream ski chalet in the French Alps, while limiting their environmental impact, using SIPs. The SIP system, alongside other energy saving systems, allows us to build luxury chalets with eco credentials and an affordable price tag.”
Watch our Video Diaries of the construction of Chalet Cote: