In Dordogne, a hotelier paints his roof with lime to fight the heat without air conditioning
‘We have reduced the temperature inside the buildings by 4C to 5C’
Published
A hotel director in Dordogne, faced with the extreme heat, decided to cover the hotel’s roof with lime in an attempt to reduce indoor temperatures without installing air conditioning.
“I had been thinking about it for four or five years,” Gilles Roby, director of the Hostellerie du Périgord Vert, told The Connexion. “The extreme temperatures at the beginning of the summer convinced me to finally try it.”
The hotel, located on the banks of the Dronne river, does not have air conditioning. As temperatures increased, Mr Roby began worrying about the impact on his guests.
“We started to see the first room cancellations coming because of the heat,” he explained.
The idea came from observing traditional Mediterranean buildings in warmer regions. “In Mediterranean countries, houses are often white because they absorb less heat,” he said. “I thought that if white walls help, maybe white roofs could do the same thing.”
He then contacted a lime producer who confirmed that the technique could be used on the roof.
How much does the treatment cost?
The treatment covered around 1,000 square metres of roofing and according to Mr Roby, the cost was relatively small compared with installing air conditioning.
“I spent around €70 on lime, plus around €500 for the equipment,” he said.
On the hotel’s Facebook page, he documented the entire process through several videos, from preparing the mixture to applying it to the roof.
“The goal was to do something more collaborative,” he said. “I shared the method I used because people can get information and try to adapt the idea themselves.”
Since applying the lime treatment, Mr Roby said he has seen a noticeable difference. “We have reduced the temperature inside the buildings by 4C to 5C,” he said.
For him, one of the main advantages is that the solution requires no energy once applied.
“It is a relatively ecological solution. It does not damage anything, and the lime will eventually disappear over time.”
One guest who stayed at the hotel during a hot period also shared a positive review online:
“Incredible! The rooms and the building are cool without air conditioning. Thanks to the lime-washed roof, you don't feel hot despite the 38C outside. The food is delicious and the welcome is very friendly… Make the detour to this magnificent village!”
An alternative to air conditioning?
While Mr Roby is not against air conditioning, he believes other solutions should be considered first.
“Before installing air conditioning, we should try other, more sustainable solutions: insulation, anti-UV films, and increasing the roof’s ability to reflect heat.”
He believes the technique could also help buildings that already have air conditioning.
“Someone who has air conditioning would probably need to use it much later if their home is cooler to begin with.”
A solution that still needs testing
However, Mr Roby also admitted that his experiment is still in its early stages. Because he has not added resin coating, the lime treatment will not last permanently.
“It will disappear by the end of the season, and we will probably have to do it again next year.”
A resin could potentially improve the durability of the treatment, but more research would be needed to know exactly how long it could last.
“We accept being pioneers,” he said. “The process and the products may evolve.”
However, as heatwaves become more frequent, he believes it is important to explore alternatives.
“There is nothing revolutionary about it,” he said. “It is simply adapting to climate change. The climate is changing, so we also need to change our habits.”
