YOU DON'T need to be Fred or Wilma Flintstone to enjoy living in a cave and today a growing number of people are doing just that and turning troglodytic caves into family homes.
There are no stalactites or stalagmites in these limestone wonders, as all the hard work has been done by hand, digging out the rooms to whatever size and shape needed.
It might look refreshingly new but since the 11th and 12th centuries people in many parts of France have settled in caves that have been extended underground.
Bernard Tobie, president of CATP (Carrefour Anjou Touraine Poitou), an organisation set up to promote and preserve the troglodytic heritage of the Anjou, Touraine and Poitou areas, said there were thousands of kilometres of underground caves.
You can no longer get permission to build a troglodyte house; you can only convert an existing one. CATP has been a go-between for people wanting to know more about buying, renovating or converting troglodytic caves into houses.
He said: “Troglodytic houses are dug houses; part of subtractive architecture, as opposed to built houses. They are dug, often out of nothing, into the rock: either inside a cliff – called a coteau – or, and this is the peculiarity of our region, Anjou, in the plain, dug into the ground vertically. There are more of the first kind than the second, but in Anjou we have both.
“Often, the troglodytic habitation has also evolved into an external built part that leans on to the cliff and extends it; what we call a semi-troglodytic habitat.”
Touraine has troglodytic houses in the chalky rocks called Tuffeau (tufa) limestone and the Falun soft shellstone. Tuffeau rock was laid down 85 million years ago, and was used to build the châteaux and houses of the Loire Valley.
“Falun is only around 12 million years old and was used only in the area of Doué.”
Mr Tobie added: “The interest of this type of house is the thermal insulation; temperatures inside are always around 13C, but there is also a certain inertia in the rock, so heating takes a little while, like in historical monuments. The rock is naturally humid, so there may be problems with humidity. This needs to be treated with good ventilation, but if it is well treated it becomes a very habitable place.
“Of course, it is also a toy-house which you can arrange as you want – with all the curves: it is completely original. It has the advantage of being perfectly integrated into the landscape and there is no intrusion of outside noise. You can really be at peace.
“Anyone with a creative mind looking for an original house will find dug houses have great potential for decoration and set-up.”
When his association was founded 37 years ago, troglodytic houses were not in fashion among wealthy professionals, but that changed in the 1970s, which saw a simpler mentality and return to nature.
Mr Tobie said: “As a habitat, it was considered for a long time like something of the past for people who were poor and could not afford anything else.
“Now it has switched to something that is back into fashion, but within current ecological and environmental consciousness. It is also a passive house in terms of energy consumption.”
Moving into a troglodytic house may seem like a good idea, but the difficulties of adjusting should not be underestimated.
It is a project that should be even more carefully planned than a standard house.
Indeed, the troglodytic habitat involves risks and dangers if they are not taken seriously and thought-out in advance.
Mr Tobie said: “The first thing you have to look for is the state of the rock, because there can be gaps in the rock and it can decompose.
“There is a risk of it collapsing. We know how to consolidate it, but is comes at a cost. Geo-technical experts can do that.
“Then there is the problem of land property: what do we own? The ground or the underground? “It is not always simple.
“The ideal is to own everything: the top and the bottom but we now have solutions to divide the land into volumes and find out exactly what you can and cannot own.”
According to CATP, there are some 15,000 troglodytic caves in Anjou and 45,000 in the Loire Valley, one of the most prolific parts of France.
Others, mostly unused underground caves, can be found in Gironde, the Dordogne and elsewhere, but they can be found all around the world.
“Theses caves have been around since the early Middle Ages. We can find them anywhere: Spain, Italy, Hungary, there are many in Cappadocia in Turkey, North Africa and all around the Mediterranean basin, not to mention India.
“China has more than 20 million people still living in them.
“It is a habitat that has existed for centuries and is a long-lasting one. It is often a ‘coup de coeur’ purchase, but you have to gather information very carefully,” Mr Tobie said.
“The current interest in France is due to sustainable development and the ecology. I do not think it is just a passing trend, but the future will tell.”
Underground house has views on to the Loire
Architect Jean-Claude Drouin returned to France after several years working in the US with a clear idea of where and how he wanted to live.
“I wanted to live in, not an old house, but something that would be more original. At the time, 35 years ago, people took us for eccentrics for wanting to live inside the rock.”
Mr Drouin built his semitroglodytic house in Rochecorbon, just outside Tours and said: “The reaction from our first visitors was one of surprise; now it is the opposite. It is a real trend: going back to nature, the idea of integration.
“Our three children lived their young years in this house.
“The view is exceptional. We overlook the Loire with its meanders and sand beaches.”
The site was part of land being sold off from a nearby chateau; a lower terrace of the vineyard with a greenhouse and small orangery. “I decided to restore the greenhouse, which leant on the coteau and attach it to the orangery by building the house between them.
“Now we have the kitchen in the troglodytic part and we dug the coteau so all the bedrooms have views on the Loire.
“We put the washrooms on a lower level to integrate all the equipment and to bring modernity into the cave and treat it in a contemporary way, with many colours, so there was a pleasant sense of life, even in winter.”
The house is more than 250m² and is heated by a heat pump that transfers the sun’s warmth from the greenhouse.
“When the cold days arrive, we put on a jumper, we light the fire. It is convivial. It is a lifestyle close to nature.”
Mr Drouin said there was a certain amount of maintenance, not much different from an old house, but he added: “There is also the problem of stability. You have to be careful because the rock is alive, so cavities can collapse after 400 or 800 years.
“Because we are in a society that does not tolerate risk and invents laws for the most minor risk, it is a problem that we try to understand and anticipate.
“Overall, it is more linked with the notion of pleasure. Some people only like the city and loathe nature; it depends on taste. For an experience like this. you need to be interested in alternative living, which is fun on top of it.
“We looked at leaving 30 years ago, but did not find any takers, whereas today people come forward to ask if we are selling. It has evolved.”