Building in solid stone :
Stone is healthy and not expensive !

Daughter of the caves whence came man, sister of raw earth and woods, source of inspiration for concrete and parent of stapled stone, building in solid stone is starting up again thanks to the strong will of a few indomitable Architects and Stone Masons. Following in the spirit of this technical number dedicated to the healthy habitat and protection of people, we met one of them in Marseilles, whom we first of all questioned about his motivations and then whether he thought that stone was a healthy material. As the interview went on, we asked about the advantages of this material, what was its future and what was holding up its expansion, etc.

… François Gauthier is one of those odd architects who keeps wanting to build in solid stone. On his worksites, he even manages to prove that, in certain conditions, it is cheaper to use than concrete and stapled stone and can be put on the specifications of social building.

However, that is not so for all architects ?
Yes and no. Indeed, it is not the case for many architects considering their active knowledge. I would even go so far as to say that it only concerns a small number of architects who are mainly in the ranks of Architects od France or those who were at Chaillot school. Yet I believe that the desire to build in solid stone is within each architect. It comes from our training in which stone is considered as fundamental. It is, moreover universally fundamental if we take into account the millions of tourists who come to France to see our old stones. Do not forget that in France over the two centuries comprising the Middle Ages, we extracted and worked on as great a volume of stone as did the Egyptians in a dynasty.

How did you manage to build with solid stone for the first time ?
The opportunity arose a few years ago with an employer who had an open mind about the arguments of the intrinsic quality of the material.

What quality do you mean ?
It is a material that is ready-made and does not need changing : we can work on the material but not alter its structure. It is a bearer of memories : a symbol of eternity, a noble, rich and prestige material. It is also the material of all works of art.

Is it by using these arguments that you succeeded in imposing building in solid stone ?
In our experience they are the arguments we put forward. However we tried to prove that it is illogical that stapled stone should be less expensive than solid stone because what is costly in building is the labour. This worksite enabled us to prove that building in solid stone can be economical. Compared to stapled stone which requires four workstations & emdash ; breezeblock wall, stapled stone, double inside insulation, finishing &emdash, it only requires three workstations used in relatively thin thickness (20 cm), the stone wall, which is also the outer facing, the double inside insulation and the finishing. When you use it in greater thickness, stone is even more economical as it requires no insulation and can also be used as inside facing.

Economical in labour costs, long-lasting, is this not also a very healthy material ?
It is natural. It exists.

A clean material ?
Yes, even if we can question this point when talking about the whole sector. It does not generate much waste, upstream, when being quarried or, downstream, on the worksite. Even when there is waste, there are people who can re-use it.

What about energy ?
I would say that it is one of the materials which consumes least energy. It is ready-made. It does not have to be made, its structurs does not have to be altered ; you just have to extract it and work on it. What is more, you must think of it in terms of time and we know that it lasts hundreds of thousands of years.

In this context, the matter of closing down quarries is rather strange.
I wonder if it is not a false problem. I think it is very diffecult, even for the Minister of the Environment, to make a decision until an efficient and exhaustive study has been made, including going round the quarries to determine that for so many m2 of stone used for building it is necessary to open so many m2 of quarries. As long as this question has not been answered I wonder how the minister or other persons can come to a decision. It is a debate concerning the environment and landscape.

To finish with this argument about " healthy material ", have you ever tried to re-use old stones in your buildings ?
For the time being the question has not been dealt with, but why not as a " sign " ?

In spite of all its advantages, is not stone a little restrictive in terms of architectural design, for example ?
The choice of a material is a constraint we give ourselves, that we work with. In architectural design, whatever the material, what interests us is finding the best synthesis between programme and constraint, and finding the best formal and coherent expression, without outside influences. We strive to treat each material in its own logic.

But what about regulations ?
Regulations are enforced whatever the material used. Do not forget that our job consists in obtaining the best possible expression from all the restrictions imposed on us.

What about the anti-earthquake factor ?
In certain cases we can talk about the limits of architectural creation. The rules are set out for building work which does not have the same behaviour as stone building. We try not to be closed. Yet earthquake-resistant regulations seem to me to be a false problem. There have always been earthquakes and man has always used stone for building.

Is it not strange that we do not know more about how ancient man built in stone ?
It is amazing. We have never has so many tools for analysing, studying and trying to understand solid stone building and yet we are still no better informed.

Therefore it is hard to explain why stone buildings have lasted so long ?
Scientific tools enable us to state that it is well built without really knowing why.

Yes, but the material itself is long-lasting.
The material is long-lasting, although it must be used with a certain know-how for it to last a long time. In olden times people really knew how to build so that buildings would last a long time. They had knowledge of the material that has been more or less lost. On the other hand, we do not know exactly what their design tools consisted of.

How can you place the demand for stone houses with regard to houses in timber frames or adobe ?
In the South of France, stone is a little like wood. We note that there is a demand for houses in the higher range. Compared to stone houses, the demand for houses in adobe is much more limited. There was demand for houses like Mexican houses.

So you think that building in solid stone has a better chance of development than other materials ?
In the South, stone is more popular than wood. Because of the wind and the sun here people prefer something heavy, whereas wood is light. It is a cultural issue because as soon as you move up from Avignon, wood is accepted much more easily.

What do you think it needs for building in stone to develop more ?
We must break the reflex : " stone is expensive " !

What should be done to achieve that ?
The trade should try to link up supply and demand by developing an attractive economical offer for lower range buildings to prove to the general public that stone is no more expensive than other building materials. Then everyone would want to build in stone.

Would that be enough ?
I think that today we must use every possible opportunity to encourage the use of stone. In view of the economic situation of the stone trade and all the dangers that that represents for those who have the skills, every initiative must be encouraged.

You seem very affected by this question.
I must say that I am, because I have great respect for those who have the skills and I consider them to be like the heirs of the builders of cathedrals. Their know-how is not disembodied culture. They have the gesture. They still have the gesture.

Do you believe in the future of Stone Masons ?
I think that a revival of the sector must use all the vectors at its disposal, whether it be experimental social building, small houses, megalithic architecture …. Even if the stonemason hardly comes into it. Making it known is experience. Increasing the use of stone can only bring it to the foreground, open up markets, trigger off decisions to buy it. If, little by little, we break the reflex of thinking that building in stone is expensive, then I think we will have taken a great step forward and a large sector of the market where a stonemason can use his skills will be opened up. The stone mason will work more and more as stone will be used more and more.

What would you say to a young architect who would like to build in stone ?
I do not know if I would be able to give him good advice. He has already seen our history, our trades. I would say that there are shapes to be found ; that due to the development of comfort, atmosphere is no longer fundamental because it can be controlled more easily ; that stone houses are not only for wealthy people ; that public equipment can be made with concepts.