The French devis is a priced quotation based on estimated quantities, whereas the UK quote is generally a lump sum quotation that is 'all-in' and is normally considered to cover all costs. The difference may seem to be nit picking, but in practise this can make an enormous impact on the way costs are managed during the building works. If you treat a French quotation as an 'all-in' price, you may be surprised to find that your final bill contains items that were not in the original quote. You may (and yes it does happen) be pleased to receive a cheque back from the builder for work that he estimated, but which proved to be less than anticipated. However, you will normally be presented with an invoice, the facture, which is more than you expected, and contains some items that you had not seen before. The artisan will shrug his shoulders at your mystification, because for him the matter is quite clear; he quoted you y euros for x number of square metres, and if x has become bigger, then so is the bill . . .

In a UK contract or schedule of works (which does not have a Bill of Quantities) the work is often described as works specified and implied! This means that the British contractor is obliged to consider matters that may not be explicitly described, but without which the remainder of the works cannot be undertaken. For the French contractor, if it is not set out in his devis then it is not included. This does mean that it is extremely important to understand exactly what is being quoted for in France. It also means that there is quite a bit of work needed to be able to compare quotes properly, as you have to make sure that each artisan is using the same quantities.

I understand that this is because of the difference in basic law, in that French law is statute derived, whilst UK law is derived from precedent ie case law. Whatever the reason (and I am not a lawyer) it requires a slightly different approach when trying to obtain prices for your building project.

Let me try to explain with a few examples.

I would like to put a small extension onto the side of my house in Henfield, in West Sussex. I have permission from the Local Authority, and I have some drawings to show the size and shape of the extension. There are notes on the drawings to describe the size of rafters, the type of windows and the height of the walls etc, and I have given these to three local contractors who have offered to tender. The tenders come back. Unless the project is particularly complex, I will receive a single figure from each contractor, and this will become the contract sum. Each contractor is supposed to have priced from the drawings and specification and to have allowed for all matters necessary for the construction. Unless I change the design or specification, or unless the contractor has made specific exclusions (size and depth of foundations for example) the price at the end of the day will be the one quoted.

In France, I would like to put a small extension on the side of my house in Honfleur. I also have drawings for which I have permission from the Mairie, and I have asked a group of artisans to provide their quotations - the devis - for the work. The first difficulty is that I must ask for separate quotes from the mason, carpenter/roofer, plasterer, electrician and plumber (never mind the painter, tiler, metal worker or joiner) and make sure that they each quote on the same basis. I cannot compare a quotation from a plumber who includes drains all the way to the first manhole with another plumber who quotes only to ground floor level. Has the mason quoted for the guttering or is it the plumber? If the blacksmith has provided the railings, will he fit them or does the mason have to do it? Each quotation has to be compared and assessed to ensure that I am comparing like with like. In this respect, the French builders are thorough, and their quotations will describe all the work in precise detail.

Having determined which UK builder or French artisans have offered the best quotations, work begins.

In Henfield, I find that a mistake on the levels means that an extra course of blocks is needed to get above ground. The British contractor is unhappy, but it was his responsibility to check this at the outset and he must swallow the cost. In France, the same problem will cause an increase in the cost for block-work. On the principle that the UK contractor has offered a lump sum price, unless the work is clearly extra or excluded from his quote, he is bound to provide it.

Not so in France. If the work is more than set out in his devis then it will be charged accordingly even if the devis is for less than would have been required anyway! Beware a quote that is low, as it may be that the builder has under-estimated the quantities.

In the UK, you may find that the builder will be on the lookout for extras that will allow him to recoup any perceived loss, but in France there is not this feeling, as the artisan will feel secure that his work will be paid for in any case.

To continue with our comparison, I decide that I will use a cheaper type of joinery in France to off-set the extra cost of block-work. Looking through the devis of the menuisier, I can clearly see the cost of each item. By asking him to change an oak window to one made of pine, I can make some small savings. The British builder will look at me rather blankly if I try this in Henfield. His quotation is lump sum, and whilst he may have priced it (perhaps on the back of an envelope) he will not be willing to show me his sums. Of course, I can press him on this and force an answer, but in some respects this will be unfair. I did not ask him to price my bill of quantities, which fully sets out all the materials and amounts needed, and for him to provide this requires a considerable amount of his time. On larger projects this is the normal way of pricing, but for smaller works it is rarely undertaken.

So what effect does this have on the work? The answer is 'none', but it does change the way in which costs can be controlled before and during the construction process.

To begin with, it is very much easier to compare quotations from UK builders. They will generally be a single figure with a few conditions and caveats, and will be based on the information you supplied. In France, you will have to wade through more quotes (one from each trade) and they will be set out in great detail. You will also have to ensure that the detail is the same! If you wish to stay within the price quoted by a British builder, don't alter the work in any way after he starts. Even this may not be sufficient, but I can practically guarantee that any change will result in an increase, rather than a decrease, in costs.

You must think ahead
The cost of a project is critical to its success. From my experience, I know that any over-run in costs will affect those parts of the building that are most visible; floor, wall and ceiling finishes and the standard of fixtures and fittings. These are the parts of a building that we most respond to, and I feel it is a great shame if the appearance is compromised by costs incurred by misunderstandings at the outset. Plan ahead, and the end result will stand a much better chance of satisfying your aspirations.