Draw up a list of 3-5 builders you have decided to get a quote from. Ask the builder for a quotation for the works, if the works are building works i.e. an extension he will need a copy of the plans and notes to give you a set price. Never part with your only set of plans in case you never hear from him again, get them copied, although plans can be a bit dearer than normal copies because of their size and detail it will be worth it in the long run.
Extras however, can sometimes not be avoided, a contingency sum could be included to cover this. This would involve your tradesperson allowing a sum of money, i.e. 5% - 10% of the overall figure in case unforeseen problems arise. This could be something as simple as on stripping your wallpaper off damp (see our damp & rot section) may be found and your plaster is rotten. This will obviously have to be dealt with before the new paper is put up so more costs will be incurred. See our section on decoration for further information and advice.
If you have already used up all your budget on getting the basic works done this is going to cause you a problem, so it is always wise to allow for a contingency sum. Make sure the quote is detailed and broken down in price (this will help with payment schemes). For instance if each item is priced individually, you can see, as each item gets done, how much to date you owe your tradesperson.
Never accept a verbal quote, you have no proof of what was originally quoted for, the last thing you want is half a job done and when you query it, you are told "Oh I did not price for that, that will be extra". You can have a written quote, you can see exactly whats included. See our section on quotations for further information.
If you submit plans for local authority approval you can also expect a mountain of post from tradespeople wanting to price for the works. This is because a list of people waiting for planning permission is available to them.