Thinking about embarking on a 'project'? Claire Spreadbury reveals everything you need to know first

STARTING a building project feels exciting. You're creating a new section of your home, designed uniquely for you, which is pretty special. But take heed of the following...

Builders: The people who are going to take on your work need thoroughly researching. They'll all have different work ethics, set-ups and costs. Ask around and find out if friends and family would recommend builders they used - it's surprising how many won't.

Contract: Once you've made a deal with a builder and the work's secured, insist on a contract. This should tell you exactly what will be done when - week by week - and how much you need to pay at every stage. Remember to only pay that money when work's completed as agreed.

Dirt: Strap in for a few months of filth. There will be dust everywhere. Some builders are better than others when it comes to protecting you from the dirt.

Extras: Beware - everything will have been priced up for you, but as the build progresses, there will be lots of additional opportunities for you to haemorrhage cash. The builders' costs, for example, might include uber-cheap, ugly new radiators, but no doubt there'll be an option to upgrade to much prettier ones, for a price of course.

Frayed nerves: Going through a build is incredibly stressful, and you might well need to take on the role of project manager, which is almost impossible if you're trying to work and sort out your family at the same time. Be prepared for difficult conversations with the builders too - if you're not happy with something, it won't change unless you speak up.

Itemisation: When the builder gives you your contract, go through it with a fine-tooth comb to check if anything's missing. If you're ordering a new kitchen or bathroom, check the itemised list. You may have spent days in the shop talking through it all and working out what you want with the supplier, but that doesn't mean they won't incorrectly order something.

Keys: Your builders are likely to need their own set of keys, so be prepared to get a set cut, and to trust them in your home. Otherwise you'll need to remain in the house the whole time, and might just drive yourself insane.

Never-ending: The builders might tell you eight weeks, you'll estimate 12, but when they're still at it during week 14, you might feel like you want to explode. Building work takes an awfully long time.

Portaloo: They're not pretty but if having a portaloo stops dusty builders traipsing up your stairs to use your bathroom, you want to have one installed.

Skips: When you're having building work done, a skip is one of the first arrivals. Don't get too excited about using it to chuck out some big old bits of rubbish you've been hoarding for the last 17 years, though. Generally, builders might let you pop in the odd thing, but if you take advantage, they'll charge you for the cost of the skip - which is hundreds. Prepare yourself for scavengers too; scrap metal dealers will come and rummage at all hours, and some have better manners than others. Same goes for neighbours looking for matching bricks and tiles, and complete randoms hoping for treasure.

Underground: You might have to wave goodbye to bits of your garden or a beloved rose bush when it's dig up to provide the soak away. The tunnels and pipes are often necessary for plumbing work, but rest assured, the garden will grow back (minus the rose bush).

Wall cracks: When you knock down walls and do extensions, you put the rest of the house under severe pressure. Supports will be put in place to ensure it's safe but you will discover lots of brand new cracks, around windows, across corners and over ceilings. This can be alarming but it happens. Wait for the house to settle (usually at least six months is advised), then fill in the cracks and redecorate.