Compulsory purchase is the process that a public authority (such as the council or a central Government department) can use to take land from the owner. The owner is paid, but cannot refuse to sell. It can be used for:

• big building projects, such as airport expansions, housing developments or flood defence works
• improving services, such as erecting electric pylons, water or gas pipe schemes or road widening
• clearing areas of bad housing.

Compensation is paid to the owners in the form of money and/or in other ways. For example, you may agree to 'accommodation works', to protect the value of your land, such as a new wall to screen a new road.

If a compulsory purchase order is made, it doesn't necessarily mean that you'll lose your home. But your home may be at risk, so it is important to get advice as soon as possible. If you want to get compensation or to oppose the order, you will probably need to employ a chartered surveyor. In the first instance, you could contact:

• Planning Aid
• the Royal Institution of Chartered Surveyors (RICS) compulsory purchase helpline
• Citizens Advice.

If you rent your home, make sure your landlord is told as well, even if you are happy to move out.

Planning permission is always needed if you want to:

• do building works (eg build, demolish or extend), or
• change the use of the land (eg from a home to a business, or vice versa).

You don't always need planning permission, but you should always check this before any work on your home begins. Usually, your architect or builder will help you apply for planning permission. But if you are doing work yourself, ask the council's planning/ and building regulations departments to explain what you need to do.

Once you have applied, your neighbours will be informed of what you are planning. They will have the opportunity to object if they are not happy about it. Talking to them about it before you apply, and asking whether they have any concerns could help to avoid delays and disagreements. It could also avoid you having to make a second application if they want the plans amended.

Failing to get planning permission can be very expensive. If you carry out the work without it, the council may send you an enforcement notice. If this happens, you can still apply for planning permission late, but if you are turned down the council can insist that you put things back the way they were, and you could also be fined.

Make sure you have all the necessary permissions before work starts. Ask your architect or the council what permissions are needed. If you have a lease, your architect or solicitor can check exactly what it says. If you are a tenant and your landlord is planning an extension, s/he will be responsible for getting all the necessary permissions. Apart from planning permission, the other permissions that you may need include:

• building consent, for almost any structural work
• the freeholder's permission, if you own a flat or maisonette
• the landlord's permission, if you rent. If your tenancy is a short-term one, your landlord may refuse and will usually not pay for the work you have done. But it may be worth getting permission if your tenancy is a long-term one, like a secure council tenancy, or where the work is paid for by a grant (for adaptations for a disabled person, for example)
• permission from neighbours, especially if you live on a modern estate - check your title documents for a 'commonhold agreement' or 'estate agreement'
• if the work includes a party wall (a wall between you and a neighbour's property) you will need a party wall agreement with the neighbour. Ask your architect or contact the Royal Institution of Chartered Surveyors (RICS)
• trees may have preservation orders on them, or you may live in a conservation area, in which case you may need council permission before pruning or removing trees.

Although it may seem obvious, it is also essential that you make sure that your extension is built within the boundaries of your property. Extending beyond the boundary into your neighbours' land could cause you sorts of difficulties, not just with your neighbour, but also if you decide to sell your house in the future. This includes building into roof spaces or over flat roofs if you own a flat: don't build outside the area your lease applies to. If possible, discuss the build with your neighbours to be certain that you are agreed on where the boundaries are. If you disagree on this, get advice.

If you don't have all the right permissions you might have to demolish and rebuild your extension, so it's really important to make sure everything is sorted out before the work starts.

There will be fees to pay for all of these permissions so make sure you budget for them, and try to apply only when you are sure what you want to do - you don't want to have to pay twice. If you want to build beyond what you currently own (eg if you want to convert the roof space above your flat) you may have to buy the extra space (eg from the freeholder). But if you apply before work starts, you should be offered a reasonable price if you leave it until the work is finished, you could pay through the nose.

When a neighbouring property owner wants planning permission, s/he usually has to let you know. You will get a letter that tells you what is going on, and what you can do if you are not happy about it. You will have a chance to write to the council to say what you think.

Before objecting, think about what you are doing. For example:

• Do you need to object, or would it be better to speak to your neighbour first? If you are worried about privacy or light, perhaps your concerns can be dealt with by small design changes rather than doing something that could damage your relationship with your neighbour.
• Do you understand the planning application? Have you seen the drawings and learnt about the details? Ask your neighbour for more details or go to the council's planning department.
• Try to put personal factors out of your mind. How you feel about your neighbour isn't relevant.

If you decide to object, be clear and concise. Leave out personal criticisms and irrelevant information. It can be difficult to understand what reasons will be taken into account. You may be able to get some help from the council's planning department, or by getting an architect or surveyor's advice (which you'll probably have to pay for). But if these options are not available, simply make the points that seem relevant to you, concentrating on what is proposed and the effect it will have on the area and on neighbouring properties.

If your neighbour doesn't have planning permission or one of the other permissions or consents needed before starting, you could report building work to the council or whoever it is who should have been asked. You should report the work if there is a risk of serious property damage or injury. But don't report minor things out of malice. If you are concerned about your neighbour's reaction, ask for your report to be dealt with in confidence.

Some projects are too big for you on your own to do anything about them, eg an airport extension, a new road, a stadium, hospital or prison. Realistically, no one is going to change the plans to suit you. But campaign groups have been successful in opposing large building projects, for example by:

• getting improvements to the final project
• getting improvements in the way the project is carried out, to preserve wildlife or historical remains
• re-siting, cancellation or postponement of the project.

If you have concerns about a major building project that has been proposed for your area, get in touch with a local or national pressure group that can help you. Look on the internet, ask at your local library or contact a local councillor, and see what pressure groups are involved with the relevant issue.

Building work is usually noisy and dirty. The number of people involved can lead to misunderstandings about what can be built where, and in some cases those involved are willing to flout neighbour's rights and the law to get the job done.

Before work begins:

• Choose reputable builders. Use a personal recommendation, if possible, or ask to speak to previous customers.
• Agree what needs to be done and at what price. The builders should give you a written quote, and on big projects there should be a contract.
• Think about having a project manager on a big project. This may be your architect, or another person who keeps an eye on progress.
• Work out who is in charge of the build, and get a contact number for when s/he is off-site.
• Ask how long the work will take, and what kind of upheaval you might face
• Make sure you have enough money to see the project through, and budget for unexpected extras. Ask your architect to tell you how much to set aside.
• Warn neighbours.
• Make sure you have necessary permissions and consents (see above).

While work is going on:

• Discuss progress with the builders. Make sure that you are happy with what is being done, and how long it is taking. Errors are usually cheaper to put right if spotted early.
• Make agreed payments to the builders. Nothing will damage your relationship with builders more than late payment or non-payment. If you are unhappy with the work and want to hold back money, only hold back what is fair. Get advice from your architect or a solicitor, and explain to the builders what is going on.
• If there are problems, keep calm and organised. Don't do anything that puts you or your family at risk. Keep records and report incidents to the person in charge of the builders or to your architect. If you need advice, contact Citizens Advice or a law centre or solicitor.
• Deal with any complaints from your neighbours effectively and politely. Try to listen to both sides of any dispute.
• If one or more workers are behaving badly, be prepared to ask your builder to replace them. If things get heated, you can ask the workers to leave for a while (eg a few hours). But think first, because someone will have to pay for the wasted time, and it might be you.

Most disputes can be resolved by negotiation with the builder. If you have an architect or project manager, s/he should help with this. If there is a dispute about a relatively small matter, you can agree to sort it out at the end of the project. But if there is a serious dispute, you will probably need advice.

There are alternatives to going to court, but sometimes taking court action will be the only way to resolve the problem.

Your landlord or freeholder may need to carry out repairs, or may want to carry out improvements that you agree to. But you don't necessarily have to agree to proposed improvements. Make sure that any damage to decoration will be put right once the repairs have been completed.

If you agree to building work, your landlord or freeholder should tell you what will happen and when, and warn you about any upheaval you can expect. If your landlord wants you to move out while the building work is done, they should provide alternative accommodation at no additional cost. This is not usually the case if you own your home - for example if you are a leaseholder.

Get advice if you are not happy with the works being proposed or the arrangements while the work will be done. Use our directory to find a local advice centre.

You can expect the builders to be considerate, to warn you in advance of any inconvenience like turning off the power or water, and to respond to your reasonable requests about noise etc. But building work is noisy and dirty, and to some extent that is inevitable.

Your landlord or freeholder, or the architect or project manager, are responsible for overseeing the building work. Don't interfere, but if you have a problem with what is being done, report your concerns to the landlord or freeholder as soon as possible. Errors are usually cheaper to put right if spotted early. If the landlord or freeholder doesn't put things right, make sure that you confirm your concern in writing.

If you have a problem with the behaviour of one or more of the building workers:

• Minor problems can usually be sorted out with the foreman or site manager, but if they are repeated or if the builders ignore your complaints, you should tell your landlord or freeholder.
• Builders should not make unreasonable noise. As with all aspects of building work, some noise is inevitable but you should not have to put up with loud music, unnecessary shouting or truck engines left running. The council's environmental health department may be able to help.
• If the problem persists, or if it is serious, it may constitute antisocial behaviour.
• If your decorations or belongings are accidentally damaged, you are more likely to have a claim against the builder than against your landlord. If the damage is to decorations, the builders may be willing to do repairs. But if not, you may have a right to compensation. If repairs are not possible or the work involved would cost a lot of money, get advice.
• If your landlord is allowing builders to behave badly in a way that may force you to leave your home, this may be classed as harassment.

You can't usually stop your neighbour having building work done. If your neighbour hasn't got all of the right permissions and consents, you may be able to stop the work or at least delay it until the consents have been given. But if you have other concerns, it is usually better to raise these with your neighbour.

These are some common problems:

Building on your property

Your neighbour's builders start building on property that belongs to you, across your boundary, or blocking a right of way. Tell your neighbour - first by speaking to her or him and then in writing. You can tell the builders, but always tell your neighbour too. If an error has been made, it should be put right. If you are right about what is yours, you can get your neighbour to pull the new work down and to replace what was there before. But if your neighbour doesn't admit to making a mistake, you have a boundary dispute. You may need to act quickly to protect your rights.

Building or demolishing a party wall

A party wall is a wall between neighbouring properties, including foundations. If your neighbour wants to do work on a party wall, there must first be a party wall agreement or award. If your neighbour starts work without an agreement, you can appoint a party wall surveyor to sort things out - at your neighbour's expense. For more information, contact the Royal Institution of Chartered Surveyors (RICS).

Access across your property

Your neighbour is probably entitled to come into your property, (eg go into your garden or onto your roof), to do work on her/his property. Your neighbour has to ask your permission first. If you refuse, your neighbour can go to court for an 'access order'. The order may make your neighbour or the builders to protect your property, or put right damage, or pay you compensation. If your neighbour is doing only minor repairs, eg repairing a fence, you should probably just allow access. But if major work is required on your property, or if there is a history of trouble with your neighbour, get advice about an access order from a solicitor or Citizens Advice.

Damage to your property or belongings

You are more likely to have a claim against the builder than against your neighbour. If the damage is to property, the builders may be willing to do repairs. But if not, you may have a right to compensation. If repairs will cost a lot of money, get advice from a solicitor or Citizens Advice.

Damage or intrusions to rented property

If the building work affects you, see the above points. But if you have a short-term tenancy, you may not be too worried about building across a boundary or damage to the property. Always tell your landlord what is going on though, so you won't get the blame if damage is found later.

Builders behaving badly

Minor problems can usually be sorted out with the foreman or site manager, but if they are repeated or if the builders ignore your complaints, you should tell your neighbour. If the problem persists, or if it is serious, it may amount to antisocial behaviour.