Building an extension, annex and conservatory are among the top five home improvement projects for this year, but before people steam ahead with grand extension plans, they need to make sure they understand the rules to avoid upsetting the neighbours or winding up out of pocket.
Tom Edwards, partner in property disputes at LCF Law, said: "Homeowners must be cautious about getting into boundary and party wall disputes. It can affect the sale of their property and its value.
"Some homeowners think they are entitled to build on their land without considering neighbouring properties simply because it's their land, or they think it. - But they don't appreciate the traps they can fall into which can irretrievably break down relations between neighbours and could end up costing them thousands of pounds.
Each case is different, and the costs depend on a wide and varied number of factors, but it could cost tens of thousands of pounds.
Know your boundaries
Overstepping or misinterpreting property boundaries is a common cause of disputes says Tom.
"A family came to me for help because their neighbour, who had just finished building an extension across their own driveway, thought they were entitled to use my client's driveway to get around the back of their house. The neighbour had looked at the title plans which seemed to show they owned some of my client's drive even though it had been fenced off since the properties were built over 20 years earlier.
"Instead of talking things through, they removed the fence while my client was at work, partially took my client's drive to use as a walkway and their child started using the area on which to ride their bike."
Title plans can be misleading. A red line on the plan indicates where your general boundary lies not its precise location.
Tearing up fences to make way for your extension because you believe you own the land could cause a legal dispute.
To avoid this, you can apply to Land Registry who will send a surveyor to your property to have your boundary determined. The Land Registry will provide a cost for this.
"Alternatively, you can sign an agreement with your neighbour describing where the boundary is," said Tom. "Or you can play detective and review the original title deeds for your property, which in some cases could be 200 years old. This can be very complicated so it's best to seek advice from a specialist surveyor or solicitor to save you expense and stress in the future."
Party Wall Act Notice
The Party Wall Act 1996 is a piece of legislation designed to prevent and resolve disputes between neighbours over building or digging work that affects a party wall. A party wall is a wall shared between you and your neighbours common in semi-detached homes, terraces and homes. However, your extension could fall under Party Wall rules.
Tom said: "If you want to start building work within six metres of an adjoining owner's home you need to be conscious that by digging foundations you may fall within the Party Wall Act, which means you must serve written notice to your neighbour of your plans."
A Party Wall notice must include the names of the owners planning the work, details of the construction, when it will start and be signed and dated. RICS has produced a guide for homeowners on Party Wall regulations. Your neighbours could take legal action if you don't serve notice.
Overhanging roof and guttering
If you build your extension right up to the boundary of your property, even if the outside wall does not encroach on your neighbour's land, the overhanging roof or guttering might. This is known as trespassing. Your neighbours could take you to court to force you to remove the trespass, which may mean you have to redesign or demolish your extension.
If your extension has not been built according to your planning permission and your neighbour complains to the council, you could be issued with an enforcement notice telling you to demolish your extension to comply.
Respect your neighbour's rights
Before you build your extension, check if any neighbours have rights over the land, you own such as a right of way.
"Let's say there's a footpath between two properties," explained Tom. "The owner of that path might decide to extend their property on to it but by doing so they may be denying someone their right of way. This could be unlawful, and an injunction could be taken out against you to take down your extension."
Your neighbour's right to light is another factor to consider, adds Tom. This means they have the right to benefit from natural light, not sunlight.
Homeowners can find out which rights come with their property by reading their title deeds.
"Your title deeds might say a neighbour can't build more than two stories up, for example, to protect your natural light," said Tom. "Owners can also acquire rights to light over time. If you've had the benefit of natural light to your property for 20 years or more, even if it's not in your deeds, it can become your legal right."
If your extension is blocking out next door's natural light your neighbours could make a legal claim against you. RICS' consumer guide on Right to Light explains when your neighbours can make a claim.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.