Builders Information

Before starting work

Having decided that you don’t want to move to gain extra space – and regardless of whether you’re extending outward, downward or upward – you’ll always need to get any necessary planning permission and building regulations approval before starting work.

The law relating to ‘permitted developments’ – ie extensions that don’t need planning permission – varies according to:

• property type, eg detached, semi-detached

• the nature of the proposed development*, ie:

• loft or basement conversion, which often don’t need planning permission, unless there’s also a change of use, eg cellar to garage
• outward extension

• height and width of any new part of your home

• which part of the UK you live; each area has its own rules and their respective planning portals have a wealth of information that you can access using these links:

• England
• Northern Ireland
• Scotland
• Wales

* If you home is a listed building or in a conversation area, planning permission and building regulations approval will be needed.

NB Receipt of any necessary planning permission is not the same as ensuring that your work complies with buildings regulations, or vice versa; the two matters are entirely separate and each must be addressed in its own right.

It also makes sense to talk to your neighbours as soon as possible in case your proposals will adversely affect them, eg by overlooking their garden or blocking out light. Discussing such concerns early on will make life much easier, especially if planning permission is required, in which case the local council’s planning team will make them aware of your intentions anyway.

In addition, you should check your title deeds to make sure there aren’t any restrictive covenants that would prevent the work from going ahead. If in any doubt, contact a suitably qualified solicitor.

And it’s important to bring your development to the attention of your mortgage lender and household insurer in case it affects the nature of their interest in your property or their business terms with you.

Extending outwards

If you have enough room in your garden, an outwards extension of one or more storeys can substantially increase the size and value of your home.

This could work out cheaper than moving to a larger property because building an extension will avoid certain ‘hidden costs’, such as fees for an estate agent, legal work, stamp duty land tax and removal services.

Extending upwards

Did you know that as much as 30% of your home’s total floor area is taken up by loft (also known as ‘attic’) space? It is often unused or under-used as a storage area, making it ideal for redevelopment.

Because the building’s main structure is already there, a loft conversion will be cheaper than extending outwards. Figures suggest that creating an extra bedroom with an en suite bathroom or a hobby room, for example, could increase the value of your property by up to 20%.

There are a few things you should check before consulting an architect to discuss and plan your loft conversion:

• that it’s free-from wet or dry rot; if not, these problems will need to be cured

• its size – if there are three metres between the main purlins (the horizontal beams that support the rafters) on each side of the roof, this should be enough; a smaller gap may be enough to allow some kind of conversion

• your roof’s construction – trussed rafters, ie factory-made lightweight triangles that support the roof, will make a conversion more difficult

• that it’s free from bats – check for droppings; bats and their roosts are protected by law so, before staring work, you must get appropriate advice*.

*Countryside Council for Wales
  Natural England
  Northern Ireland Environment Agency
  Scottish National Heritage

Extending downwards

If you already have a cellar, a basement conversion should be fairly straightforward, as will be the case for older homes with suspended timber floors. It’s also possible to create a new basement in a modern property, although this is likely to be more complex and expensive.

This type of extension could add an extra 20% and 30% to the value of your house.

Adequate, professionally installed, waterproofing, heating* and ventilation are vital to any basement conversion.

* only Gas Safe Register engineers should carry out gas-related work

And regardless of whether your conversion needs planning permission, it must comply with many building regulations, including:

• damp proofing
• electrical wiring
• fire escape routes
• ventilation
• water supplies.

You will also have to consider the Party Wall Act 1996, which relates to work on:

• any party wall
• excavations:
• within three metres of a neighbour's property
• to a depth greater than the bottom of your neighbour's foundations.

You are legally obliged to inform your neighbours of your plans with a Party Wall Notice or a Party Structure Notice, depending on the nature of the work and which is usually prepared by a suitably qualified surveyor, who will also guide you through the next steps.
Things could be brought to a halt if your neighbours are unhappy with your proposals, so it’s sensible to talk to them as soon as possible.