Whether you want to build up, out, or in the garden, you can extend your home by taking advantage of the latest permitted development rights.

5 easy ways to extend your home

When extending your home, the prospect of navigating the planning process can be daunting enough to deter even experienced self-builders. However, the great news is that there are a number of projects that can be completed without applying for permission, saving you time, money and hassle.

In short, permitted development (PD) allows you to extend your home without requiring full planning permission, providing you adhere to certain guidelines relating to the size and appearance of your new addition.

What’s more, if you’re looking to convert your loft as well as build a ground-floor extension, it’s possible to complete some of the work under PD (the loft, for example) and apply for permission for the remainder of the project. A good designer will be able to advise the best route to take, to make the most of PD allowances.

In some areas (classed as designated land), such as conservation areas, national parks, Areas of Outstanding Natural Beauty and world heritage sites, PD rights can be removed, so it’s always best to check with your local planning authority if these allowances apply. Regulations also differ between England, Wales, Scotland and Northern Ireland. Do bear in mind that any new extension, even when done under PD, will still have to meet building regulations.


What can you build?

Side-return Extension: Create valuable extra living space by incorporating the redundant strip of land to the side of the house (often seen in period terraces). It’s the ideal way to create a larger kitchen; by removing the original exterior wall you can create a space that stretches across the full width of the house to the adjoining boundary.

Rear Extension: Recent changes to PD guidelines in England mean that in most areas (not on designated land) you can now add a single-storey rear extension up to eight metres from the original rear wall of a detached house (previously it was four metres), or six metres from all other houses, such as semi-detached or terraced properties (previously three metres). This allows you far greater scope to create a large, open-plan space that connects to your garden. Since this is a temporary change to the regulations, any extensions built under permitted development must be completed by 30 May 2019.

Double-height Addition: Two-storey rear extensions are also possible (not on designated land), although anything you build must not extend beyond the back wall of the original house by more than three metres or be within seven metres of any boundary opposite the rear wall.

Loft Conversion: To fall under PD rights, repurposed attic space must not exceed 40 cubic metres for terraced houses or 50 cubic metres for detached and semi-detached houses. This still provides plenty of scope for the creation of one or more dormers to make space for a large master bedroom and en suite, or even two smaller bedrooms and a bathroom.

Garden Room: You can construct many different styles of outbuildings, which you could use as a separate garden office, a home gym or perhaps an additional living room. Any new structure must be single storey and not exceed 50 per cent of the land surrounding the original house – any existing sheds or outbuildings are also included within this total.

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Style and Look

Under existing permitted development rules, any materials used for the exterior of an extension need to be of a similar appearance to those of the original house (this doesn’t apply to conservatories), so if you want to have a cedar-clad loft dormer, for example, you’ll probably need to submit a full planning application. This doesn’t mean, however, that you can’t be adventurous with the overall appearance of your extension – a brick-built addition or rendered design that matches the original house can be combined with frameless rooflights and full-height sliding, pivot or bi-folding doors to create a modern look.


What next?

If your extension falls under the standard guidelines for PD you won’t need to submit a formal application for planning permission, although it’s always advisable to check with your local authority that you do meet the PD criteria before commencing any work. It’s also a good idea to apply for a Lawful Development Certificate, which provides proof that the work was permitted. If you decide to sell your property in the future, this is something potential buyers will demand to see as evidence that your extension or loft conversion was done legally. To take advantage of the temporary extension to PD rights, however, you will need what is called prior approval before starting your project, which means going through the neighbour consultation scheme – see page 131 for further details.

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In Focus: Permitted Development

  • In planning, the term original house means the property as it was first built or as it stood on 1 July 1948.
  • Extensions (including previous ones) and other buildings must not exceed 50 per cent of the total area of land around the original house.
  • Side extensions can be only single storey and no more than half the width of the original house.
  • Any single-storey extension should be no higher than four metres; and within two metres of a boundary, no greater than three metres.
  • The maximum eaves and ridge height of a two storey extension can be no more than the existing house, and not more than three metres if it falls within two metres of a boundary.
  • The eaves and ridge of any extension must be lower than the existing house.

Words: Beth Murton, Photography: Gavin Fraser; Monica Jackiewicz/Fine House Studio; Tim Crocker; Jake Fitzjones; Heather Hobhouse; Gianluca Maver

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