Philippa’s choice: SIDE-RETURN EXTENSION

Love Philippa’s side-return extension, but unsure about planning permission? Here’s what you need to know

Side-return extensions are a tried-and-tested way of reworking little-used outdoor space to create a bigger, more light-filled kitchen. Even just a couple of metres can make a big difference to the layout.

Do I need planning permission?

Since permitted development (PD) allows a single-storey structure up to 4m high, with a width of up to half the original house, many side-return extensions won’t require planning permission. However, if the extension is within 2m of the boundary, the eaves height will need to be under 3m. Even if PD does apply, it’s sensible to apply for a Lawful Development Certificate.

Are there exceptions?

If you live in a flat, conservation area, national park or area of outstanding natural beauty, you’ll definitely need planning permission. You should also check if your local authority has made an article 4 direction, which limits the scope of permitted development in specific areas.

Can it be two storeys?

You’ll normally need planning permission for this. Most local authorities will want to maintain a gap of at least 1m between properties at first-floor level, and your design shouldn’t impact negatively on your neighbour in terms of light and overshadowing. If side space is tight and too close to your neighbour, a wrap around single-storey side and rear extension may be a better option.

Can I build up to my neighbour’s wall?

If you’re creating a new shared boundary wall or excavating within 3m of your neighbour’s house, you’ll need to send them a Party Wall Notice. This should be obtained two months before work starts. If they give written consent within 14 days, you won’t need to pay for a full party wall agreement.

How much will it cost?

Expect to pay from £1,200 to £1,500sq m, although this can be 15-20% higher in London. You can save money by using large picture windows and a simple glazed door rather than bifolds.