What Size Summerhouse can I Build in my Garden?

Many people dream of building a summer house in their garden, but are naturally concerned about planning permission or complaints from neighbours. The good news is that there are simple ways to avoid any problems.

Summer houses and planning consent

The size, location, height and intended use of your summerhouse will determine whether planning permission is required. If it turns out that consent is needed, then your neighbours will be given the chance to raise any objections.

Under Permitted Development rules, you can build a single storey summerhouse, known as an outbuilding for planning purposes, without consent, up to four metres in height if it has a dual-pitched roof, with a maximum eaves height of 2.5 metres. For all other roof types, the maximum height for the summerhouse may not exceed three metres.

If you are planning to site your summer house within two metres of the boundary of your property, then you’ll need to restrict the height to 2.5 metres.

Whatever the height, if you are looking to avoid a planning application, then the summerhouse must not cover more than 50 per cent of the original plot area. An extension is not considered part of an original house, unless it was constructed prior to 1 July 1948. It’s also important not to site the summer house any closer to the original house as it was first constructed, or as it was as of 1 July 1948, whichever is later.

For unlisted properties in Conservation Areas, provided the outbuilding is sited behind the rear wall of your home and falls in line with the height requirements, it would meet the rules. However, for listed properties, planning permission would be needed for any height of outbuilding, as it would for flats and maisonettes. Permitted Development Rights do not always apply to properties that have undergone a change of use, or that have been converted into a residential dwelling.

In 2016, the guidance was updated, so that an outbuilding would only fall under Permitted Development rules if its purpose was incidental to a house. Translated, this means that self-contained usage would not be permitted without permission. So, all good if you are planning to use your summer house as a garden retreat, a hobby or craft room, a gym or a spa, but not so if you wanted to use it exclusively as a bedroom, a bathroom or a kitchen.

This is where the guidance can become a little fuzzy, however. Sometimes, certain features excluded by the guidance could make the summerhouse more enjoyable. For example, a lavatory in an outdoor gym, a fridge and running water in a bar, or a sink in a hobby room. Such fixtures and fittings have been deemed incidental and therefore lawful by planning departments, but these decisions will vary from one local authority to the next.

What are the most common summerhouse sizes?

Providing you remain within the stipulated heights for your summer house, you should not face issues with planning or neighbourly complaints. So what size summerhouse should you choose? This all depends on how you will use it, and the available plot space within your garden.

If you have ample space and have big plans for your garden building, a 20 x 10 feet summer house could be the right choice. If you are seeking something somewhat smaller, there are plenty of options for your summer house. 10 x 6 feet is a popular size, as is 4 x 8. Summer house sizes can also be quoted in metres, and you will find some of the most commonly available as 3m x 3m, 4m x 3m and 5m x 3m.

You can get a good feel for the summer house sizes available by viewing our Malvern Collection summerhouse brochure.

Summer house dreams? Let Surrey Hills Garden Buildings make them a reality.

If you are considering investing in a garden summerhouse, you are welcome to get in touch with our friendly, experienced team. We’ll ensure you know your planning permission responsibilities inside out, so all you need to do is enjoy your new garden room.

Why not visit one of our dedicated show sites for inspiration and advice? We look forward to welcoming you.