What is the maximum height you can build a garden room without planning permission?

The rules and regulations regarding planning permission in the UK can be complicated and difficult to understand, which is why many people enlist the help of those who specialise in the subject, such as architects or planning consultants, even this can be a very expensive undertaking indeed. That said, employing an architect or planning consultant can save you money as they know their subject and could help you to avoid the expensive nightmare of having to reapply for planning permission after a refusal.

Permitted Development

Garden rooms in the UK are classed as outbuildings, meaning they will generally fall within the rights of Permitted Development, this means that, providing your proposed construction meets the requirements, you should not need to apply for planning permission. It is also important that you check whether you need to apply for Building Regulations approval for your garden room structure.

Permitted Development applies to the building as it was first built or as it stood on 1st July 1948. This means that any extensions or additions built by yourself or previous owners since this date will need to be taken into account and the total area of extensions, sheds or outbuildings (including your new garden room) must not exceed 50% of the total area of land around your home as it stood in 1948.

Maximum height allowed under Permitted Development

If your proposed garden room is to be built within two metres of your boundary, the maximum height allowed within the rules of Permitted Development is 2.5 metres. Anyone about to undertake such a project will be pleased to know that there are many garden room suppliers who have targeted this area of the market and have designed a range of buildings specifically for those needing a garden room that meets these requirements. When building within two metres of a boundary, always remember to allow enough space for maintenance of your garden room and the boundary wall, hedge or fence. If you decide to plant a living screen between your garden room and a neighbouring property, you should consider the impact of the roots upon your garden room foundation as the shrubs or trees mature, you will also need to bear in mind that some trees planted as hedging can grow rapidly, becoming extremely tall in a very short space of time.  If you have a garden large enough to be able to build more than two metres away from your boundary then Permitted Development allows you to construct a garden room that is single story and less than three metres high, four metres high if you intend having a dual pitched roof, although the eaves must be no higher than 2.5 metres above ground level.

Where Permitted Development does not apply

It is important to note that not all home owners will be allowed to build a garden room under the rights of Permitted Development, so it is crucial that you do your research prior to starting any work or making any purchase.

For instance, Permitted Development does not apply if your home is a listed building. Grade I, Grade II* or Grade II listed buildings are of special historic or architectural interest, they are considered to be of national importance and are legally protected within the planning system, you will be required to apply for listed building consent in order to make any changes to the main building or any buildings within the grounds of the property. Permitted Development also does not apply to flats and maisonettes, it may also not apply if your home was converted into a house in the past and has undergone a change of use. If you are fortunate enough to live on designated land, such as an Area of Outstanding Natural Beauty, a National Park, a World Heritage Site, the Broads or a conservation area then we recommend that you contact your local planning authority for advice regarding Permitted Development. In fact, it is recommended that you always seek advice from your local planning authority or a planning consultant, even if you feel certain that Permitted Development rights apply to your home, as rules and regulations can differ from one area to another.

Other Permitted Development Rules

Other important points to be taken into consideration regarding garden rooms and Permitted Development rights are that your garden room should not be constructed at the front of the house, or at the side of the house if the property lies within a conservation area. You are also not allowed to construct a balcony or veranda and any raised platform or decked areas cannot be higher than 300mm. Your garden room cannot be used for residential purposes without planning permission, this includes using it for regular living and sleeping accommodation. If you intend to use your garden room as an office or a building from which you will run a business then you may need to apply for planning permission, particularly if your business is likely to affect your neighbours where increased traffic, parking or access to their properties is concerned.

Building Regulations

Whether your garden room comes under Permitted Development rights or you are required to apply for planning permission, it is most likely that you will still need to apply for building regulations approval. Building regulations are the minimum standard for the design and construction of buildings and they were introduced by the Government to protect our health, safety and well-being. Building regulations cover renovations, additions and alterations to buildings and they also aim to protect the environment. Building regulations approval will be required if a garden room is to have sleeping accommodation, if it is larger than 30m², if it is constructed of non-sustainable, combustible materials or if it is positioned less than a metre from a boundary. Generally, a garden room with an internal floor area of less than 15m² should not require building regulations approval, however, this should always be confirmed with your local authority.

Whether you need advice regarding Permitted Development, planning permission or building regulations, always make time to seek advice from your local planning authority or a planning consultant before commencing work or making a purchase.

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