Outbuildings cost, planning permission and building regulations?
Updated: May 29
What Can You Use an Outbuilding for in the UK?
In the UK, outbuildings are typically used as extra indoor recreational spaces, or as additional space for a home office or workshop. Outbuildings can be used for a variety of different purposes.
Do I need planning permission for an outbuilding?
In most cases, no. As long as you adhere to the guidelines of permitted development and are not located within a conservation area, you do not require planning permission for outbuildings.
Permitted Development Requirements for Outbuildings
Under Permitted Development (PD) rules, you can build multiple outbuildings as long as the total area they cover does not exceed 50% of the total area of the curtilage. When calculating the 50% area, you should include any extensions but not the area covered by the main house.
Outbuildings cannot be positioned forward of the principal elevation of the house.
Outbuildings and garages must be single-story only.
They must have a maximum eaves height of 2.5 metres and a maximum overall height of 4 metres if they have a dual-pitched roof, or 3 metres for any other type of roof.
If the outbuilding is within 2 metres of the boundary, its maximum height must be 2.5 metres.
Verandas, balconies, or raised platforms are not allowed. If a platform is used, it must not exceed a height of 0.3 metres.
In National Parks, the Broads, Areas of Outstanding Natural Beauty, and World Heritage Sites, the maximum area covered by buildings, enclosures, containers, and pools over 20 metres from the house is limited to 10 square metres.
Do I need building regulations for an outbuilding?
Check out our blog on building regulations for outbuildings.
Do I need a party wall surveyor for an outbuilding?
If the outbuilding is on the boundary line, you would need to serve a party wall notice or if you are building a foundation within 3m of a neighbouring structure, then you are required to serve a party wall notice. To avoid this, you can leave a space between the outbuilding and the boundary line and make sure your building is over 3m from a neighbour’s building.
How much does an outbuilding cost?
The cost of an outbuilding depends on several factors, including:
Type of construction
Fees for water and other pipe installations, if required.
Overall, the cost can vary widely depending on these factors.
Type of materials used:
The biggest cost associated with building an outbuilding will be the materials needed for construction. Three main types of materials can be used to make an outbuilding:
Wood/Timber – Usually the cheapest option, but it does not last very long. Wood might not be the best choice if you regularly water your garden. It is commonly used for making shed outbuildings and can cost between £500 to £10,000, depending on the size and complexity.
Concrete - While it may be an expensive option, concrete is extremely durable and long-lasting. Additionally, most concrete is waterproof, making it a safe and secure choice for the long term. The cost for this option can range anywhere from £4,000 to £15,000, depending on various factors.
Brick - Many people choose to build houses out of brick, although this is the most expensive option on this list. It also requires a considerable amount of labour. Brick outbuildings can cost anywhere from £4,500 to £18,000.
Size plays an important role in outbuilding construction. After building materials, the size of the outbuilding is the second biggest factor to consider. The larger the outbuilding, the higher the material and labour costs.
The size of your outbuilding will greatly affect its building cost. For instance, an average garage-sized concrete outbuilding costs around £7,100, including the basic worker's pay wage. However, if you build an excessively large outbuilding, the cost can increase to as much as £90,000.
The cost of labour is not fixed. It varies depending on who you hire to do the work. Factors such as the size of the outbuilding, the design you must have built, the piping installation, and the number of partitions you want can all affect labour costs.