A garden outbuilding is a cost-effective and relatively quick way to add some more space to your home. Whether you are looking to build a stylish new office space, a cinema, or children’s playroom, an outbuilding could be a great option if you have the garden space.
How long does a garden outbuilding take to build?
Outbuildings can either be custom-designed or come as part of a modular package, and timelines vary significantly between each option.
Modular outbuildings are mostly constructed off-site, and so can be put up within a few weeks or less depending on the size of the project. Meanwhile, professional custom-designed outbuildings are unique and designed and built to measure, so can take two months or more to construct.
How much does a garden outbuilding cost?
Similar to how the construction timelines vary between modular and custom-designed outbuildings, pricing varies in a similar way.
Modular outbuildings are produced en masse in factories off-site and so you have less choice in terms of materials and finishes, but they are cheaper to build. Smaller modular outbuildings generally start around 20,000 and go up from there depending on your choices.
Bespoke, custom-designed outbuildings offer you the chance to make the exact garden room of your dreams, where you can choose every detail from choice of roofing material to window fittings, but such unique builds come with additional costs. Bespoke garden outbuildings normally start at around £1,000 per square metre but can be significantly more.
Do you need planning permission for a garden outbuilding?
In general, building an extra room in the garden will be classed as an outbuilding and constructing such rooms is considered a “permitted development right” if it complies with the following rules:
- It is a single-story building with a maximum overall height of 4m for a dual-pitched roof or 3m for any other roof and eaves below a maximum height of 2.5m.
- It has a maximum height of 2.5m within two metres of the boundary of the garden or house.
- It has no verandas, balconies, or raised platforms.
- It covers no more than half the area of the land around the “original house”
- It is not built on land forward of a wall forming the principal elevation (ie. It cannot be in a front garden).
However, not all properties have “permitted development rights”. Flats, maisonettes, converted houses, listed buildings, homes in conservation areas, and some new build homes do not come with such rights. It is therefore always best to check with an expert, such as by contacting Good London Builders, if you are unsure about whether your proposed outbuilding will need planning permission.
For what purposes can I use my outbuilding?
The general rule is that an outbuilding must serve the main house and not be independent from it. This means that you can use the outbuilding as an office, cinema, workshop, or children’s playroom, and if someone sleeps on the sofa in there every now and again it is unlikely to be a problem.
You cannot, however, use the outbuilding as an extra bedroom, bathroom, or kitchen, and it cannot be any other form of self-contained accommodation, such as a “granny annexe” without building regulations approval.
Do I need building regulations approval?
Small, detached outbuildings that are less than 15 square metres in size and built to be offices, playrooms, or similar will generally not require building regulations approval. However, larger constructions or those that include any sleeping space will require approval.
As with other regulations, it is always useful to get a professional opinion on whether you may need building regulation approvals before you begin any project. Planning and building regulations are complex, and it is often useful to have an expert guide you through the process from start to finish.
Should I get a Lawful Development Certificate (LDC)?
The rules around what is and what is not an outbuilding are often a little unclear and so even if you think your garden room would be considered a permitted development under current planning rules, it may be useful to obtain a lawful development certificate for piece of mind and the avoidance of any doubt.
An expert from Good London Builders can help you with the application process and this documentation will prove that your planned construction is permitted both to the local authority and any future buyers of your property.