Appeal against a refusal of a Certificate of Lawfulness for a residential outbuilding
The main issue in this appeal was whether the proposed outbuilding was genuinely required for purposes incidental to the enjoyment of the main house.
Residential outbuildings can be permitted development, meaning that planning permission is not normally required. However, permitted development rights only apply where certain conditions are met.
One of the key restrictions is that an outbuilding must be reasonably required for the homeowner’s use and must be used for purposes incidental to the main dwelling. Typical incidental uses include storage, a home office, a home gym or a hobby room. An outbuilding must not function as a separate unit of accommodation.
Councils often refuse Certificates of Lawfulness where they consider an outbuilding to be too large to be regarded as incidental, even where it meets all of the other technical requirements of permitted development.
In this case, the council accepted that the proposal complied with the relevant limitations of Class E, Part 1, Schedule 2 of the General Permitted Development Order 2015 (as amended). The sole issue in dispute was whether the size of the outbuilding was reasonable for its intended uses.
The inspector carefully considered the proposed uses of the building, which included a home office, a gym and a storage area. It was accepted that each of these uses was incidental to the enjoyment of the dwellinghouse. The inspector also considered the size of each room and found that the dimensions were proportionate to their intended functions, including the need for equipment and usable internal space.
On that basis, the inspector concluded that the outbuilding was reasonably required for incidental residential purposes. The appeal was allowed and a Certificate of Lawfulness was issued.
This decision illustrates that the test for incidental use is not based on size alone. What matters is whether the building is genuinely ancillary to the main dwelling and whether its scale is justified by its intended use.
If you are experiencing difficulties obtaining a Certificate of Lawfulness for an outbuilding, particularly where the issue relates to size or incidental use, specialist advice can often help clarify whether an appeal is likely to succeed.
