Types of garden rooms that can be constructed under permitted development without planning
The term garden room encompasses a host of detached garden buildings from swimming
pool enclosures, office or study room, gym room, hobbies room in fact anything you want really provided it can be
classed as an ancillary use.
And there perhaps lies the rub. Many Planning Departments determine any large buildings compared the original
dwelling or plot not to be of an ancillary use. Also, garden rooms containing too many facilities that could form
the basis of an independent dwelling or contain sleeping space usually fall outside of what is considered to be an
However, some garden room suppliers have experienced alternative interpretations from some Local Councils that
permit annexes under Class E of the GPDO. The definition these councils use for determining ancillary use is
whether or not the proposed garden room has a high dependency upon the main dwelling. Therefore, it could be argued
that a garden building containing bedrooms and washing facilities for example but does not have a kitchen still has
a high dependency upon the original dwelling and is therefore of an ancillary use.
Regretfully, most Planning Departments are not that liberal with their thinking and usually jump on any avenue
or excuse to class a detached Class E garden room building as not being ancillary.
The term ancillary is not just restricted to its use. Ancillary can also mean in size and scale of the new
garden room so hence large garden buildings on plots containing small dwellings may not be considered
For a diagram of the restrictions affecting detached garden
rooms click here.