If your garden room, home office, gym or granny annexe has been refused planning permission, you have the right to appeal. Outbuilding refusals are often based on the case officer’s suspicion on what you intend to use it for, rather than any real expectation of harm. Our chartered town planners handle the whole appeal for a fixed fee of £399.
Why outbuildings get refused
Permitted development rights for outbuildings are relatively generous, and most garden buildings can be built without any application at all. Problems arise when full planning permission is needed — because the property is a flat, sits in a conservation area, or has had its permitted development rights removed by condition.
At that point a particular suspicion takes over. Planners worry that what is described as a home office or gym is really an attempt to create a separate unit of accommodation at the bottom of the garden — the familiar fear of ‘beds in sheds’. That concern shapes the whole assessment, even where nothing about your proposal justifies it.
Councils generally expect outbuildings to be clearly domestic in scale and subordinate to the main house, sited to the side or rear, single-storey, and low in overall height. Buildings that compete visually with the house, or look capable of independent occupation, are far more likely to be refused.
Granny annexes are harder still
Annexes attract more resistance than ordinary outbuildings, because councils fear that accommodation intended for a family member will later be let out as a separate dwelling — in effect a new house in the garden of an existing one.
Permission is easier to obtain where the accommodation is not fully self-contained. An annexe without a kitchen, whose occupant relies on the main house for meals, is much less likely to be treated as an independent dwelling. Some councils will accept a fully self-contained annexe but impose a condition restricting its occupation to members of the main household — a condition worth understanding, because breaching it later can trigger enforcement action.
What wins these appeals
The strongest arguments are usually these. First, the design answers the suspicion: modest scale, single storey, tucked at the end of the garden, clearly ancillary to the house. Detailed floor plans showing the intended use — office, gym, hobby room — do real work here, because they make the ancillary purpose concrete rather than asserted.
Second, context. Where similar outbuildings already exist nearby, your proposal sits within an established pattern of development rather than introducing something new. And where the council has recently approved something comparable a few doors away, inconsistency becomes a powerful argument — that is precisely how we won a garden annexe appeal in Lincoln, where the council could not explain why two near-identical proposals deserved opposite decisions.
Third, testing the reasoning. If the refusal cites the character and appearance of the area, that is a judgement, not a measurement, and it can be challenged on the evidence of your own street.
What the appeal process involves
Since April 2026, householder appeals follow the Part 1 expedited written representations procedure: no lengthy appeal statement, just your original application documents, the council’s reasons for refusal, and a concise 250-word summary of why the decision was wrong. Because nothing new can be added later, the plans and supporting information in your application do the heavy lifting — which is why detailed floor plans matter so much in outbuilding cases. See our guides to winning a planning appeal and the 250-word summary.
Deadlines and cost
You have 12 weeks from the date on the council’s decision notice to lodge a householder appeal. The Planning Inspectorate charges no fee; ours is a fixed £399 covering the review, the appeal form, the summary and all liaison through to decision.
Get free initial advice
If your annexe has already been refused because the council says it would be a separate home, see our guide to appealing an annexe refused as a “separate dwelling”.
Send us your refusal notice and we’ll review it free of charge, tell you honestly what we think your chances are, and explain the next steps. Get in touch — we respond within one working day.