If your two-storey side extension has been refused, most often for creating a ‘terracing effect’, you have the right to appeal, and these are among the winnable types of appeals. Our chartered town planners handle the whole appeal for a fixed fee of £399.
Why two-storey side extensions get refused
Planners are wary of two-storey side extensions because, unlike most single-storey work, they can’t be built under permitted development and they change how a house looks from the street. The objection you will see most often is the ‘terracing effect’: the complaint that by extending out towards the boundary you have closed the gap between your house and next door, so a pair of semi-detached houses starts to read as a continuous terrace. Refusals also commonly cite the lack of a set-back at first-floor level, or an extension so wide it stops looking subordinate to the original house.
Why these appeals succeed
The terracing effect is a good example of an objection that sounds firm but often isn’t. Planning policy does not ban it. The test is not whether your extension creates a terracing effect, but whether that effect causes real harm to the street. On a road where the houses are already a mix of types, or where neighbours have made similar extensions, closing one more gap changes very little, and inspectors regularly grant permission. That is exactly what happened with our two-storey side extension appeal in Kingston, where the council objected to the loss of a gap that most of the street had already built over. It’s a favourite of the stricter councils, too: we’ve won the same argument against Barking & Dagenham, the council that refuses more planning applications than any in England.
Design and context do the rest. A first floor set back from the boundary, a set-back from the front wall, or a roof that keeps the extension subordinate can all preserve a sense of separation even where the ground floor reaches the boundary. And where the council has simply applied its design guide rigidly, insisting on a one-metre set-back that would look odd on your particular street, that rigidity is itself grounds for appeal.
What the appeal process involves
Since April 2026, householder appeals follow the Part 1 written procedure: no long statement, just your application documents, the council’s reasons for refusal and a concise 250-word summary. Because nothing new can be added later, the evidence that wins a terracing case, meaning photographs of the other extended houses on your street, the pattern of gaps, and the set-back and width of your own design, needs to be in the application from the start. Our guides explain how the appeal system works and how the 250-word summary is written.
Deadlines and cost
You have 12 weeks from the date on the 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 the decision.
Get free initial advice
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.