A refusal is rarely the end. Before doing anything, read the decision notice and find the numbered reasons for refusal — they are a roadmap, not a verdict. Then work out whether your refusal is a fixable near-miss or a fundamental policy conflict; most householder refusals are the former. You usually have three routes: amend and resubmit, appeal to the Planning Inspectorate (12 weeks for a householder application), or take advice first. The most damaging move in week one is firing off a rushed appeal.

A Lawful Development Certificate (LDC) is a council’s formal confirmation that a project is lawful — either something you plan to build under permitted development (Section 192), or something already built that no longer needs permission (Section 191). It is not planning permission, and it can’t be refused because the council dislikes the design: the only question is the evidence. Homeowners use one for certainty before building, or as clean proof of legality when they come to sell.

If your application was refused you have a right to appeal to the Planning Inspectorate — free of charge, within 12 weeks for a householder decision (six months for most others). But appealing is not always the right move. From April 2026 you generally cannot put new plans or evidence before the inspector, so they judge the same scheme the council refused. If the refusal is something you could design out, a revised resubmission usually beats an appeal. Read your refusal notice first, then choose your route.

Prior approval is a halfway house between permitted development and a full planning application. For certain permitted development rights — larger rear extensions, barn-to-home conversions, shop-to-home changes — you can build without full permission, but only after the council has signed off specific matters (such as the impact on neighbours, flooding or highways) in advance. You apply, the council has a fixed window — usually 56 days, or 42 for a larger home extension — to decide, and on some rights its silence counts as consent.

You need planning permission for a change of use only when the change is “material” — a real change in the character of how a building or piece of land is used. Moving between uses inside the same class — for example a shop to a gym, both Use Class E — is not development and needs no permission. Moving to a different class, or to a sui generis use such as a pub or hot-food takeaway, usually does — unless a permitted development right such as Class MA (commercial to residential) covers it. A full change-of-use application costs £610; a Class MA prior approval costs £260 per home.

An SSSI — a Site of Special Scientific Interest — is land legally protected for its wildlife, geology or landform under the Wildlife and Countryside Act 1981. You can still own, use and often build on or near one, but listed works need Natural England’s consent, and any planning application in or near the site is referred to Natural England. Protected-site status rarely blocks development outright; it raises the evidence bar and the cost of getting it wrong.

The invisible line that decides where your permitted development rights stop — and the one homeowners most often get wrong.

A garden office rarely needs planning permission — until the way you build it, or the way you use it, quietly tips it over the line.

Side extensions follow tighter rules than rear ones — and almost every catch is about the boundary, not the building.