What if my drawings don't match my house in London?

Why the council cares about accuracy

The national rules for planning drawings are short but firm. Government guidance says that any plans or drawings must be drawn to an identified scale, and plans must show the direction of north. It also says the application site should be edged clearly with a red line on the location plan.

An officer judges your scheme from what the drawings show: how deep the extension is, how close it comes to the boundary, how tall it is beside the neighbour. If the existing house is drawn wrong, those judgements rest on the wrong picture. Missing items are a separate problem: the same guidance notes that where something required is absent, an application is not valid, and therefore cannot be determined by the council. Our post on what drawings a householder application needs sets out the full list.

If the application is still with the council

Tell the case officer as soon as you find the error. Many councils will accept revised drawings during the application if the change is small and clearly a correction, though they are not obliged to, and a larger change may need to go out to the neighbours again. If the change alters what was applied for, the officer may ask you to withdraw and submit a fresh application with the right drawings.

If the council has flagged the application as invalid because a drawing is missing or wrong, the fix is usually straightforward: supply the drawing it asked for, to scale and correctly labelled. We can prepare corrected sheets that keep your original drawing numbers with a new revision letter, so the officer can see exactly what changed.

If the drawings were approved but are wrong

Once permission is granted, the approved drawings are often listed in a condition of the permission, and the work is expected to follow them. Under the Town and Country Planning Act 1990, failing to comply with any condition or limitation subject to which permission was granted counts as a breach of planning control, in the same way as building without permission.

That does not always mean starting again. For a small change, the council can grant a non-material amendment, and guidance says plainly that there is no statutory definition of 'non-material': it depends on the scheme as a whole. For a bigger change, a section 73 application can be used to make a material amendment by varying or removing conditions, including the one listing the plans. Where the corrected scheme is a different building, a new application is the honest route. Which one applies is the council's call, so we draft the corrected drawings and a short note and let the officer say which route they want.

If it is already built differently

When the finished work does not match the approved plans, the council can treat it as a breach, but guidance says that enforcement action should, however, be proportionate to the breach, and councils should usually avoid formal action over a trivial or technical breach that causes no material harm. That is a judgement only the council can make about your case, and we would not guess it for you.

Time does not quietly fix it either. For building work substantially completed on or after 25 April 2024, the period in which a council can take enforcement action is 10 years, not the old four. If you are in this position, take advice early: a planning consultant or solicitor for the legal side, and accurate as-built drawings from us for any application that follows. We draw what is there; we do not give legal advice.

If the work has stood for years, proving an older extension is lawful explains the certificate route and the evidence it needs.

Taking over drawings someone else started

A half-finished set, a designer who has stopped answering, or drawings that came with a house you bought are all common. You do not need anyone's permission to appoint someone new. We do not edit another firm's files; we survey the house ourselves and draw the scheme fresh from our own measurements, keeping the design you agreed where it still fits the real building. That keeps the drawings ours to stand behind.

If the drawings were refused rather than wrong, our post on who can redraw plans after a refusal covers that case. If you want the house measured without us visiting at every stage, see what can be done without a site visit. For Building Regulations drawings you suspect are wrong, an independent drawing review checks a set before your builder prices it.

What correcting the drawings costs

Correcting a set usually means a fresh measured survey and corrected planning drawings, both at fixed fees agreed before we start: a survey from £200 and planning drawings from £745. If the fix turns into a new householder application, the council fee is due again. Our planning drawings service covers the drawings, the note to the council and the submission. We cannot promise what the council will decide; we can make sure the drawings it decides on show your real house.