Can you assess an extension before buying a property?

You can investigate a development idea before buying, but an attractive sketch or neighbouring extension is only a starting point.

Define one scenario.

Describe the space you want, its approximate location and intended use. Gather the listing, floor plans, photographs and any existing planning references. Mark dimensions that are approximate rather than measured.

Check what could constrain it.

The relevant planning regime, designations, previous alterations and site circumstances may affect the route. Your solicitor may need to consider ownership, title and other legal matters; structural and ground conditions require the appropriate technical input.

Connect feasibility with a budget.

Include more than the added floor area. Consider the changes needed to the existing house, services, access, finishes and the practical effects of working around an occupied building. Label unknowns so a desktop estimate is not mistaken for a firm price.

Decide what must be resolved before commitment.

Set out the evidence you have, material assumptions and the next checks. A combined property report can help organise the planning, initial feasibility, indicative costs and value implications of one scenario. It cannot guarantee consent, structural suitability or a future sale price.

England planning background: GOV.UK planning guidance. The applicable rules and processes must be checked for the property’s UK nation and local authority.

General information, not project-specific technical, legal, investment or planning advice. Check the applicable location, documents and circumstances. This guide does not diagnose defects or guarantee costs, value or permission.