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The content on this page is provided by Resi Design Ltd. and is for general guidance only and should not be relied upon as a substitute for professional advice. Whilst reasonable efforts are made to update the content, neither Rightmove or Resi offers any warranties or guarantees on the accuracy of any information displayed and accepts no liability for any loss, damage, or costs incurred as a result of reliance on such information. Always seek independent, specialist advice before making decisions related to property improvements or renovations.

Data on planning applications, home extensions and build costs is provided by Resi Design Ltd.. Planning data is calculated using the last 2 years of residential applications within the selected planning authority. Home extension data, such as build costs and project timelines, are calculated using approximately 9,000 architectural projects Resi has completed, and 23,500 builders quotes submitted via Resi's platform. Build costs are adjusted according to inflation rates to more accurately represent today's prices.