Do I Need a Survey Before Building an Extension?

Extensions and loft conversions often look straightforward on paper, but small site errors can quickly turn into expensive on-site changes. Surveying the existing building and garden before detailed design gives your architect reliable information on levels, structure and boundaries, reducing risk for everyone involved.

What to Look For

• Your proposed extension is close to the boundary or neighbouring buildings
• There are retaining walls, steep level changes or complex garden layouts
• Existing drawings are based on old estate agents’ plans or rough sketches
• You plan to alter roof structure, dormers or chimney positions
• Party wall surveyors have requested accurate existing sections
• Contractors are asking for verified dimensions before pricing

How We Diagnose the Problem

A measured building survey provides accurate floor plans, elevations and sections of the existing property, while a topographical survey captures garden levels, drainage covers and access. Together these give your design team a robust base to work from and avoid dimensional surprises once work starts on site.

How We Fix It

Our survey partners capture the whole property in one visit using total stations and laser scanning where appropriate. Deliverables include CAD files and PDFs that your architect and structural engineer can plug straight into their workflow. Where boundaries or neighbour relations are sensitive, we can add a focused boundary survey to the same visit.