Contingency for a £250,400 renovation of a 1,510 sq ft London coastal home

[makeTheCanvas]

I want to keep enough cash outside the works to finish the project properly, but the unknown condition of the building makes it hard to set that reserve. The current figure is £250,400 for a 1,510 sq ft coastal home in London, covering kitchens, bathrooms, surfaces, electrical investigation and some energy-efficiency work without adding an extension.

Before choosing a contingency, I plan to focus on damp or corrosion, access to concealed plumbing, subfloors and anything likely to require opening up. Which survey questions and contractor exclusions would you insist on resolving? My working rule is that if targeted inspections reveal sound fabric and accessible services, I can retain the fuller design; if they expose structural repairs or difficult pipework, I will reduce the specification before committing to orders. I would also welcome views on when permit work should begin relative to those investigations.

 

[miro_ash]

For that scope, I’d provisionally hold 15–20% outside the working budget until the building’s condition is clearer. Ask whether the price excludes rewiring beyond visible faults, replacement pipework behind finishes, damp remediation, subfloor repairs, access equipment, making good and permit-related delays.

Also request a room-by-room sequence and dates by which tiles, kitchen units and electrical fittings must be chosen. Lead-time slippage can turn a sensible programme into expensive stop-start work.

 

[table.plain]

I wouldn’t pick the contingency percentage before clarifying what “coastal” means here and how much opening-up has already happened. Is there visible moisture, corrosion, failed sealant or staining, and are the bathrooms above finished rooms with poor plumbing access?

A condition survey plus targeted inspection of electrics, moisture-prone areas and accessible pipework should narrow the range. Then have contractors identify assumptions and exclusions in writing. No extension does not guarantee no structural work: rotten joists, damaged lintels or unsuitable floors can still appear once finishes come off.