Groundwork & Foundations

Demolish or Underpin

Anonymous user 03/03/2024 - 3.23 PM

I have recently been granted planning permission to extend my kitchen on the ground floor into a space behind the attached garage, (This will take around a third off the back of the garage to square off the new kitchen) and above, a first floor extension running over both the new kitchen and garage. Its a 1970s detached house near Bolton. Having got quotes for just the build/plumbing/electrics/plastering etc (No fittings) then a builder and inspectors in place, it seems that the garage foundations are not deep enough to take the extra floor. My builder has recommended that the garage be demolished (it's about 9ft x16ft) and rebuilt. The cost to do this is virtually the same price as the extension build, so doubling the price. Obviously, I was aware there could be an issue with the foundations but didn't realise how much it would cost. My architect has suggested that underpinning by pouring concrete under the garage (at least the two thirds of it as the other third is in the new build) might be an option. I am not looking for a 'cheap' job, but trying to get the best out of my budget. My builder won't do it, probably due to time. I am just looking for advice on what might be the best option. Many thanks Paul