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Foundations 75 “Your plans should identify all the load-bearing walls.” F oundations need to be dug according to a predetermined plan, and to have been accurately surveyed and set out. It is surprising just how often this is not done, and occasionally the ramifications can be very serious indeed, as completed houses turn out to be in the wrong place and subsequently have to be demolished. Your plans should identify all the load-bearing walls and the width of the trenches to be excavated. The depth of excavation is harder to predetermine and this is routinely decided by the building inspector on site. This is where things can get a little bit tricky, because if you have a difficult site, the foundation trenches may have to go down two metres, sometimes even more, below ground, which is expensive and potentially dangerous. Recent amendments dating back to 2013 demand that developers and private home builders demonstrate compliance with the design and the building regulations from the start to the end of the work. It starts with the commencement notice and reaches right through the build to a series of certificates that must be signed off on by an ‘assigned certifier’ and your foundations will be part of this. What your certifier is looking for is principally a good bearing on solid ground. However, you can never be certain just what lies beneath the ground until it’s opened up. This has led to professionals becoming more and more cautious about foundations and specifying loads more concrete or, increasingly, engineered or piled foundations. Winter 2016 Home & Build Winter 2016.indd 75 08/01/2016 4:32 p.m.