Groundwork is one of those parts you barely see when it’s done, but you definitely feel it if it’s done badly. Typically, you’re looking at site clearance, setting out, digging foundations, pouring concrete, building up to damp-proof course, installing drainage runs, and preparing the floor slab. After that, brickwork usually starts with matching the existing house detail as closely as possible, including brick size, bond pattern, mortar colour, and any soldier courses or lintel styles. I’ve seen a project where drainage was assumed to be simple, but once they opened the ground, they found an old run in the wrong place and had to reroute it, which added days and extra cost. Brickwork mistakes can be even more annoying because they’re visible forever. My practical tip is to ask for a quick “pre-start walk” where the builder shows you the setting out lines and explains where drainage will go, then take photos for your own record. In trying to wrap my head around this, I stumbled upon an interesting site that might help you. Before I forget, do not skip Building Control inspections at key stages, because catching issues at foundation and drainage stage is far easier than fixing them after the walls are up.
