You've signed off the drawings for the rear extension in South Norwood, the steel's ordered, and then the roofer turns up before the first-fix electrician has pulled a single cable through the new rafters. Nobody drew that clash on a plan. But it happens, and it's usually the homeowner who ends up paying for it.
A piece in Construction Magazine UK made a point that every builder in Croydon already knows: coordinated drawings don't guarantee a coordinated build. Their example was plant that couldn't be craned in once the roof was on. On a house extension, the equivalent is the 4.2m steel that has to go over the garden wall before the scaffold boards block the side return.
How we sequence an extension
So we plan the order properly. Trench-fill foundations go in first, poured to the depth the Building Control inspector signs off, then block and beam, then the cavity walls go up with wall ties at 750mm horizontal centres. Lintels are bedded before the roof timbers arrive, not after. First-fix pipework and cables go in while the walls are still open, and the plasterer only comes in once the roof is watertight and the screed has had its seven days.
It sounds obvious written down. On a loft conversion in Bromley or a kitchen knock-through in West Wickham, though, one trade running a day late can push the next three back a week. And a week on site is real money, and real disruption for the family living with it. Agreeing the order, and who needs access when, before a brick is laid saves arguments later. It also stops the variations that creep in when somebody changes their mind about a socket position after the plaster's on.
If you're planning an extension or loft conversion around Croydon, Bromley or West Wickham, we'll walk the job with you and talk through the sequence before you commit to anything. Have a look at how we work, or ring and we'll arrange a visit.