Home Renovation Math: Measure the Room, Not the Guess

What this book teaches

One real box room, finished — floor down, walls flat and warm, skirting on, door hung and cased, window trimmed, the lot painted, and a builder's quote for the same work taken apart and checked against it. Two columns run through every chapter: the demo room worked in full down one side, your own room in the blanks down the other. Along the way: why the second coat is the one people forget; how a room that reads "3.60" at one end and "3.64" at the other changes an order, a set-out and a mitre; the rebalance that stops a flooring layout ending in a sliver; battens counted the right way (n gaps, n+1 posts); coverage rates that scale inversely with thickness; a corner's real angle from two tape marks, and the gap a plain 45° mitre leaves when the corner isn't square; a door's lining and architrave sized entirely from the leaf; and the tax that a naive "take 20% off" always gets wrong. Every chapter also carries a boxed, skippable Does It Pay? section — what the numbers cost, save and sell for.