A complete renovation starts with removing the old bathroom and taking it away, with the rest of the house protected on the way out. Then comes the part that decides how good the finished room will be: setting out the new layout, altering the pipework, running new hot, cold and waste services, forming falls where a shower or wet room needs them, and upgrading the electrics, lighting and extraction.
From there the room is built back up — walls prepared, wet zones fully tanked, floors levelled, underfloor heating laid where you've chosen it, tiles set out and fixed, then the bath, walk-in shower, WC, basin, vanity unit, taps, towel rail and mirrors fitted and tested. Finishing is where a renovation is judged: crisp silicone, sealed grout, a properly hung door, decorating made good and a room left clean.