There is a moment in most renovations when the consents are signed, the builder is two weeks out, and the homeowner is standing in the half-emptied lounge with a crowbar and a bag of frustration. Pulling stuff out yourself is the cheapest hour of the whole project, and the most satisfying. It is also the bit most likely to surface something you weren’t planning on, and the bit that needs the clearest rules.

So, what can be safely stripped out before the trades arrive, and what should be left alone? Demolition before the trades arrive splits into three honest categories. The first is cosmetic strip-out. Think skirtings, architraves, carpets and underlay, cheap kitchen cabinetry, internal doors, wardrobe shelving, vanities, mirrors and dated light fittings. With a claw bar, a utility knife and a respirator, most owners can clear a room in an afternoon. A skip-bin hire pays for itself by lunchtime.

Before the skip arrives, a quiet hour spent sorting is worth it. Solid native timber doors, brass hardware, sash windows, cast-iron baths, exposed brick and matai or rimu flooring all have a second life either back in the house, on Trade Me and other online marketplaces, or through building recycling yards. Renovation-waste guidance from councils and building organisations points in the same direction. What goes in the skip is final. What gets set aside in the garage can pay for the new tapware.

The second is the category you do not touch without checking the build year. Anything built in New Zealand before about the year 2000 sits in the asbestos-possible window. Textured ceilings, vinyl floor tiles and their adhesives, eaves linings, fibre-cement boards in bathrooms and laundries, and the lagging around old hot-water cylinders are the usual suspects. WorkSafe’s homeowner guidance is unambiguous: if there is any doubt, a licensed assessor takes a sample before anything is disturbed, and removal of more than ten square metres of non-friable asbestos is a licensed-only job. The cost of testing is small. The cost of getting it wrong is your lungs, the neighbours’ lungs, and your insurance.

The third is the load-bearing and live-service category. Walls that look like partitions sometimes are not. The clue is rarely visible from the room side: it is the run of the floor joists above, the position of the wall relative to the bearers, and what is sitting on top in the roof space. If a wall runs perpendicular to the joists above it, treat it as load-bearing until a builder or engineer says otherwise. Inside the cavities are the easy-to-forget services, electrical runs, plumbing and sometimes a ducted heat-pump line. The rule there is simple: switchboard off at the main, water off at the toby, and if you find anything you were not expecting, stop and call the relevant trade.

The most useful conversation to have with the builder before they start is the demolition split. What do they want you to clear, what do they want to do themselves, and what do they want left untouched until they are standing in the room? An hour on the phone before the work begins usually buys you a fortnight on the back end.