Lock-up is the stage everyone can see — roof on, walls clad, windows in, doors lockable — and the stage lenders treat as a major drawdown milestone. That combination makes it the point where money and definitions collide: trades want to claim it early, banks want it verifiably complete, and the gap between those two is yours to manage.
What lock-up actually means
There’s no single legal definition, but the working standard — and what a bank’s valuer looks for — is:
- Roof covering complete (not just sarking), with flashings and penetrations sealed.
- External walls clad — brickwork, cladding or render substrate done.
- Windows and external doors installed and lockable.
- The building secure and weathertight — you can lock it and rain stays out.
Your trade contracts should use the same definition your loan uses. If the builder’s “lock-up” claim arrives with temporary ply where the front door goes, the definition gap becomes a payment argument — settle it in writing at contract time, not on the driveway.
The water-entry hunt
Lock-up is your last cheap chance to catch the defects that become mould and rot claims years later. Before internal linings go anywhere near the walls:
- Flashings at every window head, sill and penetration — present, lapped correctly, draining out not in.
- Sarking and wraps — continuous, taped, not shredded by the cladders.
- Weep holes in brickwork open, not mortared shut.
- Roof penetrations (flues, vents, skylights) flashed to the manufacturer’s detail.
- A hose test on anything doubtful. Ten minutes with a hose now versus an insurance argument in year four.
Photograph all of it. Water damage is the single biggest category of building dispute in Australia, and your photo file is the difference between a claim and a conversation.
Trades and sequence at this stage
Roofer, bricklayer/cladder, window installer, and the returning rough-in trades finishing external penetrations. The sequencing trap is scaffold: it comes down when the roof and cladding are genuinely finished, not when the hire bill gets annoying. Bringing scaffold back for missed flashings costs more than the extra fortnight of hire — and gutters, fascia and high flashings done off ladders get done badly.
The paperwork this stage generates
Roofing installation warranty, window/glazing compliance certificates (safety glass locations especially), cladding system documentation, termite management certificate if barriers were extended, and your flashing/wrap photo set. Where an approval requires it, the certifier inspects at weatherproofing-relevant points — check yours so nothing gets clad ahead of an inspection.
Next in the sequence: the fixing stage, where the inside of the house appears — and the money runs fastest.
Before you get here
Lock-up disputes are contract disputes wearing hi-vis: the definition, the payment trigger and the inspection points all should have been fixed on paper months ago. The Pre-Start Review locks those down before the slab — and the contract negotiation guide covers the payment-schedule terms that make this stage boring.