A three-building masterplan does not run on one schedule, one contract or one lien clock. Treating it as though it does is the fastest way to discover, months in, that a decision made for Building A has quietly bound Buildings B and C to a timeline nobody chose on purpose.
Key takeaways
Phasing exists because a multi-building project rarely makes sense to build, finance or sell as one indivisible block. Splitting the site into buildings, or a building into blocks, lets a developer start leasing or closing sales on the first phase while the second is still in the ground, and lets a lender fund against progress that is real and inspectable rather than a single distant completion date. The upside is real. It is also the reason a phased project needs more structure around it than a single-building job, not less — every phase boundary is a place where a schedule, a contract and a statutory clock can quietly diverge.
Ontario's Construction Act requires whoever pays for services or materials to hold back 10% of the value of the work, and that requirement attaches to the contract, not to the project as a whole. Phasing a project does not reduce that 10%, and it does not let an owner net one phase's overrun against another phase's holdback. What phasing genuinely changes is the timing of release: phased or annual release changes when portions of that holdback can be paid out, not how much is required to be held back in the first place. Confusing the two is a common and expensive mistake — a contractor who assumes a phased structure lets an owner hold back less has read the wrong half of the rule.
The second thing that changes is the lien clock, and this is where phasing has real teeth. A certificate of substantial performance is typically published per contract, and a multi-building project is often structured as separate contracts, or at minimum separate substantial-performance milestones, per building. Ontario's rule is that a lien must be preserved within 60 days of whichever triggering event applies — publication of a certificate of substantial performance, completion, or the claimant's own last supply — and perfected within 90 days after that. If Building A reaches substantial performance in month 14 and Building B in month 22, a subtrade working across both buildings can be looking at two live, independently-running lien clocks at once, each with its own 60-day and 90-day deadlines.
The scheduling side of phasing is a separate problem from the legal side, and it needs its own discipline. Procore's Schedule tool lets a team import an existing schedule built in Primavera P6, Microsoft Project or the MPX format and then work from it as the single source of truth, rather than rebuilding phase logic by hand inside a field tool that was never designed to carry critical-path dependencies. For a phased project this matters more than it does on a single building: the dependency that actually drives risk is rarely internal to one phase, it is the handoff between phases — site access for Phase 2 mobilization that depends on Phase 1 hoarding coming down, a shared crane or hoist that has to be released from one building before the next can use it, or a shared services connection that has to be live before either building's occupancy can proceed.
A schedule that shows each phase as an isolated block, with a single dependency arrow connecting them, understates that risk. The handoff itself — demobilization, inspection sign-off, site cleanup, access reconfiguration — usually needs its own duration and its own named owner, not a zero-duration milestone. Projects that treat the handoff as instantaneous are the ones that discover, when Phase 1 finishes two weeks late, that Phase 2's mobilization was never actually able to start on the date the master schedule assumed.
The contract structure should mirror how the project is actually going to be built and sold, not how it was originally conceived on a single-date pro forma. Where each building will close, lease up or be inspected separately, the cleanest approach is usually separate contracts, or at minimum separately defined substantial-performance milestones within one contract, so that holdback release and lien clocks track reality per building rather than being forced to wait for the whole project to finish. A single contract with one completion date, applied to a project that is functionally delivered as three separate buildings months apart, tends to produce exactly the dispute described above: a subtrade who finished Building A's work first and reasonably expected to be paid out on it, discovering the contract's completion definition ties everyone's final payment to Building C.
The same logic extends to how draws are structured against a construction lender. A phased project's financing is typically drawn against phase-specific milestones for the same reason the contracts are separated — a lender funding Phase 2's foundation work wants that draw measured against Phase 2's own progress, not blended into a single project-wide percentage-complete figure that could mask one phase running ahead of schedule while another has stalled.
Worked example — two lien clocks running at once
A general contractor is building two townhome blocks on one site, structured as two separate contracts. Block 1 reaches substantial performance and the certificate is published on March 1. Block 2, delayed by a foundation issue, reaches substantial performance and its certificate is published on May 15 — 75 days later.
A subtrade that supplied both blocks now has two independent 60-day preservation windows: it must preserve any lien against Block 1 by April 30, and any lien against Block 2 by July 14. Treating the project as one job with one clock — and waiting to see how the whole site finishes before acting — would have let the Block 1 window close entirely before the trade ever looked at it.
The 10% holdback on each contract is unaffected by any of this: each block's payer still holds back 10% of that block's contract value, and the March and May substantial-performance dates only govern when each block's holdback becomes eligible for release, not whether the 10% was owed in the first place.
Related reading: the draw schedule a lender will fund and value management at the design stage.
No. The 10% holdback requirement attaches to each contract regardless of how the overall project is phased. What a phased or annual release changes is when accrued holdback can be paid out, not how much is required.
Yes, if each generates its own certificate of substantial performance on its own date. A trade working across both buildings can have two independently-running 60-day preservation and 90-day perfection windows to track.
Where each phase will close, lease up or be inspected on its own timeline, separate contracts or clearly separated substantial-performance milestones let holdback release and lien clocks track each phase's real progress rather than being tied to the last phase to finish.
The handoff between phases — demobilization, inspection sign-off and access reconfiguration — is often modelled as a zero-duration milestone when it actually needs its own duration and a named owner, which is where phased schedules most often slip.
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