In short
The four routes side by side — rebuild twenty-one to twenty-eight months, reconstruction eighteen to twenty-four, A&A fifteen to twenty-one, interiors alone six to nine — and where the time goes inside each. Three to six months of design and approvals come before anyone is on site. The piece separates the delays nobody controls from the ones the owner does, and explains what can genuinely be compressed and what cannot.
The four routes, side by side
| Route | Total, first meeting to handover | What it involves |
|---|---|---|
| Rebuild | 21–28 months | The house comes down and a new one is built to the full envelope |
| Reconstruction | 18–24 months | The existing structure is kept where it can be and rebuilt around |
| A&A | 15–21 months | The house stays; the plan, extensions and services change |
| Interior only | 6–9 months | No structural work; layouts, finishes, lighting and carpentry |
These are indicative durations based on typical KAPA projects; actual timelines depend on authority approvals, site conditions and the scope you choose.
The comparison people most often need is rebuild against A&A, because it is the decision most enquiries are stuck on. The honest version is that an A&A saves around six months and a meaningful share of the cost, and buys you a compromised plan wherever the existing structure will not move.
Where the time goes before anyone is on site
Owners usually arrive with a construction period in mind and leave out everything before it. Three to six months of design and approvals come first, and that is where the calendar is actually decided.
- Discovery and concept design. Establishing what you want, testing it against what the plot permits, and arriving at a layout and a preliminary budget everyone agrees on. A clear brief moves quickly. A family still deciding between four bedrooms and five does not.
- Schematic design. Plans, elevations and 3D visuals. Finishes decisions begin here, and they are the most common cause of drift.
- Authority submission. URA planning permission, then BCA building plan approval, with PUB, SCDF and others alongside. Comments and resubmission are normal; a programme that assumes first-time approval is optimistic.
Four to six weeks of indecision at concept stage is cheap. The same four to six weeks on site is not.
Why the design phase is not dead time
Months of design and approvals feel like nothing is happening. What is actually happening is that every expensive decision is being made while it is still cheap to change.
Compressing this phase is the most reliable way to make a project late. Decisions deferred into construction cost money and weeks, and they arrive when there is no slack left.
On site: where the months go
Construction runs in the order a building must: demolition and site set-up, then piling and foundations, then the frame and roof, then the envelope, then services and fit-out, then external works, inspections and handover. Stages overlap, which is why the total is shorter than the sum of the parts.
Two things surprise almost everyone. The house looks nearly complete from the road long before it is — the envelope closes at roughly the halfway mark, and the rest of the time is invisible from outside. And fit-out, the stage that looks like finishing touches, is the longest single stage on site.
What moves the number
| Cause | Who controls it |
|---|---|
| Authority queries and resubmission | Partly the design team: a scheme that respects the guidelines is queried less |
| Ground conditions found after demolition | Nobody fully, though proper site investigation reduces the surprise |
| Long-lead items ordered late | The owner and the team: specialist glazing, stone and carpentry take months |
| Changes of mind after the drawings are approved | Entirely the owner |
| Sustained rain during excavation and external works | Nobody |
The two that owners control — long-lead items and changes of mind — are the ones that most often decide whether a project finishes on time.
What can genuinely be compressed
Not much on site. Concrete cures at its own pace, and finishing trades cannot be doubled without a cost to quality.
What can be compressed is the gap between design, buildability review and submission — which is exactly what one team holding design and construction together is set up to do. The other real lever is decisiveness: freeze the design, choose finishes early, order long-lead items ahead of need, and resist changes once the contract is signed.
Key takeaways
- Rebuild 21–28 months, Reconstruction 18–24, A&A 15–21, Interior 6–9.
- Three to six months of design and approvals come before construction starts.
- An A&A saves around six months and accepts a compromised plan in exchange.
- Late decisions are the most expensive kind of delay, and the most avoidable.
Questions people ask
Not from first meeting to moving in. Design and authority approvals alone take three to six months, and a rebuild's construction takes well over a year. Twelve months end to end is not a realistic plan for a rebuild.
