Quick answer
A window programme on an occupied building is a logistics job wrapped around a joinery one. The joinery itself, aluminium or timber, double-glazed or re-glazed, is well understood. The hard parts are scaffolding safely over an occupied building, keeping each unit weathertight and secure between the old unit coming out and the new one going in, and working around residents who are living there the whole time. Done to a programme, a whole building can be re-windowed unit by unit without anyone moving out, with larger works independently signed off.
How a whole building gets re-windowed while occupied.
Key points
- Replacing windows on an occupied building is mostly logistics: scaffolding, weathertightness between units, and working around residents.
- Aluminium and timber joinery each have their place; double-glazing and re-glazing are different scopes with different costs.
- Each opening is surveyed and the joinery made to that measure, so the swap is fast and the unit is weathertight the same day.
- Larger works are scaffolded and can be independently signed off, which is how a client gets assurance beyond our own word.
- The lead time is procurement: the joinery is made to order, so the install date is set once the units are on the way.
Windows are the maintenance job that looks straightforward and is full of hidden coordination. Take one out and there is a hole in an occupied home that has to be weathertight and secure before the crew leaves. Do it across a whole building and you are scaffolding over people's homes, sequencing units so nobody is exposed, and keeping every resident informed. We ran exactly this kind of programme replacing windows across a building in Ōrākei, scaffolded and independently signed off, which is the sort of work that proves a maintenance contractor can scale past kitchens.
Aluminium, timber, double-glazing and re-glazing
The joinery choice depends on the building. Aluminium joinery is the workhorse for most NZ buildings: durable, low maintenance and available double-glazed. Timber joinery suits character and heritage buildings where the look matters and matching the existing profiles is the job. Double-glazing is a full unit replacement that lifts warmth and cuts condensation and noise; re-glazing replaces the glass in a sound frame, which is the right, cheaper answer when the frames are fine and only the glass or a failed seal is the problem. Part of the job is telling you which of those you actually need.
| Situation | Usually the answer | Why |
|---|---|---|
| Frames sound, glass failed | Re-glaze | Keep the frame, replace the glass |
| Old single glazing, cold/damp | Double-glazed units | Warmth, less condensation and noise |
| Aluminium frames worn out | New aluminium joinery | Durable, low-maintenance replacement |
| Heritage / character building | Timber joinery to match | Preserves the look and the profiles |
Working over an occupied building
The safety and weathertightness are where a window programme is won or lost. Scaffolding goes up over homes people are living in, so it is planned, certified and coordinated with the building's own rules, the same overlapping-duty coordination that governs any contractor on a site someone else runs. Each opening is surveyed and the joinery made to that exact measure beforehand, so the actual swap is quick: the old unit out, the new one in, sealed and weathertight, the unit secure again the same day. Residents are told which day their windows are being done and what to expect, because it is their home the scaffold is wrapped around.
Assurance on larger works
On a bigger window programme a client is right to want more than the contractor's own assurance. Larger works can be independently signed off, in our case by a partnered Master Builders firm that audits and certifies the job. That independent check is the same standard we apply to structural kitchen and building work, and it is the difference between trust us and here is a third party who verified it. For a portfolio owner making a call across a whole building, that sign-off is worth having.
Windows also rarely travel alone. A re-window often runs alongside repainting the reveals, flooring make-good under the opening, or other maintenance, so handling it under one contract means the trades are coordinated rather than tripping over each other on the scaffold. You can see our window scope on the windows service page.
Frequently asked questions
Can you replace windows while we stay in the building?
Yes. A window programme on an occupied building is run unit by unit, with each opening surveyed and the joinery made to measure beforehand, so the swap is quick and the unit is weathertight and secure again the same day. Scaffolding and access are planned around the residents, who are told which day their windows are being done.
What is the difference between re-glazing and double-glazing?
Re-glazing replaces the glass in an existing sound frame, which is the cheaper answer when the frames are fine and only the glass or a seal has failed. Double-glazing is a full replacement of the unit with an insulated glass unit, which lifts warmth and cuts condensation and noise. The right one depends on the state of your existing frames.
Should I choose aluminium or timber joinery?
Aluminium joinery suits most NZ buildings: it is durable, low-maintenance and available double-glazed. Timber joinery suits heritage and character buildings where the look matters and the new units need to match existing profiles. The choice depends on the building, its age and whether appearance or low maintenance is the priority.
How long does a window replacement take per unit?
The install itself is usually quick, often within a day per unit, because each opening is surveyed and the joinery made to measure in advance. The longer part is the procurement lead time while the joinery is made to order. Once the units arrive, the install dates are set and the swap is fast and weathertight.
Do you scaffold for window work on an occupied building?
For larger or higher works, yes. Scaffolding over an occupied building is planned, certified and coordinated with the building's own health-and-safety rules, because residents are living there throughout. Access, exclusion and weathertightness are all planned so the building stays safe and secure while the programme runs.
Can the window works be independently signed off?
Yes. On larger works we can have the job independently audited and signed off by a partnered Master Builders firm, which gives a portfolio owner third-party assurance rather than just our own word. It is the same independent-QA standard we apply to structural building work, and it matters most on a whole-building programme.
If you have a building that needs re-windowing without moving anyone out, that is work we do: surveyed unit by unit, made to measure, scaffolded and weathertight, with independent sign-off on the larger works. Tell us the building and how many openings and we will survey and price the programme.