# Fitting Out an Occupied Office

> Fitting out an occupied office changes the programme, not the scope. Work is phased with decant areas, noisy and dusty tasks move to evenings and weekends, barriers contain dust, services are isolated in agreed windows, and escape routes and fire systems keep working. Duration is longer than for an empty floor, so plan phasing before agreeing a date.

## What actually changes

The belief is that fitting out an occupied office while people work is the same job as
refurbishing an empty one, done a little more politely. It is not. The
**scope** is the same: the same partitions, ceilings, services and finishes.
The **programme** is different in almost every respect.

On an empty floor, work can run across the whole area at once, at any hour, with
services shut off as required. In an occupied office, every one of those
freedoms is limited by the people still working there. The consequence for a
decision-maker is that the date, the sequence and the cost of coordination all
change, even though the drawings do not.

## Phasing a fit-out in an occupied office

An occupied fit-out is built around phases: sections of the floor that are
handed to the contractor, worked on, finished and handed back in turn.

The phasing plan answers four questions.

- **How many areas are there, and how big is each?** Larger phases finish sooner
  but need more people moved at once.
- **Where do the displaced people go?** This is the decant area, and it decides
  the size of every phase.
- **In what order?** Some areas have to go first because they hold services that
  later areas depend on.
- **How is each phase handed back?** Cleaned, tested and safe, before the next
  begins.

The decant capacity is often the real constraint. If only a small number of
people can be moved at any time, phases must be small, and the number of phases
and the overall duration follow from that. This is why the phasing has to be
worked out with the client's facilities and HR teams, not just the contractor.

## Noise and dust: move it, contain it

Two kinds of activity disrupt working staff most: noisy work and dusty work.
Typical examples are demolition, breaking, drilling and cutting, chasing walls
and sanding. The controls are of two kinds.

**Move it.** The noisiest and dustiest activities are scheduled for evenings and
weekends, when fewer people are present. This is effective, but it has a
programme cost: fewer productive hours, and overtime or shift working for the
crew.

**Contain it.** For work that has to be done during the day, physical separation
controls where the noise and dust go. That means solid temporary barriers rather
than sheeting alone, sealed joints, controlled entry points, protection of
ventilation and air-handling routes, and cleaning at the end of each shift.

Dust control depends more on sealing and discipline than on the barrier material.
A well-built barrier with an unsealed gap, or a door left open, does very little.

## Disruptions and the control that manages each

| Disruption | Main control | What can go wrong |
| --- | --- | --- |
| Noisy work | Schedule for evenings and weekends; agree quiet hours | Overrunning into working hours |
| Dust | Solid barriers, sealed joints, end-of-shift cleaning | Gaps at ceilings, doors and service penetrations |
| Vibration | Method choice; notice to affected teams | Working close to sensitive equipment |
| Power shutdowns | Agreed windows; temporary supplies | Undocumented circuits taking down other areas |
| Water and drainage isolation | Isolate by section; drain-down planned | Valves that do not isolate what the drawing says |
| Air-conditioning disruption | Zone isolation; protect return air paths | Dust drawn into occupied zones |
| Fire alarm and detection | Zone isolation with a defined procedure | Detectors left covered or zones left disabled |
| Escape routes | Protected, signed routes maintained | Temporary partitions blocking a route |
| Lifts and access | Booked windows; protected routes for materials | Deliveries competing with staff at peak hours |
| Deliveries and waste | Off-hours movement; designated routes | Debris carried through occupied areas |

The table is not a checklist for every job. It shows a pattern: each disruption
has a control, and each control has a place where it typically fails.

## Services isolation and shutdown windows

Work on electrical, water, drainage and air-conditioning services usually
requires them to be switched off or isolated. In an occupied building, that
affects people.

The controls are agreements more than technology. Shutdown windows are agreed
with the building's facilities team in advance, and each isolation has a defined
scope, a duration and a person responsible for restoring it. Where a service
must stay on, a temporary supply or bypass is arranged.

The recurring problem is that the building does not always match its drawings.
An isolation valve or breaker that is expected to isolate one area turns out to
serve another, and a shutdown meant for one department affects three. This is
why the services survey, and the coordination of what is affected, is done before
the shutdown, as described in the article on the
[MEP coordination drawing](/blog/mep-coordination-drawing-what-it-shows).

Building services provisions are set out in **NBC 2016, Part 8**.

## Escape routes and fire-system continuity

This is the part of an occupied fit-out where care matters most, and where the
guidance has to come from the building's own fire consultant and authority, not
from a general article.

The framework is straightforward. While people occupy the floor, the escape
arrangements that protect them must keep working. Temporary barriers must not
block or lengthen an escape route without that being agreed. Fire detection and
alarm zones affected by the works must have a defined procedure, so that
isolating a zone to avoid false alarms from dust does not leave an area
unprotected. Sprinkler isolations, if any are needed, must be planned, limited
in duration and communicated.

Fire and life safety provisions, including occupancy and escape, are in
**NBC 2016, Part 4**. What applies to a particular building, and what
arrangements are acceptable during works, must be agreed with the building's fire
consultant, the facilities team and, where relevant, the authority having
jurisdiction. This is a matter to be raised at the start of planning, not on the
day work begins.

## Lifts, access and logistics

Materials, waste and people all use the same lifts and corridors. On an empty
floor, that is a scheduling matter. In an occupied building, it competes with the
people already there.

Lift bookings, protected routes for materials, and delivery times outside peak
hours are worth planning explicitly. So are the access arrangements for the
contractor's workforce and how each phase is separated from the occupied area at
entry. Building management often has its own rules (see [landlord fit-out guidelines](/blog/reading-landlord-fit-out-guidelines-before-design)) on when goods lifts may be used
and how routes must be protected, and those rules become constraints on the
programme.

## Why the overall duration is longer

Putting the points together explains why an occupied fit-out takes longer than
the same work on an empty floor.

- Work proceeds area by area, not across the floor at once.
- Each phase needs setting up and protecting before work, and clearing and
  testing after.
- Noisy work is restricted to certain hours, which reduces productive time.
- Shutdowns can only happen in agreed windows, so services work waits for them.
- Materials move at restricted times, through restricted routes.
- People moving in and out between phases take their own time.

None of these is a failure. Together they are simply what an occupied
refurbishment is, and the honest programme shows it.

## Common mistakes

**Agreeing a completion date before the phasing is planned.** The date depends
on the number and size of phases, the decant capacity, the hours available and
the shutdown windows. Fixing it first forces those to be squeezed later, usually
at the expense of the people in the office.

**Assuming the decant is free.** Moving people costs time, and somewhere must
have capacity for them.

**Treating dust barriers as a one-off installation.** They need inspection,
repair and daily cleaning, not just building.

**Leaving fire detection to chance.** A detector covered to stop false alarms,
and never uncovered, is a hazard that outlasts the works.

**Not checking what an isolation actually isolates.** The shutdown affects more
than intended.

**Keeping staff uninformed.** People who know what is happening and when tolerate
disruption better, and complaints tend to fall.

## What to ask

- Has the phasing plan been drawn up, and who has agreed to the decant?
- Which activities will be done outside working hours, and what does that do to
  the programme?
- How are dust and noise contained during the day?
- Which services will be shut down, when, and for how long?
- How are escape routes and fire detection maintained during the works, and who
  has approved that?
- How are materials and waste moved through the building?
- How will occupants be informed?

## Standards referenced

Fire and life safety provisions, including occupancy and escape, in
**NBC 2016, Part 4**; building services provisions in **NBC 2016, Part 8**.
Arrangements for maintaining escape routes, fire detection and alarm and sprinkler
protection during works, and the permissions required for shutdowns, must be
agreed with the building's fire consultant, the facilities team and the authority
having jurisdiction.

## Frequently asked questions

### Does fitting out an occupied office change the scope of work?

Not usually. The same walls, ceilings, services and finishes are built. What changes is the order and the hours: the work is broken into phases, the disruptive activities are moved to times when fewer people are present, and every phase needs its own protection and services arrangements. That is why the effect shows up in the duration and the coordination effort rather than the drawings.

### Why does an occupied fit-out take longer than an empty floor?

Because work cannot run continuously across the whole floor. It proceeds area by area, with people moved in and out between phases. Noisy activities are limited to certain hours, and each phase needs setting up and protecting before work and clearing after. Productive hours are fewer, and the handover between phases adds its own time. The programme should show this rather than assume an empty-floor duration.

### What is a decant area and why does it matter?

A decant area is space where staff are temporarily moved while their own area is being worked on. It could be a section of the same floor, another floor or another location. The whole phasing plan depends on it, because the number of people who can be moved at once decides how large each phase can be, and therefore how long the whole job takes.

### How is dust kept away from working staff?

By physically separating the work area from the occupied area, and by controlling how dust leaves the work area. Typically that means solid temporary barriers rather than sheeting alone, sealed joints, controlled entry points, protection of ventilation and air-handling routes, and cleaning at the end of each shift. How effective it is depends on sealing and discipline more than on the barrier material.

### Can fire alarms and escape routes be affected during the works?

They can, and this is where the most care is needed. Detectors near dusty work can be triggered, sprinkler or alarm zones may need to be isolated, and partitions can obstruct escape routes. Fire and life safety provisions are in NBC 2016 Part 4, and how to maintain protection during the works must be agreed with the building's fire consultant, facilities team and the authority having jurisdiction.

### When should the completion date be agreed?

After the phasing plan is drawn up, not before. The date depends on the number and size of phases, the decant capacity, the hours available for noisy work and the shutdown windows the building will allow. A date agreed first and a phasing plan fitted around it later is the most common reason an occupied fit-out overruns or compromises the people working in it.

## Sources

- [NBC 2016, Part 4](https://www.bis.gov.in/standards/national-building-code/?lang=en) — Fire and life safety - occupancy and escape
- [NBC 2016, Part 8](https://www.bis.gov.in/standards/national-building-code/?lang=en) — Building services

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Source: https://hagerstone.com/blog/fit-out-in-an-occupied-office-phasing-noise-and-dust