Retrofitting an Occupied Office: Working Around People

Why this is a different kind of project

The scope may be identical to an empty-floor fit-out. The constraints are not.

You are now delivering construction inside a functioning workplace, where noise, dust, isolations and access all affect people who are trying to do their jobs — and where a mistake with a fire alarm isolation or an escape route is a safety matter, not an inconvenience.

Decant space shapes everything

Start here, because it determines the shape of the whole project.

The number of phases, their size and their sequence all follow from how many people can be moved at once, and to where. With generous decant space, phases are large and the programme is shorter. With none, phases shrink and the project stretches.

Options worth pricing against the cost of a longer programme:

• Temporary space elsewhere in the building
• Denser temporary seating in the areas still in use
• Increased working from home during specific phases
• Short-term space in a nearby building

It is frequently cheaper to secure decant space than to absorb the extra months that its absence causes.

What has to keep working

Must continue	Risk during works
Escape routes	Blocked, re-routed without approval
Fire detection and alarm	Isolated for works and not reinstated
Air conditioning and fresh air	Zones isolated; occupied areas suffer
Power and data	Circuits shared across the boundary
Lighting	Circuits cut in the work area feed occupied space
Toilets and pantries	Taken out of use without an alternative

Two rules make this manageable:

Plan isolations in advance, with a register of what is being isolated, by whom, for how long, and who reinstates it. Fire system isolations in particular need a formal process, agreed with the fire consultant and the authority having jurisdiction, under NBC 2016, Part 4.

Prove escape routes for every phase, on a drawing, before that phase starts.

Separation, not sheeting

Dust and noise control fail when they rely on goodwill.

• Sealed temporary partitions — full height to the slab where possible, not polythene draped over a frame
• Negative pressure in the work area where practical, so air moves inward
• Dedicated material routes and agreed lift times
• Boundary cleaning as a scheduled activity, not an occasional one
• Out-of-hours working for noisy operations, within the landlord's permitted hours

Agree these as rules at the start. Negotiating them weekly wastes everyone's time and produces inconsistent standards.

Survey before you design

Refurbishment risk lives above the ceiling and behind the walls.

An opening-up survey before design routinely finds that existing services do not match the drawings, that capacity is lower than assumed, that structural conditions differ, or that legacy materials are present in older buildings.

Every one of those is cheap to design around and expensive to discover mid-phase with people sitting next door. This survey is the highest-value early spend on any refurbishment.

Existing services capacity in particular — electrical supply, cooling, fresh air — should be verified against NBC 2016, Part 8 requirements for the intended occupancy by the project's MEP consultant, not assumed from the original design.

Sectional completion belongs in the contract

Each phase is effectively handed over separately, which means each needs its own completion, its own snagging and its own defects liability start date.

Arranging that after the contract is signed is difficult. Writing sectional completion in from the start is straightforward.

Communication is part of the scope

The client should tell staff, in advance and consistently:

• What is happening, where, and when
• When noise is expected, and how long it will last
• Where to sit, and what changes about their route, toilets and pantry
• Who to raise a problem with

Most complaints on occupied refurbishments are about surprise rather than disruption.

Standards referenced

Fire and life safety provisions, including escape routes, in NBC 2016, Part 4; building services provisions in NBC 2016, Part 8. Escape arrangements during works, fire system isolations and services capacity for a specific project must be established by the project's fire and MEP consultants and agreed with the landlord and the authority having jurisdiction.