Should new distribution boards be thermally surveyed after an office fit-out?

Yes, but not on the day of practical completion. An empty floor carries almost no load, so a survey then shows little. Survey the new boards once the floor is occupied and running normally, usually within the first few months, and before the defects liability period ends, so anything found is still the fit-out contractor’s to put right.

Why practical completion is too early

A poor connection shows by the heat it gives off while current flows through it (see what load a survey needs). At handover, the lighting may be on but desks, kitchens, comms rooms and meeting rooms are not yet in use. The boards are carrying a fraction of the load they will see once people move in.

Data centres get round this with load banks at commissioning. Offices rarely do, so the practical answer is to wait for real occupation.

When to book it

After occupation: once the floor is fully in use and the heating or cooling season has started, so HVAC is working too.
Before the defects period ends: usually twelve months from practical completion. Leave time for the contractor to return (see the same question for data centres).
On a working day, mid-morning to mid-afternoon, when the floor is busiest.

Cat A and Cat B: whose boards are they?

In a Cat A fit-out, the landlord’s contractor installs the base distribution. In a Cat B fit-out, the tenant’s contractor adds the tenant’s boards, small power and any comms room supplies. Agree who is commissioning the survey and which boards are in scope, so findings go to the right contractor (see tenant boards in a landlord’s survey). Where the riser supplies were touched, include them (see rising busbar and rising mains).

What should be in scope

New floor distribution boards and the sub-main connections that feed them.
Comms and server room supplies, including any small UPS.
Tea points and kitchens, surveyed when they are in use.
Fan coil, VRF or air handling control panels installed or altered in the fit-out.
Any existing boards that were extended or had new circuits added.

What the survey gives you

A same-day report from Ti Thermal Imaging that locates every finding by board, circuit and phase, with the measured temperature, where it was taken, the difference in °C from a matching reference and the load at the time. It also gives a baseline for the building’s annual survey. Ti inspects and reports; the fit-out contractor or the building’s electrical contractor investigates findings with the circuit isolated and carries out the work.

What installation-stage thermography can find

On a London data centre build, commissioning thermography by our team found 16 busbar sections reading above 80 °C under test load, the highest 103.5 °C at a tap-off unit, while the installer was still on site. An office fit-out is smaller, but the principle is the same: new connections are best checked under real load, while the people who made them are still responsible for them.

Frequently asked questions

Can the survey be done before the tenant moves in?

Only if real load can be applied. Otherwise, wait until the floor is occupied.

Does the electrical contractor’s commissioning testing cover this?

No. Commissioning tests prove the installation is safe to energise; thermography shows how connections behave carrying everyday load.

Is it worth doing when we lease a fitted floor?

Often, yes (see surveys for due diligence when buying or leasing).