Should a thermographic survey be part of due diligence when buying or leasing a commercial building?

It is worth including. An electrical thermographic survey under normal working load shows which connections in the switchboards, distribution boards and busbar are running warmer than matching parts, with their location and measured temperature. That gives a buyer or incoming tenant a dated record of electrical condition before they take the building on, alongside the EICR rather than instead of it.

What it adds to the usual building surveys

A building survey looks at the fabric and services from the outside. An EICR tests the installation against BS 7671, and much of that testing is done with circuits isolated. Neither shows how the live connections behave while the building is carrying its normal load.

That is what thermography adds. With covers opened by the site’s authorised electrician, a thermographer images each connection live and records where any warmer-than-expected connection is. It is a short visit compared with the cost of finding a problem after completion.

Timing: the building needs to be in use

A connection only shows its condition when current flows through it. A survey of an occupied, working building tells you far more than one of an empty floor plate at a fraction of its normal load. We record the load with every image, and if a building is lightly loaded on the day, the report says so plainly, so nobody reads more into a clean result than it can carry.

For a vacant building, the survey is still possible, but its limits should be agreed up front. See what load a survey needs.

Who arranges access

Before completion or a lease start, the building still belongs to the seller or landlord. Their facilities team or electrical contractor needs to agree the visit and provide the authorised electrician who opens the panels. In a multi-let building, tenant boards need each tenant’s agreement as well; we cover that split in tenant boards in a landlord’s survey.

What the report gives you

For each finding: the board and way reference, a thermal and a visual image, the measured temperature and exactly where it was taken, the difference in °C from a matching reference, and the load at the time. Equipment that could not be opened or imaged is listed with the reason. That gives your advisers something specific to raise with the seller, and gives your maintenance contractor a list for the first year.

Ti inspects and reports. Any finding is for a competent electrician to investigate and put right; we do not carry out repairs.

At the start and end of a lease

A survey at the start of a lease, repeated at the end, gives landlord and tenant a dated record of electrical condition at each point, recorded the same way, to compare. Using the building’s own board references in both reports keeps that comparison simple.

New does not mean defect-free

Newly built or refitted buildings are not exempt. On one London data centre build, our commissioning thermography recorded 16 busbar sections reading above 80 °C under test load, the highest 103.5 °C at a tap-off unit, all on brand-new equipment. Installation defects of that kind are exactly what a survey under load is there to find.

Frequently asked questions

Does a thermographic survey replace the EICR?

No. They look for different things, and a building being bought or leased will usually need both. See does a thermographic survey replace an EICR?

Can the survey be done if the building is empty?

Yes, but with little load on the system it shows much less. The report records the load and says where that limits the result.

Who receives the report?

Whoever commissions the survey, usually the buyer, the incoming tenant or their adviser. The seller or landlord can be given a copy if both sides agree.