Free CDM tool

Does CDM 2015 apply to my project?

Answer a few simple questions to understand whether CDM 2015 is likely to apply and what your project structure may mean in practice.

Takes about 1 minute · No sign-up required

Construction work

What does the planned work mainly involve?

Choose the option closest to what will physically be done, whatever the job is called. Size, cost and duration do not matter here.

New build or extensionConstructing a new building, extension or other structure, including civil engineering work.

Alteration, refurbishment or fit-outAltering, converting, renovating or fitting out an existing building or structure.

Repair, upkeep or redecorationRepairing, maintaining or redecorating a building or structure, such as a roof, wall or fixed plant.

Work on fixed servicesInstalling, commissioning, maintaining, repairing or removing electrical, mechanical, gas, telecoms, computer or similar services fixed within or to a structure.

Demolition or dismantlingDemolishing, dismantling or decommissioning a structure, or removing it or the waste it leaves.

Site preparation or groundworkSite clearance, ground investigation or excavation in preparation for an intended structure.

Maintenance — not sure what it involvesPlanned or reactive maintenance where it is not yet clear whether the building, plant or fixed services are worked on.

Something elseFor example a survey, cleaning, quarrying, or an activity that may not be construction work at all.

Not sureI need help deciding what the activity counts as.

Choose an answer to continue.

Last reviewed: 23 October 2026Checked againstCDM 2015 Regulation 2: definition of construction work, on legislation.gov.uk (opens in a new tab)HSE CDM FAQ: including whether CDM applies to all maintenance work (opens in a new tab)HSE summary of duties: including the domestic client and DIY position (opens in a new tab)

This checker works through your answers. The guides explain the detail behind them.

Guide
When does CDM apply?
The detailed guide behind this checker: scope, small and domestic projects, maintenance work and the separate F10 question.
Guide
What is construction work under CDM 2015?
The legal definition of construction work, with the activities that fall inside and outside it.
Guide
Does CDM apply to domestic projects?
How the Regulation 7 domestic-client arrangements work, and where HSE draws the line at DIY.

Does CDM 2015 apply to my project?

What does the planned work mainly involve?

Read more on when CDM applies

When does CDM apply?

What is construction work under CDM 2015?

Does CDM apply to domestic projects?