The HSE Construction Sector document (Q&S Briefing (8) - Construction Division - Construction(Design and Management) Regulations 2015, "An approach to interpreting if an activity is construction work") as close to a concise guide as anything I've found. It states
"Q1. How do I decide if an activity is construction work?
A. The definition of construction work as set out in Reg 2(1) in CDM 2015 is broad, non-exhaustive
and is largely the same as it was in CDM 2007. Construction work may
take place within many industry sectors and CDM will apply if the activity falls within
the definition. Whilst it is not HSE’s role to provide a definitive interpretation (which
only a court can do), there follows general pointers as to how it should be construed
in cases of uncertainty.
There are two steps to determining whether an activity falls within the definition of
construction work, and therefore whether CDM 2015 applies.
Step 1 – the project/activity must fall within one or more of the three categories set
out in the definition, those being the carrying out of any;
• building work,
• civil engineering work, or
• engineering construction work*.
If the activity falls within any of these three categories, CDM 2015 does apply.
If the activity does not fall into any of the three categories, CDM 2015 does not
apply and Step 2 is not relevant.
Step 2 - If the activity falls into one of the three main categories, then the list of
specific construction activities in (a) - (e) are relevant and provide the second stage
to determining if an activity is construction work.
When considering (a) – (e), note that the activities in each relate to specific actions in
respect of a structure within the project, and should not be considered as
interchangeable.
There may be activities similar to those listed which may be considered, but they
should be seen in the context of the functions, and not just ‘made to fit’.
(a) the construction, alteration, conversion, fitting out, commissioning,
renovation, repair, upkeep, redecoration or other maintenance
(including cleaning which involves the use of water or an abrasive at
high pressure, or the use of corrosive or toxic substances), decommissioning,
demolition or dismantling of a structure;
This relates to activities involved with the building, alteration, upkeep etc.
decommissioning, demolition or dismantling of a structure.
*Note: The Engineering Construction Industry Association (ECIA) sets out engineering
construction work as the design, construction and maintenance of process plant across the
oil and gas, water, environmental, steel and metal, cement, glass, paper, brewing and
distillation, food, power generation, nuclear waste reprocessing, pharmaceutical production,
petrochemical and chemical sectors.
I love the bit about "it is not HSE’s role to provide a definitive interpretation (which
only a court can do)"