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Guidance

CDM 2015, explained properly

31 pages answering the questions people actually search for, written from the regulations and HSE guidance rather than from other consultants' websites. Every page names its sources and carries the date it was last reviewed.

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Does a house extension need a CDM principal designer?

Usually yes. Why almost every extension crosses the more than one contractor test under CDM 2015, what the appointment involves, and what it costs.

What happens if the client does not appoint a principal designer?

The role does not disappear. Regulation 7(2) hands it to the designer in control of the pre-construction phase on domestic work. What that means in practice.

CDM principal designer vs Building Regulations principal designer: what is the difference?

Two separate principal designer roles, two sets of regulations, and one project that can need both. The trigger for each, who appoints, and what they each do.

What should pre-construction information contain?

The four headings HSE guidance requires, what they mean on a small project, and a worked list for a domestic extension.

There are also free tools. A principal designer checker, an F10 threshold checker, a dutyholder map, a pre-construction information checklist and a construction phase plan readiness checker. All of them give you a usable answer whether or not you ever buy anything. Open the tools.

Principal designer

What the role is, when it has to be appointed, and what it costs.

What is a CDM principal designer?The CDM 2015 principal designer role explained: what the appointment covers, who can hold it, and when it is required.When is a CDM principal designer required?The single test that decides whether a CDM principal designer must be appointed, what counts as a contractor, and when the appointment has to be in place.What does more than one contractor mean under CDM 2015?The phrase that decides whether a principal designer is required. What counts as a contractor, and whether they have to be on site together.Do subcontractors count as contractors under CDM?Yes, and it usually changes the answer on a domestic project. Why subcontracted trades count towards the more than one contractor test under CDM 2015.Does a house extension need a CDM principal designer?Usually yes. Why almost every extension crosses the more than one contractor test under CDM 2015, what the appointment involves, and what it costs.Does a loft conversion need a CDM principal designer?Almost always yes. Loft conversions carry two risks worth coordinating before work starts: the existing roof, and the structure being cut into.Does CDM apply to domestic projects?Yes. What changes for a domestic client is who carries the duties, not whether the regulations apply. Regulation 7 explained, including the DIY line.What are the CDM principal designer's duties?Regulation 11 and regulation 12, set out in plain English, with what each duty looks like in practice on a small project.When should the principal designer be appointed?As soon as is practicable and before the construction phase begins. Why design stage is the point of the role, and what to do if you are late.How much does a CDM principal designer cost?What the market charges, how fees are usually structured, what moves the price, and ClearCDM's published figures.

For designers

For architects, architectural designers and engineers: what lands on you, what does not, and how to place the role somewhere else.

What happens if the client does not appoint a principal designer?The role does not disappear. Regulation 7(2) hands it to the designer in control of the pre-construction phase on domestic work. What that means in practice.Am I automatically the CDM principal designer if the client appoints nobody?For architects, designers and engineers. When regulation 7(2) makes you the principal designer by default, what it does not do, and the two clean ways out.Can an architect refuse to act as CDM principal designer?You can decline the appointment. What you cannot do is decline your designer duties, or switch off regulation 7(2) with a clause. What to do instead.Does appointing a separate principal designer remove the architect's CDM duties?No. Regulation 9 duties belong to anyone who prepares or modifies a design and do not transfer. What changes is who coordinates the project.CDM responsibilities for architects on domestic projectsA guide for design practices working on houses: what regulation 9 asks of you, what regulation 7 does when nobody is appointed, and where the risk sits.How can a practice outsource the CDM principal designer role?The three procurement routes open to a design practice, what makes an appointment effective, and the questions worth asking a specialist before you recommend one.

Which role is which

Two principal designers, one project, and the roles CDM 2015 replaced.

CDM principal designer vs Building Regulations principal designer: what is the difference?Two separate principal designer roles, two sets of regulations, and one project that can need both. The trigger for each, who appoints, and what they each do.Can the same person be both principal designers?Yes, where they are competent for both, and the Building Regulations even provide a certification shortcut. Why that shortcut is worth using carefully.What happened to the CDM coordinator role?The CDM coordinator was abolished when CDM 2015 replaced CDM 2007. What replaced it, what changed in the process, and why the old title still turns up.

Pre-construction information

The document the whole thing turns on: what it is, what goes in it, and who provides what.

What information should a designer provide to the principal designer?What regulation 9(3) and 9(4) actually ask for, what it looks like on a small project, and what is not worth sending.What is pre-construction information?The CDM 2015 definition, the three tests it has to meet, who provides it and who it is for.What should pre-construction information contain?The four headings HSE guidance requires, what they mean on a small project, and a worked list for a domestic extension.Who prepares the pre-construction information?The duty sits with the client. The principal designer assists, and on a domestic project regulation 7 moves the client duty. Who does what, in practice.

For contractors

Construction phase plans, principal contractor duties, and what you should be given before you start.

What is a construction phase plan?The contractor's document for running the site safely: what has to be in it, how long it should be, and what HSE guidance says to leave out.Who prepares the construction phase plan?The principal contractor, or the contractor on a single contractor project. What the client, the principal designer and a consultant can and cannot do.Does every construction project need a construction phase plan?Yes, wherever CDM 2015 applies. There is no size threshold, and the single contractor route is the one people miss.What are the principal contractor's duties under CDM 2015?Regulations 12 to 14 in plain English, plus the extra duties a principal contractor picks up on a domestic project under regulation 7.

The documents

Health and safety files and F10 notifications, with the thresholds and the arithmetic.

What is a health and safety file?The file a completed project leaves for the next one: what goes in, what HSE guidance says to keep out, who prepares it and how long you keep it.When is a health and safety file required?Only on projects with more than one contractor. Who prepares it, what happens if the principal designer leaves early, and what to do if a file already exists.What is an F10 notification?The notice given to HSE before a notifiable construction project starts: the thresholds, who has the duty, how it is submitted and what has to be displayed on site.When is a construction project notifiable to HSE?Both thresholds explained with worked arithmetic, including why most domestic projects are well below them.

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