19th August, 2021

CDM Planning Period And How Much Time You Need

The CDM regulations say that clients must allow sufficient time for each stage of the project, in fact, it's the first client duty. And this includes allowing enough time to plan how to carry out the project safely. But how much time do you need to allow for the planning period, to comply with CDM?

CDM Planning Period And How Much Time You Need header image

It's important to consider the time needed for planning and preparation on all construction projects. You know what they say, failing to prepare is preparing to fail. If you don't plan ahead, you're likely to run into problems that could have been avoided if you had considered them before you started. And these problems can cause delays, costs, and safety issues on site.

The Construction (Design and Management) Regulations (known as CDM) apply to all construction projects. And they say that clients must allow sufficient time for each stage of the project. Allocating sufficient time is so important it is the first legal duty of the client under CDM 2015. But how much time should be allowed to comply with this duty?

  1. —(1) A client must make suitable arrangements for managing a project, including the allocation of sufficient time and other resources.

This sufficient time is known as the CDM planning period, because in the previous 2007 version of the CDM regulations it was referred to as the "minimum amount of time before the construction phase which will be allowed to the principal contractor for planning and preparation for construction work". In other words, the time allocated to plan and prepare for the work.

Of course, you also need to allow adequate time for the construction period too. Rushing towards a finish date can be just as dangerous as rushing towards the start date. And, given sufficient planning time, the contractor can give a more accurate schedule for the work.

cdm client

Since the client is generally the person that sets the overall project goals (e.g. what they want and when they want it), the client has to be reasonable with those demands. If you want the job doing now and finishing yesterday, you could be breaking the law.

And for projects that need to be notified to the HSE, you will be asked how much time has been allocated when you submit the F10 notification form online.

Why you need a planning period

Research by the HSE has shown that unrealistic deadlines are a large contributor to the level of risk on site. This is why the CDM regulations require the allocation of time to plan the work, and why when a construction project is notified to the HSE, they will ask for details of the planning period.

  1. What is the time allocated by the client under regulation 4(1) for the construction work (in weeks, including all planning and preparation, as well as the construction phase)?

Common sense would agree with this argument, if you rush into carrying out an activity, you may not have enough time to adequately assess the risks. You may also not have enough time to adequately assess the competence of the person you are appointing to carry out the role. They, in turn, may not have enough time to carry out any training or inductions required, or resourcing the required staff and equipment correctly.

Planning is the key to minimising risks, and in a high-risk construction environment, failure to minimise risk can have severe consequences.

Each team member needs to have the resources and time to plan the work properly. If members of the team are appointed early enough they can contribute to risk reduction.

At the design stage, the principal designer needs time to carry out their duties and to assist designers by discussing areas of the design with health and safety implications. Contractors can contribute to discussions on the buildability of the project and the maintainability of the finished structure.

designer planning

These discussions can improve project success by eliminating problems that may have not been identified until halfway through the construction had the time not been given for this collaborative approach.

When appointing project team members (principal designer, principal contractor, designers and contractors), the client needs to consider the resources and time needed to plan and do the work properly.

The principal designer will need sufficient time after the appointment, but before project commencement, to carry out their duties under the regulations. Designers will also need time to carry out their own CDM imposed duties and ensure they have adequately assessed the health and safety aspects of the design work.

The principal contractor needs time to plan the work, review the pre-construction information and develop the construction phase plan before work starting on site. This will include raising any queries, organising welfare facilities, and making sure they have all the information they need to manage the project safely on site.

Contractors should also be given sufficient time to allow them to plan the work and make the necessary preparations for site commencement. This will include mobilising the plant, equipment and staff required for the project.

How much time do you need?

But how much time is required? 4 weeks? 6 weeks? 2 months? 6 months? There is no one size fits all approach when it comes to the planning period for construction projects. If there was, the regulations would state it.

Every construction project is different, in size, complexity, duration, team and amount of work involved. More complex or larger projects are going to need a longer planning period so that all of the issues, hazards and risks are properly considered. Your team will still need time to plan and prepare on smaller, simpler projects, but the process is often more straightforward and you won't need as long.

planning on a calendar

While the client is responsible for the allocation of sufficient time, they are not expected to be an expert in the construction process. The client should consult with those they are appointing to get a good idea of the time they will need for planning and preparation. All parties can agree on a suitable time period.

These discussions should take place as early as possible in the initial project planning stages as clients must inform those they are appointing (principal designer, principal contractor, designers and contractors) of the time they are allowing for planning and preparation before the work starts.

The principal designer has a duty to assist the client in their duties and should be in a better position to advise on whether the timeframes being discussed are practical and reasonable for the project.

Although allowing a sufficient planning period for each stage of the project is a CDM imposed duty, this shouldn’t be just seen as a safety requirement. Good planning is the key to the smooth running and success of any project helping you reduce costs, and headaches, in the construction phase.

Good planning means better control of costs, deadlines, and safety too.


Still unsure or need help with CDM on your project? Our free step-by-step CDM duty holder guides can help you with your duties.

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This article was written by Emma at HASpod. Emma has over 10 years experience in health and safety and BSc (Hons) Construction Management. She is NEBOSH qualified and Tech IOSH.

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