You may associate Construction Phase Plans with major developments, commercial sites and projects involving large numbers of contractors.
But even if you’re building an extension, carrying out a loft conversion or working on another relatively small domestic project, a Construction Phase Plan is still required.
Under the Construction (Design and Management) Regulations 2015, a Construction Phase Plan is required for every construction project. And a recent HSE prosecution has provided a timely reminder that domestic builders are very much included.
A £10,000 reminder from HSE
In August 2026, HSE reported the prosecution of a Yorkshire building company following work on a domestic extension in Bradford.
The extension had been constructed over existing gas service pipework and the flue from the homeowner’s working boiler had effectively been enclosed within the new extension.
The situation was subsequently classed as immediately dangerous. The gas supply was disconnected, leaving the homeowner and her children without gas for several weeks, and around £4,000 of remedial work was required.
During its investigation, HSE also found that the company director was unable to demonstrate that construction phase plans had been prepared for the company’s building work — despite the business working exclusively for domestic customers.
HSE served an Improvement Notice requiring the company to establish a system for producing written Construction Phase Plans where it acted as principal contractor. The company then failed to comply with the notice.
The company was ultimately fined £10,000, with additional costs. The director was also personally fined.
The message from the HSE inspector involved was particularly clear: everyone controlling domestic building work needs to make sure that a suitable and sufficient Construction Phase Plan is in place before building work starts.
The Construction Phase Plan isn’t just paperwork
It is worth looking beyond the prosecution itself.
A Construction Phase Plan isn’t intended to be a document that gets produced simply so you can say you have one.
Its purpose is to make you think about how the work will actually be carried out safely.
- What are the significant risks on this particular project?
- Who will be working on site?
- How will different trades work alongside each other?
- Are there existing services that need to be considered?
- What arrangements are required for access, welfare, emergencies and site security?
- What risks are created by the sequence of work?
These are practical building questions, not admin ones.
In the Bradford case, the HSE highlighted a failure to properly plan for the existing gas pipework and boiler flue. The consequences could have included gas leaks, fire, explosion or carbon monoxide poisoning.
That’s exactly why planning health and safety before work begins matters.
“But it’s only a small job”
This is perhaps the most important misconception for smaller residential builders.
HSE’s own Construction Phase Plan guidance specifically refers to builders and tradespeople carrying out everyday projects including kitchens and bathrooms, structural alterations, roofing work, dormers, extensions and loft conversions.
If you’re the only contractor, or you’re acting as principal contractor, you can be responsible for preparing the plan.
But that doesn’t mean every rear extension requires a huge health and safety document.
HSE says that the plan should be proportionate to the project. For straightforward work, a simple plan may be enough to demonstrate that you have properly considered health and safety before starting.
That’s an important distinction.
Small job doesn’t mean no plan.
It means an appropriately detailed plan.
What should a Construction Phase Plan cover?
The precise content depends on the nature and risk of the project, but typically the plan should establish how health and safety will be managed during construction.
That could include:
- details of the project and the people involved
- significant risks specific to the job
- site rules and arrangements
- coordination between contractors and trades
- site inductions
- welfare arrangements
- emergency procedures
- arrangements for controlling particular risks during the work.
Most importantly, it needs to reflect the actual project.
Simply recycling a generic document from one job to another isn’t the point. A loft conversion, structural alteration, extension and new-build house can each present very different risks.
Get the plan in place before you start
The clue is in the name: this is the construction phase plan, but it needs to be prepared before that phase begins.
That’s when you have the opportunity to identify potential problems rather than reacting to them once people, materials and machinery are already on site.
And there is a commercial benefit as well as a compliance one.
Good planning can help you spot clashes, organise trades, identify unusual risks and establish responsibilities before they become expensive problems.
Health and safety planning should be part of professional project preparation – alongside estimating the job, planning the work and ordering materials.
Health & Safety Xpert takes away the blank-sheet problem
For smaller building companies, the difficulty is often not understanding that health and safety matters.
It’s finding the time to produce the documentation properly when you’re also quoting, buying materials, answering customers, organising subcontractors and running jobs.
HBXL’s Health & Safety Xpert is designed specifically to make that process easier for builders.
It automatically produces the Construction Phase Health & Safety Plan along with the other documentation required to manage health and safety across your projects, including risk assessments, COSHH assessments, method statements, Pre-Construction Information and site management documents.
For smaller projects, Health & Safety Xpert also includes a Simple Construction Phase Plan, based on HSE’s CIS80 guidance, so the paperwork can remain proportionate to the scale and risks of the work rather than becoming an unnecessary administrative exercise.
And if you already use HBXL’s EstimatorXpress, project information can be brought into Health & Safety Xpert, helping the software identify relevant health and safety documentation for the particular job – automatically.
Don’t wait for an HSE inspector to ask
The recent prosecution reinforces something that residential builders cannot afford to overlook.
A domestic customer doesn’t make a project exempt.
A small job doesn’t make a Construction Phase Plan optional.
And discovering that your paperwork isn’t in order after something has gone wrong is far too late.
Put the plan in place before work starts, make it relevant to the project and use it as part of the way you actually manage the job.
That’s better for your customer, better for the people working on site – and considerably better for your business.
What next?
Try Health & Safety Xpert for 14 days. No obligation. Or choose a date and time for a quick demo.
