> Disclaimer: SiteKiln gives you plain-English information, not legal or health and safety advice. Always follow your site-specific risk assessments and talk to a qualified professional.
The short version
CDM 2015 Part 4 says demolition and dismantling must be planned and carried out in a way that prevents danger, or where that's not practicable, reduces it as far as possible.
BS 6187 then sets the industry standard: do a proper structural appraisal, choose a safe method and sequence, use competent people, create exclusion zones, and avoid uncontrolled collapse.
What CDM 2015 actually says about demolition
Part 4, Regulation 20 of CDM 2015 states:
Demolition or dismantling must be planned and carried out in such a manner as to prevent danger, or where that's not practicable, to reduce danger to the lowest level reasonably practicable.
- The plan should specify how the work will be done, including the sequence to prevent accidental collapse.
HSE's demolition guidance adds:
- Demolition arrangements should be written down before work begins -- usually as a method statement or demolition plan with a clear sequence.
- You must identify safe working areas, exclusion zones and debris zones, and maintain them as the job progresses.
- A sequence must be adopted that eliminates the possibility of uncontrolled collapse -- removing non-critical elements first, and working towards stiffer elements like braced cores.
So legally, "just get the machine in and see how we go" is out; written planning and controlled sequence are in.
BS 6187 -- what "good practice" looks like
BS 6187:2011 is the British Standard code of practice for full and partial demolition.
It sets out good practice for:
Planning and risk assessment
- Structural investigation and appraisal of the building/structure -- its age, construction, history and alterations.
- Identification of hazards -- structural (stability, progressive collapse), health (asbestos, dust, lead), services (gas, electric), neighbouring buildings, public interfaces.
Demolition method and sequence
- Selecting suitable methods (e.g. top-down, high-reach, deliberate collapse, deconstruction) based on structure, surroundings and risk.
- Detailed sequence to maintain stability and avoid unplanned collapse.
Structural stability and temporary works
- Maintaining stability during demolition, including using temporary structures for stability, support and access where needed.
Safe zones and protection
- Establishing and managing exclusion zones, safe working spaces and debris zones, sized to the method and site constraints.
- Protecting workers, the public and nearby buildings.
BS 6187 isn't law, but HSE and the courts treat it as the benchmark for "what a competent demolition contractor should be doing".
Who is legally on the hook
CDM and BS 6187 together put responsibility across the team -- but if you're running the job, a lot lands on you:
Client:
- Must appoint competent designers and contractors and allow enough time and resources for safe demolition planning and work.
Principal designer (for projects with more than one contractor):
- Must plan, manage and monitor health and safety in the pre-construction phase, including ensuring key information (surveys, structural info, asbestos, services) is available for demolition planning.
Principal contractor:
- Once demolition starts, must plan, manage and monitor the demolition work and coordinate contractors so it is carried out safely.
- This includes ensuring there is a demolition plan/method statement, exclusion zones, sequencing, supervision and competent operatives.
Demolition contractor / site management:
- Must follow BS 6187-style principles: carry out and follow the plan, maintain stability, adjust zones and sequences as conditions change, and supervise workers.
If you are a small builder doing anything beyond very minor strip-out, you're expected to recognise when you're into "demolition" territory and either step up to this standard or bring in a specialist.
What you should never skip before demolition
For any demolition or heavy strip-out job, you should expect to see, in writing:
A structural appraisal
- What's holding the building up, where weaknesses are, how alterations and age affect stability, and what happens when you remove key elements or load floors with plant/debris.
A survey for hazardous materials
- Asbestos and other dangerous materials identified and removed/managed before you start knocking things about.
A demolition plan/method statement
- Method and sequence of demolition.
- Plant and techniques to be used (hand, machine, high-reach, deliberate collapse).
- Temporary works and stability measures.
- Exclusion and debris zones; protection for neighbours and the public.
- Waste handling and site clearance.
Service isolation and making safe
- Gas, electricity, water, telecoms isolated or clearly controlled before work that could damage them.
If those basics aren't in place, you're relying on luck rather than meeting CDM and BS 6187 expectations.
You don't have to be an NFDC big gun to do this well, but you do need a written plan, a stable structure at every stage, and a clear idea of who's responsible for what, or you're flying blind.
What to do next
- Before your next demolition or heavy strip-out, make sure you have a written demolition plan with a clear sequence -- "just get the machine in" is not a plan.
- Get a structural appraisal from a competent engineer before knocking anything about, especially on older or altered buildings.
- Check for asbestos and other hazardous materials before you start -- a survey is always cheaper than an incident.
- Confirm that gas, electric, water and telecoms are isolated before any demolition work begins.
- If the job is beyond simple strip-out, bring in a specialist demolition contractor rather than winging it.
Sources
- Construction (Design and Management) Regulations 2015 -- Part 4, Regulation 20: demolition/dismantling must be planned to prevent danger.
- Health and Safety at Work etc. Act 1974 -- general duties.
- Control of Asbestos Regulations 2012 -- duty to manage asbestos before demolition.
- BS 6187:2011 -- Code of practice for full and partial demolition.
- HSE -- Demolition and structural stability guidance.
Disclaimer
This guide is general information for small UK construction businesses and trades, not formal legal or structural engineering advice.
SiteKiln is not a law firm and this page is not a substitute for getting advice on your specific situation.
Health and safety law, CDM and industry standards including BS 6187 are updated from time to time, and how they apply will always depend on the exact facts on your project and your role.
If you're dealing with demolition planning, a structural stability concern, enforcement notice or complex demolition project, get specific advice from a competent structural engineer, demolition specialist and/or solicitor before you make big decisions.
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