UK Construction H&S Guide: CDM 2015, WAHR & RIDDOR

Quick Answer: UK construction site health and safety is governed by the Health and Safety at Work etc Act 1974, the Construction (Design and Management) Regulations 2015 (CDM 2015), and a stack of topic-specific rules covering work at height, hazardous substances, noise, manual handling and PPE. Every job, from a loft conversion to a new build, sits under CDM 2015, and the duty holders (client, principal designer, principal contractor, contractor) all have legal obligations even when there's only one person on site. This guide tells you which regulations apply, what you actually have to do, and where to read the detail.

What this guide covers

This is a hub for UK tradespeople trying to work out what health and safety actually requires of them. Not what a consultant would write in a glossy management system, but what a sole trader, a small firm or a sub-contractor on a domestic refurb needs to do to stay on the right side of the Health and Safety Executive (HSE) and not end up in court after an incident.

The legal framework is broader than most people realise. The Health and Safety at Work etc Act 1974 sits at the top and creates the general duty to protect workers and anyone affected by the work. Underneath it sits CDM 2015 (the regulations that apply to almost every construction project in Great Britain) plus topic regulations covering specific risks: falls, asbestos, COSHH, noise, vibration, manual handling, PPE and so on. Most cover both employers and the self-employed, and most apply to domestic clients as well as commercial ones.

What follows walks through the main risk areas and links out to the detailed articles in our knowledge base. If you're after the practical checklist for a specific job, the deeper articles cover the kit, the readings, the limits and the paperwork. If you're trying to work out which regulations apply to your project at all, start here and follow the links.

CDM 2015 and the duty holder system

CDM 2015 applies to all construction work in Great Britain, full stop. There's no minimum project size, no domestic exemption, no "it's only a small job" carve out. What changes with project size is the notification threshold (HSE must be notified for projects over 30 days with more than 20 workers at any point, or more than 500 person-days) and whether you need a written construction phase plan (always, but it scales with project complexity).

The four duty holder roles are client, principal designer, principal contractor and contractor. On a domestic project the client's duties transfer to the contractor (or the principal contractor if there's more than one contractor on site). CDM Regulation 7 sets the trigger for principal appointments: as soon as more than one contractor is working on the project, the client must appoint a principal designer and a principal contractor in writing. Miss that and the client carries the duty themselves. For the practical detail on how the roles fit together with welfare, briefings and paperwork, read the small site setup guide and the CDM 2015 welfare facilities requirements.

Before anyone starts work on site, the principal contractor must run an induction. A proper site induction checklist covers project specifics, hazards, welfare locations, emergency procedures, permit systems and the names of the first aiders. On longer jobs the induction is supplemented by regular toolbox talks under CDM 2015, which are short briefings on a single topic recorded in writing (usually the operative signs the sheet). Talks aren't a substitute for written risk assessments, but they're how you actually keep risk awareness alive on site.

The other CDM document you can't skip is the risk assessment and method statement (RAMS) for each significant task. The method statement guide covers how to structure a RAMS that's useful rather than boilerplate: hazards, controls, sequence of work, PPE, plant, emergency procedures and the named competent person. Generic RAMS downloaded off a template site won't help you if HSE turns up; the document has to reflect the actual job, the actual site and the actual people.

Work at height and falls from height

Falls from height remain the single biggest killer in UK construction. The Work at Height Regulations 2005 (WAHR 2005) apply to any work where a person could fall a distance liable to cause personal injury. There is no minimum height, despite the persistent myth of a "two metre rule" (that was scrapped years ago). If you can fall and hurt yourself, WAHR 2005 applies.

Regulation 6 of WAHR 2005 sets the hierarchy of control: avoid work at height where reasonably practicable, then prevent falls using collective measures (guardrails, scaffolds, MEWPs), then minimise the distance and consequences of a fall (nets, airbags), with personal fall arrest as the last resort. Schedule 2 to WAHR 2005 covers the design and inspection requirements for scaffolding. Any scaffold over two metres in working platform height must be inspected before first use, after any alteration, after any event likely to affect stability, and at intervals not exceeding seven days. See the scaffold inspection requirements guide for what the inspection actually involves and how to log it under TG20 / TG30.

The other big work-at-height area is general access: ladders, stepladders, MEWPs, tower scaffolds. The Work at Height Regulations 2005 safety guide covers when each is appropriate, the duty holder structure, and how to assess a task against the hierarchy. The shorter reference at working at height regulations summarises the legal duties for quick lookup.

If you're working on a roof, near an excavation edge, or anywhere a fall could be over two metres, collective protection (edge protection, guardrails, scaffolds) is the default. Harness-based fall arrest is only justified when collective measures aren't reasonably practicable, and a harness alone isn't fall arrest, it's part of a system that includes a suitable anchor, an energy-absorbing lanyard, and crucially a rescue plan. Without a rescue plan a person suspended in a harness can be dead from suspension trauma in under 30 minutes.

Hazardous substances: asbestos, silica, dust and COSHH

The Control of Substances Hazardous to Health Regulations 2002 (COSHH 2002) cover most chemical and dust exposures. They require an assessment, control, monitoring, health surveillance where appropriate, and training. The COSHH regulations guide for tradespeople explains the basic structure, and the COSHH assessment guide takes you through how to write one for a real task without producing twenty pages of unread paperwork.

Asbestos sits under its own regime. The Control of Asbestos Regulations 2012 (CAR 2012) apply to any work that might disturb asbestos-containing materials (ACMs), and that includes most domestic refurbs on properties built before 2000. Before any refurbishment or demolition, the duty holder must arrange a refurbishment and demolition (R&D) survey. The asbestos awareness guide covers identification, where ACMs are commonly found, and what to do if you suspect you've disturbed one. The asbestos bulk sampling procedure covers the CAR 2012 sampling technique for licensed and non-licensed work. Any work on licensable asbestos (most sprayed coatings, insulation, board over a certain condition) requires an HSE-licensed contractor; do not touch it.

Silica is the other big dust hazard. Cutting, grinding or breaking concrete, brick, mortar, sandstone, granite or tiles produces respirable crystalline silica (RCS). The UK workplace exposure limit (WEL) for RCS is 0.1 mg/m³ averaged over 8 hours, set by HSE under COSHH 2002. The respirable crystalline silica controls guide covers the science and the WELs in detail, and the on-site dust control guide covers the practical kit: on-tool extraction (M-class minimum), water suppression, RPE with the right assigned protection factor (APF), and the face-fit testing requirement for any tight-fitting mask.

Lead is still a real risk on older properties. Pre-1992 paintwork may contain lead. The lead paint testing guide covers swab kits versus XRF analysers, and the working with lead paint guide covers RPE selection, containment and the Control of Lead at Work Regulations 2002. For skin contact hazards (most common cause: cement burns and dermatitis from wet cement), the cement dermatitis and skin protection guide covers the COSHH controls and PPE.

Noise, vibration and physical agents

The Control of Noise at Work Regulations 2005 set two action values and an exposure limit. The lower exposure action value is a daily personal exposure of 80 dB(A) (or peak 135 dB(C)); above this you must provide hearing protection on request and information and training. The upper action value is 85 dB(A) (peak 137 dB(C)); above this hearing protection becomes mandatory, the area must be marked as a hearing protection zone, and health surveillance is required. The exposure limit value is 87 dB(A) (peak 140 dB(C)) accounting for the attenuation of hearing protection. The detailed practical guide is at noise at work regulations 2005 action levels, with the quick reference at control of noise at work regulations 2005 limits and a separate summary at noise at work regulations.

Hand-arm vibration from power tools causes hand-arm vibration syndrome (HAVS), a permanent and disabling condition. The Control of Vibration at Work Regulations 2005 set an Exposure Action Value (EAV) of 2.5 m/s² A(8) and an Exposure Limit Value (ELV) of 5 m/s² A(8). Most trade tools (breakers, grinders, SDS drills, needle guns) will hit the EAV in under an hour and the ELV in under four. The hand-arm vibration syndrome points system guide covers the HSE points calculator, and the HAVS UK limits and control guide covers health surveillance triggers and the symptoms to watch for. The noise at work exposure limits guide cross-references both regimes.

Manual handling injuries are still the single largest cause of lost time in construction. The Manual Handling Operations Regulations 1992 (MHOR 1992) require avoidance, assessment and reduction in that order, and there are no fixed weight limits in the regulations (the HSE guidance figures of 25 kg for men and 16 kg for women are not legal limits but assessment thresholds). Read the MHOR 1992 risk assessment guide for the TILE/TILEO framework (Task, Individual, Load, Environment, Other factors) and the manual handling regulations reference for the quick legal summary.

Electrical, excavation and other site hazards

Electrical work on UK construction sites is governed by the Electricity at Work Regulations 1989 and BS 7671 (the IET Wiring Regulations, currently 18th Edition). On site, the convention is 110V centre-tapped earth (CTE) for portable tools, supplied via a transformer, with mains 230V kept for site offices and welfare. The electrical safety on site guide covers the 110V system, RCD protection, PAT testing intervals for site tools (typically three-monthly for 110V and one-monthly for damaged tools), and how to handle live work decisions.

Excavations below 1.2 metres need support or battering back to a safe angle, and HSE expects a competent person to inspect at the start of every shift and after any event likely to affect stability. The excavation safety guide covers shoring, trench boxes, the CDM notification thresholds for deep excavations and the access requirements. Before any excavation, you need to know what's underground. The avoiding underground utility strikes guide covers HSG47 (HSE's guidance on avoiding services), CAT and Genny scanning procedure, and how to interpret utility records.

Confined spaces (any space substantially enclosed where there's a foreseeable risk of serious injury from hazardous substances or conditions) are covered by the Confined Spaces Regulations 1997. Entry requires a safe system of work, usually a permit, gas monitoring, and a workable rescue plan that doesn't rely on the fire and rescue service. The confined space regulations 1997 permits and rescue guide covers the practical procedure, and the confined spaces regulations reference summarises the legal duties.

Fire safety on site is covered by the Regulatory Reform (Fire Safety) Order 2005 and HSG168 (HSE's fire safety in construction guidance). The construction site fire safety guide covers BS 5839-1 detection requirements, escape routes, hot works controls and means of raising the alarm. Any hot work (welding, grinding, soldering, torch-on roofing) needs a hot works permit with a designated fire watch, typically 60 minutes after work finishes for torch-on or 30 minutes for general hot works.

Traffic management around construction sites and on the highway is governed by Chapter 8 of the Traffic Signs Manual. Any work that obstructs the carriageway or footway needs a TM plan and usually a permit from the local highway authority. The traffic management Chapter 8 guide covers the basic taper, buffer and works zone layouts and when you need NRSWA accreditation.

PPE, RIDDOR and the people side

The Personal Protective Equipment Regulations 2002, amended by the PPE at Work (Amendment) Regulations 2022, require employers to provide suitable PPE free of charge. The 2022 amendment extended the duty to "limb (b) workers" (effectively most casual or sub-contracted workers, not just employees), so the practical position is that anyone you direct on site should be getting PPE without paying for it. The PPE requirements by trade guide covers the trade-by-trade specification (head, eye, hearing, foot, respiratory, hand, hi-vis), and the PPE selection guide covers how to match the PPE to the actual hazard rather than defaulting to "the kit we always wear".

Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR 2013) require reporting to HSE for: any fatal or specified injury, any injury causing more than 7 days' absence from normal work (calendar days, including weekends, excluding the day of the accident), certain occupational diseases (including HAVS, occupational asthma and dermatitis), and any dangerous occurrence on the schedule (scaffold collapse, biological agent release, certain plant failures). The self-employed must report when injured on someone else's premises. Reports are made online via the HSE RIDDOR portal within 10 days for over-7-day injuries and immediately by telephone for fatals.

Lone working on a construction site is common for sole traders and small firms. There's no specific lone working regulation, but the Management of Health and Safety at Work Regulations 1999 requires a suitable and sufficient risk assessment, and certain tasks (confined spaces, live electrical work, asbestos work) effectively prohibit lone working. The lone worker safety guide covers the legal duties, the check-in protocols and the dead-man devices available, with a sister piece at lone working in construction health and safety requirements.

A few specific people-risks worth flagging. Working in hot conditions is increasingly relevant in UK summers, and there's no maximum site temperature in UK law (despite the persistent myth), but the duty under the Workplace (Health, Safety and Welfare) Regulations 1992 is "reasonable" temperature, which on a hot day means rest breaks, water and shade. Weil's disease for plumbers (leptospirosis) is a real risk for anyone working in drains, sewers or near standing water (rat urine is the vector). Site security under BS 7818 and tool protection isn't strictly H&S but it overlaps with site hazards (unsecured sites attract trespass and the resulting injuries).

Common questions

Do CDM 2015 regulations apply to a domestic job?

Yes. CDM 2015 applies to all construction work in Great Britain. On a domestic project the client's duties transfer to the contractor, or to the principal contractor if there's more than one contractor on site (CDM Regulation 7). The domestic exemption that existed under CDM 2007 was removed in the 2015 update.

When do I need to notify HSE under CDM 2015?

You must notify HSE (form F10) when the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, OR exceed 500 person-days in total. The duty to notify sits with the client. Notification is free and done online.

Is there a legal minimum height for work at height regulations to apply?

No. WAHR 2005 applies to any work where a person could fall a distance liable to cause personal injury. The "two metre rule" was scrapped in 2005. A fall from a step ladder onto a hard floor can kill, and WAHR 2005 covers it.

What's the difference between an action value and a limit value for noise?

Action values are exposure levels that trigger employer duties (provide hearing protection, training, signage, health surveillance). Limit values are absolute ceilings on personal exposure that account for the attenuation provided by hearing protection. The Control of Noise at Work Regulations 2005 set the lower action at 80 dB(A), the upper action at 85 dB(A), and the limit at 87 dB(A) all as daily personal exposure A(8).

Do I have to report a near miss under RIDDOR?

Only if it's a "dangerous occurrence" listed in Schedule 2 to RIDDOR 2013 (for example, scaffold collapse over five metres, certain plant failures, biological agent release). Generic near misses are not reportable to HSE under RIDDOR 2013, but your own incident reporting system should still capture them.

Where to start

  1. Identify the duty holder structure for your project. Who is the client, the principal designer, the principal contractor and the contractor(s)? On a domestic refurb with one contractor, you carry the client duties. Get that clear before anything else.

  2. Write a construction phase plan. Even on a single-day domestic job, CDM 2015 requires a written plan proportionate to the risks. It doesn't have to be long, but it has to cover the site setup, the hazards, the controls, the welfare and the emergency procedures. The small site setup guide has a workable template.

  3. Do the task-specific risk assessments. For each significant task (work at height, hot works, asbestos disturbance, deep excavation, confined space entry, high-noise activity) write a RAMS using the method statement guide and brief everyone on site before work starts.

  4. Sort welfare and first aid before the first day. Toilet, washing, drying, hot drinks, somewhere to sit and eat. On any site lasting more than a few days these are mandatory under CDM Schedule 2 and the CDM 2015 welfare facilities guide.

  5. Brief, induct and record. Run a site induction on day one using the site induction checklist, then run toolbox talks under CDM 2015 weekly on whatever hazard is most live that week. Keep the signed sheets.

Regulations and standards summary