Space gives you resilience
In LVAC installations, room design is every bit as important as the equipment itself. A well-positioned board in a well-designed room will be safer, easier to maintain, and more reliable over its lifetime. A poorly planned space, on the other hand, can make safe work difficult or impossible.
Unfortunately, it’s common to see plant rooms where equipment is crammed in to save space. While it may look efficient on a drawing, it creates a cramped, unsafe, and unmaintainable environment, not to mention the additional heat, dust, or other environmental influences from other equipment in the same room.
Real-World Clearance Rules We Use
We work to space allowances that go beyond the legal minimums, ensuring the room is safe for both operation and maintenance. When supplying a board, we aim to present best practice: if you can allow the space, do so. Providing generous clearances gives the client a safer, more adaptable, and easier-to-maintain installation in the long term.
While real-world constraints may sometimes dictate otherwise, building designers should be fully aware of the infrastructure requirements from the outset. Designing with these allowances in mind from day one avoids compromises later and ensures the electrical room remains fit for purpose throughout its life.
Front-Access Boards
We allow 750 mm clearance on each side to permit safe removal of side panels where necessary. This also improves manoeuvrability for tools and equipment and provides a natural airflow path around the enclosure. Even where a board can technically be installed close to a wall and serviced entirely from the front, a little extra side clearance pays off over the life of the installation.
Better side access improves visibility of cable terminations, makes modifications easier, and encourages passive cooling — a valuable safeguard if the board is in an outdoor enclosure or a plant room with HVAC control. If environmental control fails, additional open space helps reduce heat build-up and can keep equipment within safe limits.
For these reasons, side clearance is regarded as good engineering practice and is incorporated wherever possible in our designs. Just to put things into perspective below shows an employee kneeling to remove a side panel.
Rear-Access Boards
We allow 1 metre clearance at both front and rear. This ensures access to every panel and breaker, supports safe working positions, and allows room for test equipment and tools. Keep in mind that if you have a rear-access board, the user must physically remove the rear plate and stand in place to service connections, 1 metre is the absolute minimum.
Question: In an emergency, would you really want to tend to a person in a 1 metre walkway?
ACB Carriers – Always provide enough unobstructed floor space in front to fully extend air circuit breaker carriers for inspection, servicing, or replacement. For removal, also consider the lift truck and its turn radius for moving the equipment out of the area. Many customers have spares and swap them during outages to reduce wear on the installed unit.
Door Swing & Personnel Space – Doors must be able to open fully without obstruction from walls, ducts, or other plant. Even with doors open, there must still be room for personnel to stand and work comfortably.
Heating & Ventilation – Keep heat sources clear of working areas in front of the board. Good ventilation and air circulation not only protect equipment from overheating but also make the space safer and more comfortable for operators.
What the Law and Guidance Say About Space Allowances
CDM 2015 (Construction Design and Management Regulations)
Requires “suitable and sufficient safe access and egress” and “sufficient working space” for the work to be carried out safely. No fixed measurements are given, it’s the designer’s responsibility to define and justify clearances that allow safe operation and maintenance. These requirements must be addressed from the design stage and documented in the pre-construction information, the Construction Phase Plan, and the Health and Safety File.
HSE Overview: https://www.hse.gov.uk/construction/cdm/2015/index.htm
Full Legislation: https://www.legislation.gov.uk/uksi/2015/51/contents/made
HSE Legal Guidance (L153): https://www.hse.gov.uk/pubns/priced/l153.pdf
EAWR – Electricity at work act 1989
EAWR is Regulation 15: Working space, access and lighting, which directly addresses adequate working space at electrical equipment.
The formal legal wording from the HSE’s HSR25 guidance document (the Memorandum of guidance on the Electricity at Work Regulations 1989) states:
Regulation 15 – Working space, access and lighting
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“For the purposes of enabling injury to be prevented, adequate working space, adequate means of access, and adequate lighting shall be provided at all electrical equipment on which or near which work is being done in circumstances which may give rise to danger.”
Reference: https://www.hse.gov.uk/pubns/books/hsr25.htm
HSE Guidance (HSG85) – Electricity at Work: Safe Working Practices
HSG85 underscores that “adequate working space”, safe access, and adequate lighting must be provided around switchboards to support safe operation, isolation, inspection, maintenance, and potential replacement, even when all live parts are enclosed
HSG85 reinforces that exact clearances should be established through risk-based design, not just as a minimum to meet installation requirements. Much like how we quote minimum 750 and 1 meter distance.
Reference: https://www.hse.gov.uk/pubns/books/hsg85.htm
Hard and Fast Rules?
Hard and Fast Rules?
There are no set millimetre or metre figures in CDM, HSE, or the Electricity at Work Regulations for LVAC board access. The law works on the principle of “suitable and sufficient” space, meaning you must design with realistic, risk-based clearances. Our 750 mm / 1 metre rule for side, rear, and front clearance, combined with space for ACB carriers, door swing, and free airflow, is how we ensure designs remain safe and potentially future-proof.
The False Economy of Small Rooms
Cramming boards into undersized rooms may save a few square metres at the build stage, but it increases accident risk, slows or prevents essential maintenance, shortens equipment life through heat build-up and restricted airflow, and limits future expansion.
In tightly packed rooms, you become completely reliant on HVAC to keep temperatures safe. If those systems fail while the board is running at 85–90% load around the clock, you could face a rapid and dangerous temperature rise. Designing for passive airflow as well as forced cooling buys time in a failure scenario and reduces everyday HVAC workload.
Extra clearance is not wasted space, it’s a safety buffer that improves resilience, helps control temperature naturally, and makes the room more adaptable for the decades the equipment will be in service.
Wrapping it Up
Design every LVAC room as though you’ll be the one working in it years from now. If you can imagine changing a breaker, pulling cables, or carrying out an emergency isolation without moving other equipment or working in unsafe positions, the design is on track. If not, it’s time to revisit the layout.
Disclaimer:
The information provided on this site is for general informational purposes only and may not reflect the most current regulations or standards. Legislation, industry guidelines, and best practices can change over time, and it is the user’s responsibility to research and ensure compliance with the latest requirements for their specific situation. Always consult a qualified professional for advice tailored to your project or application.