There is no universal gap for all commercial-kitchen equipment: the layout must satisfy the exact manufacturer's clearances plus cleaning, door movement, service access and safe withdrawal.
Installation boundary: This article explains design and coordination principles. Drainage, ventilation, fire, electrical and fabrication work must be designed and carried out by competent people using current project documents, manufacturer instructions and the requirements that apply in the relevant UK nation.
The short answer
Use the current installation manual for each model, then overlay four envelopes: operational space, ventilation and heat clearance, cleaning access, and maintenance/removal space. A manufacturer may permit close side-by-side installation but still require top, rear or service-side access. If equipment is sealed to a plinth or wall, the junction must prevent dirt entry and remain maintainable; if it is mobile, all utilities must be designed for movement and protected from strain.
Draw envelopes, not just rectangles
Show open oven and dishwasher doors, loading trolleys, fryer basket lift, filter removal, fridge condenser airflow, control-panel swing and the technician's access to service covers. A 900 mm-wide machine can require much more than a 900 mm bay. Opposing doors and drawers can block each other even when individual clearances are met.
The cookline also needs safe human movement. Staff should not step backward from hot oil into an open oven door or squeeze past a dishwasher hood. Consider hot-handle reach, tray transfer and temporary landing space. These operational clearances are separate from statutory escape-route and accessibility design, which must also be coordinated.
Fixed, plinth-mounted or mobile are different strategies
A fixed appliance can be sealed to adjacent fabrication or mounted on a correctly detailed plinth to eliminate an uncleanable void. That requires accurate service access, ventilation and replacement planning. A small gap that cannot admit cleaning tools is usually worse than either a properly sealed junction or a genuinely cleanable clearance.
Mobile equipment can improve cleaning, but flexible gas, water, waste and electrical connections must be specifically designed for movement. Castors need brakes and a stable floor; hoses and cables need restraints and safe routes. Gas-appliance movement and reconnection must be handled within the manufacturer's instructions and by people with the appropriate commercial catering competence.
What common failures reveal
| Site symptom | Likely installation issue | Practical consequence |
|---|---|---|
| Refrigerator overheats | Ventilation grille blocked by wall or adjacent unit | High energy use and compressor failure |
| Engineer removes worktop to service oven | Service panel clearance not plotted | Long downtime and damaged fabrication |
| Food collects in 25 mm gap | Space too narrow to clean and not sealed | Pest and hygiene risk |
| Door strikes opposing appliance | Open envelopes omitted from layout | Unsafe workflow and damaged hinges |
| Hose tears when unit moves | Mobile strategy without utility length and restraint design | Leak, shock or gas risk |
Installation and coordination checklist
- Obtain clearance and service diagrams for each exact model.
- Draw doors, drawers, filters, panels, trays and trolley movement fully open.
- Protect ventilation inlets, exhausts and hot-surface clearances.
- Choose cleanable clearance or a properly sealed fixed junction—avoid dead gaps.
- Reserve a safe withdrawal and replacement route for major equipment.
- Design castors, brakes, restraints and flexible services as one mobile system.
- Coordinate staff workflow, landing space and adjacent hot operations.
- Prove access during commissioning before infills are permanently fixed.
Commissioning and handover
Keep manufacturer clearance drawings with the final layout and identify panels that must remain accessible. Demonstrate normal cleaning and one representative equipment withdrawal. Record any infill or plinth panel that must be removed first. Future storage, shelving or replacement equipment should not occupy the documented service envelope without review.
Questions to ask before approving the work
- Which clearance comes from the exact manufacturer?
- Can staff clean every surrounding surface?
- Can every service panel and filter be removed?
- How will the equipment leave the room for replacement?
- Are mobile utilities restrained and rated for repeated movement?
Capture the installation detail before it becomes a site problem
Plan the full kitchen installation across equipment, utilities, ventilation, safety, hygiene and handover.
Technical sources and further reading
- Assimilated Regulation (EC) No 852/2004, Annex II
- Food Standards Agency: Getting ready to start a food business
- HSE: Provision and Use of Work Equipment Regulations overview
- RATIONAL: Documents and appliance instructions
Last technical review: 14 August 2026. Always check the latest manufacturer instructions, statutory guidance, standards and project approvals before installation.