How to Design a Commercial Kitchen From the Ground Up

Seven steps to a kitchen that works

Work through these in order. Each decision narrows the next, so the sequence matters as much as the detail.

1. Start with the menu and the covers. Everything downstream - power, gas load, extraction volume, floor area - is driven by what you cook and how many you feed at peak. A high-output grill and wok section needs far heavier extraction than a sandwich and salad operation, so pin the menu and realistic peak covers down before you draw a single line.
2. Map the workflow before the equipment. A well-planned kitchen follows the food in one direction: delivery, storage, preparation, cooking, hold or chill, plating, then wash-up. Keeping raw and ready-to-eat paths separate is a core HACCP principle and the single best way to design out cross-contamination. Draw the flow first and let the equipment fall onto it, not the other way round.
3. Size the extraction and the make-up air together. Under DW/172 the extract canopy has to move enough air to capture grease and fumes at source, and that extracted volume must be replaced with tempered fresh air - typically around 80 to 90 per cent of the extract rate - to avoid pulling the room into negative pressure. Get this balance wrong and doors slam, gas appliances misbehave and the whole system fights itself. Aim for the air-change and velocity figures the standard sets rather than guessing.
4. Specify canopies and filters properly. A capture canopy should overhang the cooking line by at least 250mm on the front and open sides, rising to around 600mm over combi ovens and other high-plume equipment. Behind the baffle filters the system needs to hold enough velocity - in the order of 0.6 m/s for medium and heavy-duty ranges - so grease stays entrained in the airstream instead of settling in the duct. Stainless, non-combustible construction throughout is not optional.
5. Interlock the gas from the outset. Any gas cooking line needs a BS 6173 gas interlock so the supply cuts off automatically if the extract or make-up air fails. Designing the interlock in now - rather than retro-fitting it under enforcement later - keeps the wiring tidy, the commissioning clean and the Gas Safe sign-off straightforward.
6. Design for cleaning and access, not just for cooking. Around 70 per cent of commercial kitchen fires start in the extract system, in grease that could not be reached. Build in access panels roughly every two metres along the ductwork and at every change of direction, size the duct route so a technician can actually clean it, and choose surfaces and coving that wipe down in seconds. A kitchen you cannot clean is a kitchen that will eventually fail an inspection or catch fire.
7. Plan drainage, surfaces and services last but not least. Falls to floor gullies, sealed and washable wall finishes, adequate hand-wash basins, and enough electrical capacity with the right protection all have to be coordinated before the slab and walls are finished. These are cheap to build in and ruinous to add afterwards, so lock them down at design stage.

Where designs quietly go wrong

Most of the trouble we see on established sites traces back to a single early compromise. Extraction is the usual culprit. A duct routed for the shortest builder's run rather than for cleaning access looks fine on the drawing and passes its first commissioning, but within months grease is accumulating in the sections no brush can reach. TR19 Grease, the industry code of practice, expects the internal grease film to be kept below 200 microns - thinner than a bank card - and that target is simply unachievable if the duct was never designed to be opened up. Access panels every couple of metres cost very little at the fit-out stage and pay for themselves the first time a technician needs to prove a clean to your insurer.

The second recurring fault is air balance. Extraction and make-up air are two halves of one system, yet they are often specified by different people at different times. When the fresh-air supply lags the extract, the kitchen runs negative, back doors become impossible to open, combustion appliances starve, and CO₂ and heat build up around the line. Designing both together, to the volumes DW/172 sets out, keeps the room comfortable and the gas appliances behaving as their manufacturers intended.

Layout is the third. A kitchen that ignores the delivery-to-dispatch flow does not just risk cross-contamination - it makes the space miserable to work in, with staff constantly crossing and colliding at the peak. That matters more than ever. A calm, logical, well-ventilated room is part of how you keep good people, which is why retaining chefs from the inside out starts with the physical space they spend their shifts in. The same discipline scales down too: even a compact or temporary set-up has to honour the same extraction, gas and hygiene logic, as anyone planning to run a compliant pop-up kitchen quickly discovers.

None of this is exotic engineering. It is a handful of standards - DW/172, BS 6173, BS EN 16282, Part F and TR19 Grease - applied in the right order, early, by people who understand how the finished room will be used and maintained. Design against them from the ground up and you will never have to reverse-engineer compliance into a room that was built to fight you.