Warehouse Layout Planning: Clear Height, Aisle Width and Capacity
Direct answer: Warehouse capacity is decided by three numbers used together: usable clear height sets how many beam levels fit, aisle width sets how many rack runs fit across the floor, and truck type links the two. Changing any one of them changes total pallet positions, so they have to be planned as a single calculation.
Clear height sets the number of levels
Before any rack is drawn, measure the usable clear height at the worst point in the building rather than the best: under roof trusses, under services and at the loading doors. Selective pallet racking is built to heights up to 12 m with the number of levels set by the available headroom, and our engineers normally design to the lowest obstruction in the proposed storage area rather than to the ridge height. Getting this measurement wrong is the most common reason a layout has to be redrawn.
Different systems have different ceilings. Pallet flow racking is typically built to around 8 m, cantilever racking to around 8 m, mould racks to about 6 m because the drawers are crane-served, and very narrow aisle installations are worked by turret trucks operating up to roughly 12 to 14 m. Where clear height is limited but the operation is picking rather than bulk storage, a two or three tier mezzanine is often the better use of the same volume. Check the roof structure before committing to height as well, since services, sprinklers and lighting all consume usable cube.
Aisle width follows the truck
Aisle width is decided by the handling equipment, and choosing the truck before the rack is the usual order. Standard selective racking with a reach truck needs roughly 2.5 to 3.5 m; manual and order-picker shelving aisles run about 1.0 to 1.8 m; cantilever racking served by a sideloader or crane needs about 3.0 to 4.0 m; and flow racking needs about 1.5 to 2.5 m at the pick face, with the replenishment side kept separate to avoid cross-traffic. Where two truck types share a building, the widest one dictates the aisle, so separating the zones usually recovers space.
Compressing the aisle is the most direct way to recover positions. Very narrow aisle racking brings the working corridor down to 1.6 to 2.0 m and is worked by a turret truck whose forks rotate and side-shift without the truck body turning, which adds roughly thirty per cent more pallet positions on the same footprint. The trade-off is the truck itself and the guidance: floor-embedded guide rails, or magnetic or laser navigation, are used to prevent column impact at that clearance.
What to send for a layout
Four pieces of information are enough to start: the floor plan with column positions and door locations, the usable clear height, the pallet dimensions and weights including any overhang, and the throughput or number of pallet movements per day. From those we return a CAD layout with capacity calculations and FOB pricing, normally within 48 hours, together with a structural calculation sheet based on FEM 10.2 and EN 15512. The same drawing package later drives the container loading plan for 20GP or 40HQ shipment.
Pilots are cheap. Standard racking starts from five bays and a single bay can be supplied for a project pilot; standard steel pallets start from ten pieces with custom prototyping from one piece. Standard production runs 18 to 30 days per container, and 30 to 45 days for container-sized automated projects after drawing approval. Send the floor plan and we will tell you what the building will actually hold. Drawings, load reports, installation plans and certificate scans are supplied on request, and quotations are returned within 24 hours.
FAQ
How much clear height do I need for a mezzanine?
Mezzanine structures are generally considered once clear height reaches about four metres, and they are built two or three tiers high. Structural mezzanine floors are specified at 300 to 1,000 kg per square metre and rack-supported versions at 300 to 800 kg per square metre, both with 1,100 mm safety railing and integrated staircases. Send the clear height and the intended load and we will confirm whether a platform or higher racking gives the better return.
Can I narrow existing aisles to gain pallet positions?
Yes, but the truck has to change with the aisle. Narrowing a reach-truck aisle to 1.6 to 2.0 m requires a turret truck and usually some form of guidance, since the tolerance for column contact disappears at that clearance. The gain is roughly thirty per cent more pallet positions in the same footprint. We model both options in the CAD layout so you can compare the capital cost of the trucks against the storage gained.
Is the CAD layout really free?
Yes. Send the floor plan, clear height, pallet specifications and weights and throughput, and our engineers return a CAD layout with capacity calculations and FOB pricing within 48 hours, together with a structural calculation sheet to FEM 10.2 and EN 15512. There is no charge and no obligation, and the same drawing package is used later for the container loading plan.
All figures above refer to standard product data sheets; final confirmation is subject to written quotation.