Warehousing and Logistics Buildings: What They Demand

A warehouse is sold on cubic capacity and throughput

A warehouse earns its rent, or justifies its capital, by how many pallet positions it holds and how fast goods move in and out. Floor area is only the start of that. Two sheds of the same footprint can differ widely in usable capacity once clear height, floor quality, dock arrangement and fire protection are taken into account.

The common misconception is that a warehouse is a simple box and the hard part is the price of steel. In practice the expensive mistakes are quieter: a slab that cannot take the racking an operator wants, a haunch or sprinkler main that costs a pallet level, docks that queue trucks at peak hour, or a roof that leaks over stock. Each one is either rework in a building already in use or a permanent loss of capacity.

Where Hagerstone services apply

The racking plan sets the floor and the height

Everything in a warehouse is measured from the racking. The rack type and the handling equipment decide how high goods are stacked, how narrow the aisles are and how flat the floor must be. Narrow-aisle trucks lifting to height are far less tolerant of an uneven floor than counterbalance forklifts in wide aisles, which is why floor flatness is specified for the truck and measured to a defined method such as ASTM E1155. Racking tolerances and clearances are covered separately under EN 15620, which explicitly leaves the floor to its own specification.

Clear height is lost from the top down. The portal frame haunch, sprinkler mains, light fittings and any ductwork all sit below the roof sheet, so the useful number is the height to the lowest obstruction across the racking zone. That is a coordination task between the steel, fire and electrical designs, settled before fabrication. The detail of floor loads, joints and curing is covered in decide the racking before the warehouse slab.

Docks, roof and lighting decide daily throughput

Docks fix more of the site plan than most owners expect: door count and type, leveller pits, canopies, apron levels, yard depth and the turning space trucks need. Inbound and outbound patterns change the answer, which is why warehouse loading dock design starts from the operator's volumes rather than a standard count.

Roofs on large sheds fail at the same few places: rooflights, end laps, fasteners and gutters. A leak over a racked aisle damages stock and stops picking, so laps, fixings and rooflight upstands deserve inspection as they go in. See warehouse roof leaks at skylights and sheet laps.

Lighting has to reach the faces of the racks, not just the aisle floor, and fittings must avoid the trucks' lift path. Daylight from rooflights helps, but only if it is planned with the roof layout. The general framework for working interiors is in IS 3646 (Part 1); the practical choices are covered in warehouse lighting with high-bay fittings and daylight.

Fire protection is a framework set early

Storage buildings fall under the fire and life safety provisions of NBC 2016, Part 4. What is stored, how it is packed, how high it is stacked and how the racking is arranged all influence the protection the fire consultant designs, and some arrangements bring sprinklers into the racking itself, which changes the rack design. Compartmentation, fire tender access around the building and the pump room location also shape the site plan. These are decided by the fire consultant and the authority having jurisdiction, and the earlier they see the racking plan the less the building has to change.

Common mistakes

• Designing the shed before the racking. The frame, slab and sprinklers get fixed around an assumption nobody wrote down.
• Quoting height to the eaves. The operator loses a pallet level to the haunch or the sprinkler main.
• One floor specification for everything. Dock zones, racking zones and staging areas see different loads and traffic.
• Treating docks as doors. Apron levels, leveller pits and yard depth are civil works that cannot be added cheaply later.
• Leaving rooflights to the sheeting crew. Upstands and laps around them are where large roofs most often leak.

What to ask your warehouse builder

• Which racking system and handling equipment is the design based on, in writing?
• What is the clear height to the lowest obstruction across the racking zone?
• How is floor flatness specified, and how will it be measured at handover?
• How were the dock count, type and yard depth worked out?
• Has the fire consultant seen the stored goods and racking plan?
• What structural allowance has been made for mezzanines, plant or future solar?

Standards referenced

Fire and life safety for storage occupancy under NBC 2016, Part 4; steel design to IS 800:2007; racking tolerances and clearances in EN 15620; floor flatness measurement to ASTM E1155; interior lighting in IS 3646 (Part 1). Loads, floor specification, fire protection and lighting levels for a particular warehouse are established by the project's structural, fire and electrical consultants and the authority having jurisdiction.