How to design the layout of storage units on your site

The Golden Rule: Maximise Rentable Square Footage

The primary goal of your layout is to achieve the highest possible ratio of Net Rentable Square Footage (NRSF) to the total building area. In the UK storage industry, a common target is to ensure that 70% to 85% of your total floor space is occupied by income-generating units, with the remainder dedicated to corridors, reception, and structural elements. Every square metre of corridor is space you cannot charge for, so your design must be as efficient as possible.

1. Determine Your Unit Mix

Before drawing lines on a floor plan, you need to decide on the variety of sizes you will offer. A healthy mix usually includes:

• Small (10–25 sq ft): Ideal for students, seasonal decorations, or hobbyists. These are often placed in less accessible areas or upstairs.
• Medium (50–75 sq ft): The 'bread and butter' size for people moving house or small businesses.
• Large (100–200+ sq ft): Aimed at full house moves or commercial stock storage. These should ideally be closer to loading bays or ground floor entrances.

Use a 'Tetris' approach: place larger units at the end of corridors and use smaller lockers to fill awkward gaps around structural pillars or under staircases.

2. Optimise Corridor Widths and Traffic Flow

Corridors must be wide enough for customers to manoeuvre trolleys and bulky furniture without damaging your walls. For internal facilities, aim for a minimum corridor width of 1.2 to 1.5 metres. Avoid 'dead-end' corridors where possible, as they can lead to congestion; a loop system is much more efficient for customer flow.

If you are designing an outdoor site with shipping containers, vehicle access is your priority. You must ensure there is enough 'swing space' for a large van or even an HGV to turn. A standard road width of 6 to 9 metres between rows is typical to allow for two-way traffic and loading space.

3. Door Selection and Placement

The type of door you choose significantly impacts your layout:

• Swing Doors: These are cheaper but require 'clearance' in the corridor to open. They are best for smaller lockers.
• Roll-up Doors: These are the industry standard for units 50 sq ft and larger. They save space as they don't swing out into the corridor, allowing for slightly narrower walkways.

Ensure that every unit door is easily accessible. A unit that is hard to get into is a unit that will remain unrented.

4. Consider Customer Convenience

High-demand units (the ones people access most frequently) should be located near the loading bays. If your facility has multiple floors, ensure the units furthest from the lift or stairs are the larger sizes, as these customers typically visit less often than someone with a small 'hobby' locker.

Top Tip: Use masking tape on the floor of your empty building or site to map out a few units and a corridor. Walking the space physically can reveal 'pinch points' that aren't obvious on a 2D drawing.