What is the minimum loft hatch size in the UK?

The minimum loft hatch opening per UK Building Regulations is 726 × 526mm (sometimes stated as 726 × 566mm for many ladder types). This is the clear opening size, not the frame size. If you are installing a loft ladder, you will typically need to enlarge the hatch to at least 1130 × 570mm for a 3-section ladder.

What type of loft ladder should I choose?

Three-section sliding aluminium ladders (like the Youngman Easiway or Werner range) are the most popular choice in UK homes. They fold compactly into the loft and are suitable for floor-to-floor heights up to about 3.05m. Two-section ladders suit lower ceilings (up to 2.6m). Concertina (scissor) ladders are ideal for very tight spaces as they fold vertically and need a smaller hatch opening.

How do I measure floor-to-floor height?

Floor-to-floor height is measured from the finished floor surface of the room below (where the ladder feet will rest) to the top surface of the loft floor (on top of the ceiling joists). This is typically ceiling height plus the depth of the joist and floorboard above. In most UK houses, floor-to-floor height is between 2.5m and 2.8m.

How much clearance do I need below the loft hatch?

You need clear floor space below the hatch for the ladder to deploy. For a standard 3-section ladder at a 70-degree angle, you need approximately 1.0-1.2m of clear floor space in front of the hatch. Do not position the hatch directly above stairs or in narrow corridors where there is insufficient landing space.

Do I need Building Regulations approval for a loft ladder?

If you are installing a loft ladder purely for access to storage (not a habitable room), Building Regulations approval is generally not required. However, if the loft is a converted habitable room, the staircase or ladder must comply with Approved Document K. A proper fixed staircase is normally required for habitable loft conversions — a loft ladder is not adequate.

Loft Ladder Sizing Calculator — What Size Loft Ladder Do I Need?

How We Calculate This

This calculator determines the correct loft ladder length, recommends a ladder type, and checks whether your existing hatch meets Building Regulations minimum sizing.

Ladder length

Required ladder length = Floor-to-floor height + 100mm

The extra 100mm provides an overlap so the ladder extends slightly above the loft floor level, ensuring safe entry and exit.

Hatch sizing

Minimum hatch (Building Regs): 726 × 526mm clear opening
2-section ladder: Requires at least 726 × 566mm hatch
3-section ladder: Requires at least 1130 × 570mm hatch (1200 × 600mm recommended)
Concertina ladder: Requires at least 600 × 600mm hatch

Clearance below hatch

The horizontal footprint when deployed is calculated from the ladder angle (approximately 70° from horizontal). This tells you how much clear floor space is needed beneath the hatch opening.

Floor-to-floor ranges

2-section: Up to 2.6m floor-to-floor
3-section: Up to 3.05m floor-to-floor
Concertina: Up to 3.0m floor-to-floor

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.