What is the minimum clearance in front of a WC?

The minimum recommended clearance in front of a WC is 600mm for a standard bathroom. For Part M accessible bathrooms, this increases to 750mm. You also need at least 200mm each side of the WC centre line (450mm for Part M) to allow comfortable use and cleaning access.

What does Part M mean for bathroom design?

Part M of the Building Regulations (Access to and use of buildings) sets minimum accessibility standards. For dwellings, Part M Category 1 (visitable) requires a ground-floor WC with 750mm frontal clearance and 450mm side transfer space. Category 2 (accessible/adaptable) and Category 3 (wheelchair user) have progressively larger clearance requirements.

What is the minimum bathroom size in the UK?

There is no absolute minimum bathroom size in UK Building Regulations, but the clearances around each fixture effectively determine it. A small en-suite with WC, basin and shower typically needs at least 1.2m x 1.7m (about 2 m²). A standard family bathroom with bath needs at least 1.7m x 2.4m (about 4 m²). These assume standard clearances, not Part M.

Should a bathroom door open inward or outward?

Building Regulations do not mandate door swing direction for standard bathrooms, but an outward-opening door saves space inside the room and is safer in an emergency (you can access someone who has collapsed). However, outward-opening doors require hallway clearance. Sliding or bi-fold doors are a good compromise for small bathrooms.

How much space do I need between a WC and a basin?

You need at least 200mm between a WC and an adjacent basin (measured between the edges of the fittings, not centre lines). This allows for comfortable use and cleaning. For Part M accessible layouts, allow at least 300mm. Many designers recommend 250-300mm as a comfortable standard gap.

TradeCalculator

Bathroom Spacing Calculator — Minimum Clearances & Layout

Check whether your bathroom dimensions meet minimum clearance requirements around WC, basin, bath and shower per UK building standards and Part M accessibility.

Room Length

Internal room length in mm

Room Width

Internal room width in mm

Select Fixtures

Part M accessible bathroom

Uses larger clearances for wheelchair accessibility

Door swings inward

Inward-swing doors consume floor space

How We Calculate This

This calculator checks whether your bathroom dimensions provide adequate clearance around each fixture based on UK building standards and Part M accessibility requirements.

The formula

Fixture footprint = (Width + 2 × Side clearance) × (Depth + Front clearance)

For a standard WC: (400 + 2 × 200) × (700 + 600) = 800 × 1300mm = 1.04 m². The calculator sums all fixture footprints and checks against available room area.

Standard clearances

WC: 600mm front, 200mm each side (Part M: 750mm front, 450mm side)
Basin: 700mm front, 100mm each side (Part M: 1100mm front, 300mm side)
Bath: 700mm along access side (Part M: 1100mm)
Shower: 700mm in front of opening (Part M: 1100mm)

Based on BS 6465-2 (space recommendations for sanitary appliances) and Approved Document M of the Building Regulations.

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.