Water efficiency limit for a new dwelling

125 litres per person per day (110 where the tighter optional requirement is imposed by condition)

New dwelling water efficiency calculation

Maximum calculated water consumption for a new dwelling under the national standard.

Basis in regulation

Part G
Approved Document G
Read the source

How to check it on site

Check the fittings actually installed against the schedule used in the calculation — a changed shower head can break the figure.

Common failure

Sanitaryware substituted late for programme reasons without re-running the calculation.

Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.

Related dimensions at this stage

Minimum

Additional flue terminal separation rules

300 mm

Beyond standard table distances, all flue terminals must maintain a minimum 300mm clearance from any combustible material, such as window frames

Minimum

Landscaping Levels and DPC

150 mm

External ground levels, including landscaping finishes such as turf, must be maintained at a minimum of 150mm below the damp proof course (DPC) level

Maximum

Accessible threshold upstand

15 mm maximum total upstand, chamfered or pencil-rounded above 5 mm

Principal entrance to a dwelling designed to be accessible

Minimum

Specific guarding requirements for level changes

600 mm

Guarding is mandated for retaining structures where the drop is greater than 600mm to an accessible lower level

exact

Handrails for external steps

600 mm

A handrail is required for external flights of steps when the total rise exceeds 600mm and the individual step going is less than 600mm

Maximum

Gutter bracket spacing

600 mm

gutter brackets are spaced no more than 600mm apart along the gutter run.