APHC comments on the changes to Part G of the building regulations and suggests water efficiency calculation be available at the planning stage to prevent specification problems.

Changes to Part G of the building regulations in 2010 saw the introduction of a mandatory requirement to limit water consumption in new-build properties to 125 litres per person per day.

The consumption (based on occupancy) is established using a relatively complex water efficiency calculator approved by CLG.

The 125 litre per person per day rate is quite low and has significant impact on the design of the system typically requiring restrictions on bath size, potentially requiring flow restrictors to taps etc.

On completion of the works there is a requirement in the Approved Document for those 'completing the works' to confirm compliance with the efficiency requirement through issuing a certificate.

This water efficiency certificate is now a requirement for building control to sign off any new build property.

However, in some cases Designers / Architects are largely ignoring the water calculation requirements by continuing to specify large baths, high flow showers etc at the building design stage creating significant problems at a later date when it comes to providing the required certification. 

The situation is made worse by the fact that regulations only stipulate that certification is required with supporting calculations on completion of the works. 

A simple solution to this problem would be to require the water efficiency calculation and hence the plumbing design specification for the work to be available at the planning stage of the project as well as on completion.

John Thompson, Chief Executive APHC, commented “APHC has had feedback from a number of members who have been pushed to carry out works in line with property developer/Architect/designer specifications only to find at the end of the job that they have been left with the responsibility to provide water efficiency certification, which when completed does not fall within the 125 Litre consumption rate. In a number of cases the contractor has been left with the responsibility to foot the bill for necessary remedial works.

APHC would like to propose an amendment to the government related to regulatory change, but before we can do this we need more support.