Part G of The Building Regulations (2000) covers sanitation, hot water safety and water efficiency. Several requirements were amended and captured in a new approved document published on 6th April 2010. Requirement G2 and Regulation 36 set out the new requirements on water efficiency in new dwellings. Requirement G2 states that reasonable provision must be made by the installation of fittings and fixed appliances. Building Regulation 36 requires that the potential consumption of wholesome water by persons occupying a dwelling must not exceed 125 litres per person per day when calculated in accordance with the methodology set out in the CLG’s document ‘The Water Efficiency Calculator for New Dwellings’.
In order to forecast the demand for water, Essex & Suffolk Water (ESW) and Northumbrian Water (NW) subgroup metered properties and apply specific per capita daily consumption figures to each group. The subgroups of metered properties are as follows; meter optant, selectively metered, existing metered and new properties. For the first three subgroups, it is possible to measure consumption accurately using meter read data. This provides the opportunity to estimate base year per capita daily consumption figures, from which it is possible to forecast into the future. Due to the very nature of new properties, the business does not have access to a series of meter reads of suitable length in time and therefore it is not possible to accurately measure consumption. In turn, the Part G figure of 125 litres per head per day is used to forecast demand as it is assumed the occupants of new dwellings will not exceed this level of consumption.
Specifically, the objectives were to:
- Identify at housing developments built between 2010 and 2012 in order to provide a sample of a minimum total of 500 properties.
- Interrogate the ICIS billing system to collect meter read data for each property on the identified housing developments,
- Gain an understanding of occupancy levels in the identified properties through a simple questionnaire,
- Analyse consumption data in order to understand the actual per capita water consumption in homes built to the amended Part G of The Building Regulations.