The Regs: Part G
Geoff Wilkinson explains the new guidelines in Building Regulations Part G, due in April
Part G of the Building Regulations will change on 6 April. That leaves just six weeks to get approval before the amendments take place. Architects may find that their local authority cannot process an application before the new rules take effect. However, CLG (Communities and Local Government) is unable to confirm the date when the guidance document will be published. I would recommend that architects get in touch with an approved inspector if they need approval before the changes take place.
The regulations extend the scope of control, for example by stipulating that sanitary conveniences may be replaced only if the replacement will not result in an increase in water usage. Another important change is that Part G applies to previously exempt buildings, such as domestic greenhouses and conservatories, if they are served by a water supply from a dwelling.
Here’s a detailed look at each of the new parts:
G1 – Water supply
G1 requires that a supply of wholesome water must be provided for the purposes of drinking, washing and food preparation. A simple note that wholesome water will be provided to any washbasin, bidet, fixed bath or shower, and to any sink in an area where food is prepared, is all that is needed.
G2 – Water efficiency
The potential consumption of wholesome water must not exceed 125 litres per person per day. Architects will need to undertake a calculation using the methodology set out in CLG’s Water Efficiency Calculator for New Dwellings, and submit it as part of the plan assessment process.
To help with the calculation, water and environmental consultancy WRc has developed an online version of the water efficiency calculator, which can be found at www.wrcplc.co.uk/PartGCalculator.
Once the work has been carried out on site, the person responsible has five days to provide the building control body with a notice specifying the potential consumption of wholesome water per person per day in relation to the completed dwelling. Work cannot be certified complete until this notice has been received. Clients should also be advised that changes to the architect’s specification, e.g. a different bath, could result in a completion certificate being withheld. This requirement applies only to dwellings created through new build or conversion.
G3 – Hot water supply and systems
G3 is a new requirement that heated wholesome water be supplied to any wash basin or bidet in or adjacent to a room containing a sanitary convenience; any wash basin, bidet, fixed bath or shower in a bathroom; and any sink in an area where food is prepared. Again, a simple note is all that is required to be added to the drawings.
However, it is the final part of G3 that is the most important. It applies to dwellings created through new build or conversion and aims to prevent scalding by setting a maximum temperature for the hot water supply to any fixed bath at 48°C. This combination of water saving, reduced flow and thermostatic protection means that some of the mixing valves currently on the market will be operating at the very extreme of their envelope of performance and may no longer be suitable. Architects should check with manufacturers that their product is suitable for the proposed use before including the product in their drawings.
G4 – Sanitary conveniences and washing facilities
G4 replaces the former G1, but is broadly consistent with it. In the revised technical guidance, which clarifies the precise requirements of the approved documents, there is additional information on the separation of sanitary accommodation from places used for the preparation of food, which hopefully answers the issue of when lobbies are required once and for all.
G5 – Bathrooms
The new G5 replaces the former G2, but the requirements are broadly consistent. The revised technical guidance of the approved documents serves mainly to clarify the precise requirements.
G6 – Food Preparation areas
G6 contains a requirement that sinks must be provided in areas where food is prepared.
The new requirements apply to all projects that haven’t been approved or commenced before 6 April 2010. It should also be pointed out that even if plans are approved, unless the project starts before 6 April 2011 the approval will expire and it will be necessary to comply.
Geoff Wilkinson is a building regulations expert and former vice-chair of the Association of Consulting Approved Inspectors (ACAI)