Sanitary conveniences and washing facilities

Number, Type and Siting of Appliances

2.2 Guidance on the scale of provision, selection, installation, and special requirements of sanitary appliances in domestic, commercial and public buildings is contained in BS 6465 Sanitary installations, Part 1; Part 2 ; Part 3 and Part 4.

2.3 Technical Guidance Document M should be consulted for guidance in relation to the provision of accessible sanitary conveniences. Certain types of buildings, offices, shops, factories, etc., may also be subject to specific legislative requirements. The relevant legislation should be consulted.

2.4 Every dwelling (house or flat) should have at least one water closet and one washbasin. The washbasin should be located in, or adjacent to, the room containing the water closet.

2.5 A room or space containing a water closet should be separated from a place used for the preparation or cooking of food by means of: -

(a) in the case of a building used solely as a dwelling, a door, and

(b) in any other case, a properly ventilated passage or lobby.

Design and Installation

2.6 Any sanitary convenience (water closet or urinal) should be of such design as to facilitate efficient use of water for flushing. Any flushing device should be capable of cleansing the water closet pan effectively.

2.7 All water closets should have a maximum flush volume of 6 litres or less and comply with the requirements for class 2 products in I.S EN 997: 2003 regardless of the type of flushing device employed. The type of flushing activator, e.g. handle, button, sensor etc., will be dependent on particular design situations. For all manually activated flushing devices (except pressure flushing valves) a dual flush facility combining a maximum flush volume of 6 litres and a reduced flush volume no greater than two thirds of the maximum should be used.

The method of activation of the dual flush should be readily discernible, e.g. separate buttons or pads of different sizes, segmented buttons (two-thirds, one third) etc.

In non-domestic buildings, consideration should be given to displaying clear and permanent operating instructions for users.

Technical Guidance Document M should be consulted for guidance in relation to accessible WCs.

2.8 Guidance on Drainage and Waste Water disposal given in Technical Guidance Document H is based on a maximum flush volume of 5 litres or more. Where WCs with maximum flush volumes of less than 5 litres are used, consideration should be given to the increased risk of blockages. Guidance on the design of sanitary pipework suitable for use with WCs with maximum flush volumes as low as 4 litres can be found in IS EN 12056.

2.9 When an existing WC suite, comprising of WC pan and flushing cistern is to be replaced by a suite incorporating a manual flushing device (except a pressure flushing valve), a dual flush facility as described in paragraph 2.7 should be installed. However, if the flushing cistern alone is to be changed, without changing the WC pan, the replacement should be of the same size as the one it replaces. A single flush cistern should not be replaced with a dual flush cistern, when the WC pan is remaining.

2.10 Every sanitary appliance should have a surface which is smooth and non-absorbent and capable of being easily cleaned.

2.11 A washbasin provided in, or adjacent to, a room containing a water closet should have a supply of hot water, which may be from a central source or from a unit water heater, and a piped supply of cold water from a storage cistern.

2.12 A cold water storage system should be designed and installed in accordance with the recommendations set out in BS 6700: 2006.

2.13 A water closet should discharge through a trap and branch pipe into a discharge stack or a foul drain. No part of the water closet pan should be connected to any pipe other than a flush pipe or branch pipe. See Technical Guidance Document H for guidance regarding drainage.

2.14 A washbasin should discharge through a trap and branch pipe to a discharge stack or may, where the washbasin is located on the ground floor, discharge into a gully.

Appendix

Table HG1 - Minimum insulation thickness (mm) to protect against freezing for domestic cold water systems (12 hour period) - Extract from TGD G