Access for all.
Approved Document M (AD M), 2004 edition
Incorporating 2010 and 2013 amendments
The main requirements set out in AD M are, as with all parts of The Building Regulations, performance based and the guidelines set out in the document are recognised as one way of achieving the requirements. The scopes of the requirements are clearly set out, requiring that provision is made for people to "a) gain access to and b) use the building and its facilities". This includes the provision of sanitary accommodation in domestic and non-domestic buildings. AD M applies not only to new building but also to alterations and extension of existing buildings. Where certain issues are not covered within AD M, further reference will be made to BS 8300. AD M contains a number of very specific requirements for the following aspects related to architectural hardware specification.
This standard provides guidance on good practice in the design of buildings to make them suitable for use by disabled people. The standard is often used as a supplement to AD M and includes more specific dimensional guidance, particularly regarding the sizes of door operating hardware. BS 8300 contains the following recommendations related to architectural hardware specification.
AD M recognises that negotiating entrance doors can be difficult for the general public, not just disabled people: parents with children, those carrying luggage or with pushchairs etc.
It is stated within AD M that doors which are required to be self closing must require a force no greater than 20N at the leading edge in order to open them. In most practical applications "A powered door opening and closing system is the most satisfactory solution for most people" (AD M 2.13). Although the 20 Newtons rule technically still exists it has been generally superseded by a two-phase criteria established within BS 8300 in 2005. This states a maximum opening force of 30N at the initial opening stage (0˚ to 30˚), reducing to 22.5N from 30˚ to 60˚ opening angle.
Aside from the headline figures of AD M, the guidance in BS 8300 points clearly to the use of powered solutions including low energy operators to achieve the level of accessibility required on external doors (including recommendations for the positioning of any manual controls.
Fire & Smoke Doors
BS EN 1154 requires fire doors to be held closed by a door closer with a minimum power size 3. This requires a force in excess of 20N (see chart below) and therefore puts it into conflict with the 20N opening force requirement of ADM. In these circumstances AD M recommends the use of electromagnetic hold open or low energy door operators. For fire doors within corridors the preference is for electromagnetic hold open units. Where privacy is still a requirement, such as doors to individual rooms, an electromagnetic device which offers a 'swing free' facility is preferable.
Doors to escape stairs and final exit doors are not specifically covered in AD M. In BS 8300 it is considered suitable to use a conventional door closer in these cases, as such doors are likely to be opening in the direction of escape (i.e. push to exit). In these situations BS 8300 recommends a maximum opening force of 30N.
Closing & Opening forces
As can be seen from the chart opposite, a door closer power size 1 with only the minimum efficiency allowed in the EN standard (50%) will not satisfy the maximum opening force to satisfy the 20N limit in AD M. Also clearly evident is the fact that a power size 3 closer (the min. allowed in satisfying the requirements for a fire door) has an opening force at the edge of the door beyond the 30N maximum allowed in the revised regulations. Only high efficiency closers will therefore meet the dual requirements for an accessible fire door.
For internal doors which need to be self closing for privacy or environmental reasons, they must meet the maximum opening force criteria of 20N. In these circumstances a high efficiency variable power door control is required. When set to the lowest strength (size 1) to reduce the opening force it may cause problems in latching the door, especially in locations which may be susceptible to drafts or air pressure differences. Locks with a 'soft action latch' and high quality hinges will help in making sure the door latches properly each time.