ºÃÉ«ÏÈÉúTV

The act encompasses BS8300, which sets out various requirements in respect of door-closing devices on all door types within a building. BS8300 details the maximum closing forces that are permissible on doors in an attempt to keep opening forces as low as possible, resulting in ease of operation of the door by users.

The closing forces detailed in BS8300 are as follows:

• Main entrance door: 20 Newtons
  
• Circulation route (single-action door): 20 Newtons
  
• Circulation route (double-action door): 30 Newtons
  
• Internal fire door not on circulation route: 30 Newtons
  
• Other internal door not fire-rated: 20 Newtons

Door manufacturer Dorma says, however, that it is the opening forces that can lead to difficulties in operating a door. Although there is a direct relationship between opening and closing forces, the differential will depend on the type of mechanism used and its efficiency.

Although high efficiency and power adjustment both contribute to lower opening forces, cam-action mechanisms improve the operation of the door to an even greater extent, says Dorma. With a cam-action door closer the opening force falls away very rapidly after the first few degrees of opening a door, resulting in very little resistance; on closing the reverse results.

To comply with BS8300 and ensure the lowest opening forces possible Dorma recommends the following specification for door closers:

• Third party type tested to BS EN1154
  
• Rack and pinion should not be combined with slide arms
  
• Adjustable power
  
• Cam action mechanism.

For more information contact: www.dorma-uk.co.uk

Making door handles easy to see
A joint report has been published that examines the tonal contrast between doors and ironmongery. The report, Adequacy in colour contrast between a range of door finishes and door furniture for people who are visually impaired, is a joint effort between Reading University, RNIB and ICI, and sponsored by door manufacturer Turnquest.

All specifiers will have to be aware of colour and tonal contrast between doors and ironmongery when the Disability Discrimination Act is published in October 2004. Certain colour combinations may fall foul of this act as they would make it difficult for visually impaired people to find door handles. As polished metal has a high reflectance, the report found that the partially sighted had problems discerning between polished stainless steel and brass handles and the door surface.

The report indicates what colour combinations provide an acceptable contrast between the door and handle. With wood-finish door colours, the report found that satin and polished stainless steel and polished brass door handles did not offer enough contrast with the door surface. Satin aluminium and polished aluminium were found to offer a suitable contrast when used with sapele, white oak and cherry wood colours.

With a formica door finish, the research team found that satin stainless steel could be used with some colours but polished stainless steel and brass offered poor contrast with all formica doors.

A tone and contrast palette will be available at the end of this month from marketing@turnquest.co.uk and www.buildforhealth.co.uk.

New Part L standards – energy efficiency
The 2002 changes to the Part L ºÃÉ«ÏÈÉúTV Regulations saw the adoption of standards that had been advocated as best practice by the government's Energy Saving Trust for a number of years. In fact, the existence of best practice standards and their adoption by some parts of the market is what made the transition relatively painless, according to the EST.

Work on the next round of revisions to Part L of the ºÃÉ«ÏÈÉúTV Regulations has already started and the EST says that its current best practice U-value should be adopted as standard once again. The government's best practice specification uses the carbon index to give specifiers some flexibility, but limits trade-offs by using acceptable maximums for the different elements. Larger houses, or those using liquefied petroleum gas or electric heating, may need tougher U-values.

The maximum U-values for windows are 1.8 W/m2K (best practice) and 1.5 W/m2K (advanced practice). Both these figures appear in a draft document entitled Possible Future Performance Standards for Part L. A U-value of 1.8 can be achieved quite readily, according to EST and is a requirement for some houses in Scotland (elemental method).

Examples of specifications meeting this standard are: