The new Part M, which came into effect on 1 May, says that there should be a limit on the opening force of fire doors. It states that the maximum force for a person to manually operate a self-closing door should be no greater than 20N at the leading edge.
However, this provision conflicts with fire safety standard BS EN 1154 Table 1. This states that door closers of size three – EN3 – and above must be used on fire doors. These require a closing force of 20N, which equates to an opening force of 36.35N.
This assumes that the efficiency of the closer is 55% (the minimum efficiency requirement for EN3). If closers were 100% efficient then the closing force would be equal to the opening force, but no manufacturer has developed a manual door closer capable of this.
For specifiers to comply with this fire regulation, their doors will have to far exceed the maximum force allowable in the new Part M – unless the doors specified are power-operated.
Part M's solution is that, where it is not possible for a person to open the door using a force of 20N, a power-operated door opening and closing system should be used.
By fire-engineering the building the designer might also avoid the requirement for fire doors.
Both solutions will add expense to the door costs, and for a small building they will be disproportionately expensive.
The Office of the Deputy Prime Minister admits the closer issue needs clarification. "We are aware that there may be some detailed design challenges associated with Part M and the use of self-closing doors," said a spokesperson. "We have therefore recently been in discussions with the relevant stakeholders within the industry and have agreed to assist them in the preparation of a industry guidance document on the subject."
In the meantime, specifiers will probably have to provide access statements explaining why the closers do not meet Part M requirements, and explain what alternative route to compliance they have taken. Door manufacturer Dorma already has access statements prepared for all its closers.
Trade group defends metal door handles
The Association of Building Hardware Manufacturers has sought to dispel fears that the specification of stainless steel and polished brass door handles will lead to designers being sued under the Disability Discrimination Act.
Part M of the Building Regulations governing access states that all door opening furniture should contrast visually with the door surface, and that the difference in light reflectance value between the two surfaces should be at least 30 points.
A report by Reading University examining the tonal contrast between doors and ironmongery suggested that visually impaired people could have problems locating door handles made from stainless steel and polished brass. This caused fears that certain combinations of handle and door surface could lead to architects being sued by people claiming that the design discriminates against them.
The ABHM says that architects and specifiers should continue to specify metal products.
"We want to reassure specifiers and end users that it is business as usual when it comes to choosing stainless steel and polished brass door levers and pull handles," said David Whitworth, ABHM chairman.
"There is no approved simple method to calculate the proposed 30-point visual contrast between door furniture and the door. Many factors affect the contrast in any particular location, such as levels of natural light, how light is reflected off walls and ceilings, the juxtaposition of the door and adjacent windows and different levels and types of natural light present," he said.
British StandardsBS EN 12412-2:2003
Thermal performance of windows, doors and shutters. Determination of thermal transmittance by hot box method. Frames.
This European standard specifies a method, based on BS EN ISO 8990 and BS EN ISO 12567-1, to measure the thermal transmittance of frame and sash components of windows and doors. Price £104, BSI members £52
BS EN 12412-4:2003
Thermal performance of windows, doors and shutters. Determination of thermal transmittance by hot box method. Roller shutter boxes.
This European standard specifies a method, based on BS EN ISO 8990 and BS EN ISO 12567-1, to measure the overall thermal transmittance of a roller shutter box in a hot box. Price £88, BSI members £44
BS EN 12608:2003
Unplasticised polyvinylchloride (PVCu) profiles for the fabrication of windows and doors.
Classification, requirements and test methods. This European standard specifies classifications, requirements and test methods for unplasticised PVCu profiles for the fabrication of windows and doors. Price £74, BSI members £37
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