DOORS – THRESHOLDS AND ACCESS
Mention door thresholds and their need to comply with Building Regulations and it’s common to assume this means wheelchair access. While this is an important consideration, it is not the only one. The requirement is that reasonable provision shall be made for people to gain access to the building.
This means thinking about all users, paying particular attention to wheelchair users and other people with mobility problems such as older or blind people.
When assessing any door’s need to comply with Approved Document M, the first items that need to be addressed are location and position. Approved Document M relates to the main access door, however best practice should be applied to all doors wherever possible.
The main door is usually the entrance that would normally be used after a person has exited from a vehicle and approached the property. In most cases this is the front door but do remember UK housing stock also has a large proportion of properties with main access to the rear of a building.
When surveying the door, the original threshold height should be measured and ideally any replacement should be no worse than that already in place. In some cases this is an impossible task – for example, timber doors on stone cills with no current threshold. In areas of low weather exposure a threshold of no greater than 35mm cill height should be installed, extending to 50mm in areas of high weather exposure.
The clear opening of the main access door must also be made no worse than the original provided the opening is less than 775mm. If the original is greater than this, then the opening may be reduced to 775mm. Measurement is always taken from the face of the door leaf when open at 900 to the edge of the frame on the latch side.
It is common practice when using PVC-U to use an “Add-on” profile down the hinge side to stop the hinges fouling on the plaster-line. Remember these profile pieces reduce the width of the door opening so the door should be properly assessed as to whether it needs them and to establish the smallest size required to obtain the desired result.