All entrances should be illuminated and have accessible level access over the threshold level and the main entrance should be covered.
An accessible threshold at the entrance should be provided. Where unavoidable, a maximum 15mm upstand may be incorporated.
Under Part M of the building regulations the responsibility for the successful design of an accessible threshold lies with the builder/architect. This is often perceived as a challenge. However, there are many working examples of successful solutions to draw on. Set out below in diagrams 4b to 4f are suggested solutions incorporated in the industry guidance documents on accessible thresholds, published by The Stationery Office.
While these examples are not exhaustive and many proprietary thresholds will continue to develop, most design situations are catered for. It should be noted that a covered entrance, as required by Lifetime Homes standards, can also contribute to weather-proofing.
Here the frame is set back 30mm from the face of the external wall and a timber sill is used.
The frame is set back 55mm from the face of the external wall and a concrete sill is used. Because of the threshold/floor level differential, an internal transition unit is introduction to facilitate access.
The door is in a ‘check’ reveal; the frame is set behind the outer leaf of the outer external wall. This design incorporates a site-formed drainage slot.
Timber is used for both the sill and the internal floor. Once again because of the differential levels, a transition unit is incorporated in this design.
This design uses materials that have become increasingly popular in both renovation and new-build. The sill and door-frame are both PVC-U.