We regularly come across scenarios where there appears to be a conflict between the requirements of one regulation or requirement and another.
Requirement B1, Means of warning and escape of the Building Regulations requires means of escape windows in the upper storey of a house to be positioned in such a way that people can readily climb out of them in the event of a fire. This requirement can create problems when trying to design a layout that involves placing a room in the centre of the house with a window overlooking a side boundary. Whilst the Building Regulations require the escape window to be positioned with the opening no higher than 1100mm above the floor level, the planners will want to protect the privacy of the neighbouring property and they do this by controlling the type of glass or the position of the window. If the proposed window would look out over a boundary to an adjacent property the planners are likely to ask for the window to be either non opening and obscured, or positioned at a height of more than 1700mm above the floor. A non opening window with obscured glass in a bedroom is likely to be claustrophobic, would not comply with B1 or indeed F1 Ventilation, whereas a window placed at 1700mm above the floor would also not comply with the requirements for means of escape. Even though B1 is concerned with saving people’s lives in the case of the fire it will not trump the planning requirements for protecting the privacy of neighbours. If your design relies on this solution it is time to come up with another design.
In Victorian or Georgian properties sash windows are often positioned with the cills a short distance above the upper floor level. Heights of 450 to 600mm for the height of the window above the floor level are not uncommon. The design of any extension to these properties is likely to work well when the position and shape of windows in the extended or altered part has some relation to the existing windows, indeed the planners may actually insist on it. Here the conflicting requirements stem from requirement K2 Protection from Falling of the Building Regulations which aims to protect people from falling out of an open window that is less than 800mm above floor level. A solution to keep both the planning office and building inspector happy is to incorporate a fixed guard on the inner face of the window at a height of 800mm.
Another conflict which clients often complain about appears to be between L1B Conservation of fuel and Power in Existing Dwellings and F1 Means of Ventilation. At first glance the need to have trickle vents to all rooms and mechanical extract fans in kitchens, bathrooms and WCs, or an alternatively system of permanent vents in the ceilings linked to a passive stack system appears contrary to the requirements of high levels of insulation and draught proofing as required to conserve energy and reduce CO2 emissions. But a greater understanding of the problems associated with condensation in buildings with highly insulated envelopes explains the reasons why the ventilation is so essential.
Requirement B1 can also require dramatic changes to the escape route when a two storey house is converted to a three storey building with a loft conversion. These requirements include the need to create a protected stairway from the new 2nd floor which would necessitate the existing doors in the house from bedrooms, living rooms and the kitchen that access the hallway and staircase being replaced with shiny new fire doors. Proposing this change on a listed building is likely to rub the Conservation Officer up the wrong way.
A full understanding of all regulatory requirements at an early stage of the design by a professional designer such as Space and Style Home Design can prevent the design running into unforeseen problems further down the line.