Lobby Protection versus Fire Suppression
The entrance to flats very often features a lobby – a small hallway space between the front door to the flat and a second fire door which leads into the flat itself. Lobbies eat up valuable space and are often resisted by property developers. It's easy to see why: recovering a lobby space of 8m2 would be worth around £12,000 at UK average house prices and around £17,000 in London in 2013 (source). So why do we need these lobbies?
The Building Regulations guidance (Approved Document B part 2, sections 2.20 and 2.21) recommends that in blocks of flats which have more than one staircase or more than four storeys, the interior of every flat should be separated from its communal corridor by a protected lobby, so that two fire doors separate the shared corridor from the living areas of the flat. The main purpose of these fire lobbies is not to improve safety within the flat itself, but to slow the flow of heat and smoke from a fire in the flat into communal areas, ensuring that other flats in the building always have a safe escape route.
A fire door, however, is a relatively unreliable way to contain a fire in the room where it starts. Householders frequently remove lobby doors for aesthetic reasons and to gain space; moreover, the NHBC Foundation Report NF19 indicates that fire doors are normally propped open, even at night. Active fire suppression is a superior approach to containing a fire and is unlikely to be removed casually by the householder. The use of Automist in place of a fire door can therefore, in many cases, be regarded as a fire safety upgrade. Although this approach is not discussed in Approved Document B, it appeared in some drafts of BS9991 and is regarded as appropriate by many fire safety professionals. Nevertheless, this type of use of Automist must be reviewed by Building Control and often Fire and Rescue on a case-by-case basis.
As a general guide, if Automist is used in lieu of a lobby door, it should be installed to cover any rooms that are separated from the communal corridor outside by only one fire door. Given that the flat does not have a hallway or lobby, this usually means protecting an open plan living area.
As with other layouts, section 0.16 of Approved Document B tells us that innovative fire suppression solutions like Automist can be used as a compensatory feature in flats provided that they have been designed for residential use and have been appropriately tested. The testing of Automist is presented in some detail in the Automist Technical Guide.
So will I be allowed to remove a lobby?
As we've said, sometimes the standard layouts for flats in England and Wales prove unattractive for either commercial or aesthetic reasons, and the presence of lobbies is no exception. In many cases, Automist may be able to slow down or halt the progress of fire and smoke into communal escape routes more reliably than a fire door, allowing a lobby to be safely eliminated. Because the building regulations are not prescriptive and allow both alternative layouts and the use of devices like Automist, you can in principle create such layouts, as long as they are safe. However, as with any non-standard layout, you should discuss the proposal in detail with your building control officer before starting your project. Coming up with a proposal that is demonstrably safe may need the support of an independent Fire Engineer and for some properties, removing lobbies may in the end not be deemed appropriate.
View some case studies - Automist used to enable the removal of a lobby.