Open Plan - The Big Picture
You won’t need Intelligent Mist to achieve some more limited types of open plan layout, but for the best use of space and the biggest impression, you’ll want to combine hallways into living areas, and make a feature out of your staircase rather than boxing it into a dark corridor. To achieve those things when any part of your property is above first floor, the building regulations require you to use a fire suppression system like Automist.
Mouse over the different room combinations to find out which combinations you’re allowed and which ones require Intelligent Mist.
Three-storey Open Plan Houses
In houses of 3 storeys, or even three storeys and a basement, you’re generally allowed an open plan staircase on the ground floor, provided you fit fire suppression to cover the open plan room. This ground floor room normally can’t include a kitchen, although sometimes Building Control will permit this – or other variations – based on a short report from a fire engineer. If you’re simply combining a living room with a staircase, you should be able to use the Automist Registered Details for easy approval with any local authority, provided you meet their standard requirements regarding fire doors and escape windows.
Open Plan Flats
In an open plan flat, installing Automist Smartscan should allow you an open plan kitchen-diner-living area if you want it, with the bedrooms opening directly on to this open plan area. However, you might be asked for fire suppression throughout the whole flat. This is more expensive than just installing in a single room but has the advantage of easy approval from any local authority in England, Wales or Scotland through the Registered Detail EWS534. If Building Control are prepared to accept a report from a fire engineer, you may in some cases be able to reduce the coverage to just the open plan area.
If your flat is part of a block that’s more than seven storeys high, we recommend that you double check the approvability of your project with your Building Control provider.
Avoiding escape stairs in taller houses
New or converted four storey houses (for example after a loft conversion) must have two separate escape routes between the upper floors. For example a house with ground, first, second and third floors must have two separate staircases between third and second floors. Houses not able to comply with this requirement must fit a fire suppression system such as Automist Smartscan throughout.
Is it worth installing a fire suppression system to avoid the extra staircase?
Although the cost of a whole-home Smartscan system can be considerable, it’s important to account for the space lost to an additional staircase inside the building. In London, high prices mean that Automist Smartscan will often add value to your home compared to the staircase option.
Over two storeys, the space lost to an internal stair is roughly 3.5 to 4.6m2 (more if you have high ceilings). At London prices of £6000/m2, this extra staircase effectively destroys a floor area worth (in 2017) £20 000 to £27 000. Even a large Automist Smartscan installation would normally be less expensive than this. Additionally, installing Smartscan also eliminates any costs in building the secondary staircase with an enclosure and fire doors around it.
If property prices were to rise in future as they did from 2012 to 2017, our example prices could rise by 50% from £6000/m2 to £9000/m2 in five years. The calculation then becomes even more stark –an investment of (say) £18 000 in Automist Smartscan today might return £30 000 to £40 000 in gained floor area.
Building a new home or an extension more than 45m from the road?
If any part of your building is more than 45m from the nearest point that a fire appliance could get to, part B5 of the building regulations will take issue with your project. Luckily, there’s a solution. British Standard BS9991 allows this distance to be increased, possibly as far as 90m, as long as a sprinkler system is installed. BS8458, (which post-dates BS9991) indicates that watermist systems can be used for this purpose and outlines the consultation procedure.
What does this mean for me?
If your extension lies partially or entirely outside a 45m radius from the nearest point on the road, your Building Control Officer will probably require you to provide Automist Smartscan suppression throughout any affected rooms. The logic will be that the changes to the dwelling must make it no less safe than before.
If any part of a new build lies outside the 45m radius, you will need Automist Smartscan throughout the building, protecting all the main rooms.
Because there are some differences between BS9991 and BS8458 on these issues, you should make absolutely sure that any approvers are agreed on Automist Smartscan before proceeding with the project.
Talk to Us
Want to discuss specifics? With hundreds of Automist systems installed, there's a good chance that we've seen a situation like yours before. We'd be delighted to talk to you: give us a call, or send project details through our contact form.