Everything you need to know about Open Plan Layouts – Part 1 of 2

Open plan living is becoming increasingly popular. It can boost room size, let in more light and add value to your home. But whether it’s an open plan kitchen/diner, a loft conversion or split-level ground floor, it’s essential you check what building regulations your project will need to pass as it could put constraints on your designs. You might require planning permission, particularly if load-bearing walls need to be removed and, if you’re planning a loft conversion, or opening up an enclosed staircase and need to create a fire escape route, you’ll need specialist fire suppression advice from a Fire Engineer.

So whether you’re a homeowner, landlord, architect or interior designer, we’ve put together a guide to everything you might need to know about making your home open plan.

Types of open plan layout:

An open plan layout is where you combine one or more rooms into a single, open space, and means your project will have larger rooms with few or no internal dividing walls. There are three types of open plan layout:

• Type 1 – This is where your kitchen is combined with another habitable room, like a living or dining room, but it’s not on the fire escape route, and there are no bedrooms off the open area
• Type 2 – This is where the staircase or fire escape route is combined with a habitable room, like a living or dining area, but your kitchen is separate. You see this with flats where bedrooms are accessed via the living room.
• Type 3 – This is where you have a kitchen and possibly other rooms open to the main escape route from the property. An example is when your main staircase passes through a kitchen/diner.

All open plan layouts must comply with building regulations, even when planning permission isn’t required, and it’s worth remembering that the more open the layout, and the higher the property from the ground floor, the more restrictions there will be.

Types of open plan layout that are allowed:

The building regulations are written in very general terms, but assuming your property has the correct number of fire doors and escape windows at the first floor and below, the following layouts are allowed:

• Type 1 layouts will normally be allowed.
• In two storey houses (or two storeys plus a basement) you’ll also be allowed type 2 and 3 layouts. However, on the Isle of Man, you’ll need a fire suppression system.
• In three storey houses (or three storeys plus basement), a type 2 layout is allowed in England and Wales if you fit a fire suppression system in the open area. You don’t normally need this in the upper storeys, but you will need a fire door between the ground and first floor. You might be allowed a type 3 layout, but you’d need a report from a Fire Engineer and, in most cases, an alarm system and other fire safety measures.
• For houses of four storeys and above, you’re likely to need a fire suppression system throughout most of your property, or a second fire escape staircase from the upper floors. A type 1 layout will normally be allowed, but as with three storey houses, you’ll need specialist advice from a Fire Engineer.
• In flats no higher than the first floor, you should be allowed to create type 2 or 3 layouts, though you may have some constraints put on kitchen location.
• In flats above the first floor, you’re allowed to create open plan layouts if you install a fire suppression system, but this guidance is still being developed, so you may need to consult a Fire Engineer or a Building Inspector for further advice.
• In some buildings, open plan flats must have a lobby or hallway between the front door and the open plan area. This is a key safety feature so it’s best to assume it has to stay, though it’s always worth discussing with a Fire Engineer.

If you’re ever unsure whether your project complies with the regulations, a quick call to your local council’s building control team or a private approved inspector, will clarify.

Open plan layout approved

What about Scotland and Northern Ireland?

In Scotland and Northern Ireland, guidance as to what open plan layouts are allowed is either very limited or non-existent and you won’t be able to use a private sector building control Inspector. You should expect to discuss your plans with your local authority building control team at an early stage, and, if they agree to your project in principle, be ready to bring in a Fire Engineer.

Loft Conversions:

When you convert the loft of a two-storey home, building regulations advise you install a protected escape route to allow people on the upper floors to escape at the ground floor, or from first floor windows. It’s protected to ensure they can escape without being exposed to smoke and heat from a lounge or kitchen fire below.

Unfortunately, this protected escape route won’t work if fire doors are left propped open or worse, homeowners opt for a cheap solution – the dummy wall. This is where a protected escape route corridor is built, Building Control sign it off and the homeowners remove the dummy wall shortly afterwards. The outcome is not just poor fire safety, the removal of a dummy wall poses a serious threat. BRE (Building Research Establishment) ran a large number of tests representing television fires in loft converted houses and found the following:

• Conditions in the room of origin (lounge) always became lethal after 20 minutes.
• With the lounge door open or an open plan layout, conditions also became lethal in all other open spaces of the house.
• With the lounge isolated by a closed door, tenable conditions were maintained throughout the rest of the house.
• Sprinklers in the lounge restored survivable conditions throughout the rest of the house.
• The life safety benefits of linked smoke alarms were clearly demonstrated.

Compartmentation or fire suppression is the key to survival, but while it’s easy to remember not to prop open a fire door, or ensure they feature spring closers, the compartmentation ideal isn’t realistic in contemporary open plan layouts like loft conversions, especially if there are dummy walls. However, UK regulations allow the use of fire suppression options, like sprinklers, to compensate for this.

Everything you need to know about Open Plan Layouts – Part 2 of 2