Compensatory measures for open plan kitchen/living room

[Guest Peter G]

First of all, thank you in advance for your responses. I would greatly appreciate your expert suggestions or experiences on this matter.

We are renovating the ground floor of our 1930s three-story house. The house already has a loft conversion, which we are not altering.

The council is objecting to our proposal and is requiring us to add a wall that we had removed to create an open-plan design—this was a key aspect of our renovation.

To be specific, we have an open-plan kitchen/living room that is connected to the rest of the house via the stairs. We plan to install a sprinkler system throughout the ground floor, fire-rated (FD30) doors for all bedrooms, an automatic fire detection and alarm system (LD1), and an escape window in the front bedroom on the first floor.

The council has opposed our plan, citing non-compliance with points 2.23 (b, c) in the Part B regulations document, which state:

b. Provide a fire-resisting partition (minimum REI 30) and door (minimum E 20) to separate the ground storey from the upper storeys. The door should allow occupants of the loft room access to a first storey escape window.

c. Separate cooking facilities from the open-plan area with fire-resisting construction (minimum REI 30).

We are willing to add a partition with a fire door in the stairs to comply with point b, but I’m struggling to understand how we can meet point c while maintaining an open-plan kitchen/living room. To me, point c seems to conflict with the principles of open-plan design.

I am consulting with my architect, but I would greatly appreciate any expert suggestions or experiences you can share. Thank you!

 

[AnthonyB]

It's not uncommon in situations like this for residential sprinklers to form part of a solution as well as stove guard auto cut outs - it does depend on the size of the premises & layout. I've also seen smoke control (Automatic Opening Vents) used inside dwellings to compensate as well. You would be best consulting with a Fire Engineer

[Guest Peter G]

Thank you for your response.

The house is a normal 1930's semi detached house. See attached images for the layout. We are only changing the ground floor. 

We recently consulted with a fire safety engineer who prepared the following points for review by the council. These are the measures we have already planned:

(i) Installation of a single, unified automatic fire detection and alarm system (Type LD1 - minimum Grade D2) to BS 5839-6:2019+A1:2020 throughout the entire dwelling, with simultaneous evacuation of all floors when an alarm is triggered. This includes detection in all habitable rooms and circulation spaces, interlinked and mains-powered.

(ii) Installation of an automatic fire suppression system (e.g., a domestic sprinkler system to BS 9251:2021 or an equivalent proprietary mist system to BS 8458:2015) throughout the open-plan areas on the ground floor, including the kitchen, living, and dining areas.

(iii) Enclosure of the stairway on the first and second floors with 30-minute fire-resisting construction and FD30 doors (except in WCs), with no requirement for self-closers. The walls between bedrooms/habitable rooms and the landing/staircase inherently enclose the stairway.

(iv) Enclosure between the reception room and the open-plan areas on the ground floor, using 30-minute fire-resisting construction and an FD30 doorset—again, with no self-closer required.

(v) A window suitable for escape will be provided in the front bedroom on the first floor.

As you can see, we are already implementing an iMist system and other fire safety measures. However, building control is still not satisfied and has not approved the plan, even after this report from the fire engineer. Their main concern is that point C in the Part B regulations document is not being addressed.

This is why I am seeking your expertise. If we add a new wall to separate the kitchen on the ground floor, it will compromise the open-plan design, which is the core reason for our renovation. I am not trying to avoid any safety measures, as demonstrated by the comprehensive steps we are already taking to ensure the safety of our home.

Thank you again for your help.

[AnthonyB]

Approved Document B is not a regulation, it is just one way of meeting the rather broad functional requirements of the Building Regulations and is not a mandatory document - you can use other methods:

"The fire safety requirements of the Building Regulations will probably be satisfied by following the relevant guidance in this approved document. However, approved documents provide guidance for some common building situations, and there may be alternative methods of complying with the Building Regulation requirements. If alternative methods are adopted, the overall level of safety should not be lower than the approved document provides. It is the responsibility of those undertaking the work to demonstrate compliance."

As what the fire engineer proposed is along the lines of what is often accepted I would suggest you request a determination:

https://www.gov.uk/guidance/building-regulations-determinations