What the second staircase guidance means for the industry

In December 2022 the government announced that all new residential buildings over 30m would require two staircases. During consultation, evidence presented by and pressure from a number of industry bodies persuaded the government that the height threshold should be lowered.

Consequently, in July 2023 it was confirmed that the proposal had changed and all new residential buildings with a habitable floor level over 18m will now require a second staircase. At this time, the provisions to support the firefighting function of a second core were not stipulated, including lift type and size, lobbies, and ventilation to the cores.

In October 2023 secretary of state Michael Gove announced that there would be a 30-month transition period from the date that the second stair policy changes are formally published within Approved Document B. 

During this transition period any new Building Regulation applications for buildings over 18m could either follow the previous guidance or the new second stair policy. After the 30 month date, the beginning of October 2026, then all new applications have to include a second staircase. Gove also stated that any 18m+ residential buildings with a Building Regulations approval would have 18month to be sufficiently progressed on site otherwise a new application would be required.

The second staircase policy has taken nearly two years to develop but it was important that the government made certain that the final height threshold decision and the wider policy provisions where robust and supported by evidence. The analysis work seemingly considered similar policies in other countries, the supporting evidence presented by the industry and the impact of the policy on housebuilding and housing provision. 

It is clear that the policy relates only to the provision of a second stair and not a second fire-fighting shaft or the absolute requirement for the inclusion of evacuation lifts

With the policy now finalised and the Approved Document B guidance published on Good Friday it is clear that the policy relates only to the provision of a second staircase and not a second fire-fighting shaft or the absolute requirement for the inclusion of evacuation lifts.

Instead the guidance states that were evacuation lifts are provided that they should be provided in an evacuation shaft which includes a protected stair, the evacuation lift and an evacuation lift lobby. This will be to the disappointment of some industry bodies, including the National Fire Chiefs Council (NFCC), who have been campaigning for the inclusion of such additional provisions.

NFCC published an opinion paper in February of this year recommending the provision of two fire-fighting cores which included firefighting and evacuation lifts in each. This was to provide resilience in case of redundancy of any part of the egress and firefighting solution. The NFCC opinion paper also includes guidance on lobby arrangements and smoke ventilation design strategy which has a significant impact on core layout design and nett to gross.

The Approved Document B guidance does not provide specific design solutions that would therefore be deemed to be compliant, that will be down to the designers and developers to interpret. Smoke ventilation of corridors and lobbies is required and it is stated that corridors serving two or more storey exits should be divided by a self-closing fire door.

Height measurement is another consideration, the measurement for a fire fighting shaft as set out in Approved Document B is not the same as that set out in the Higher Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023. 

We must remember that the new policy is the minimum requirement under the legislation and some developers may well exceed the standards

The former states that the measurement is taken from the fire service vehicle access level and the latter from the external ground level. Anomalies like this may well cause some level of confusion on buildings that are being designed to be close to the 18m threshold height, or on sloping sites, or where buildings or cores are connected. We also await the issue of the new version of BS 9991 to see if the guidance in that will align with the ADB guidance on second stairs.

We must remember that the new policy is the minimum requirement under the legislation and some developers may well exceed the standards and choose to include evacuation lifts and a second firefighting shaft.

We may well see the comments from the Fire and Rescue Service at Gateway 1 advising that the minimum requirement if proposed is not adequate. 

High rise residential developers can confidently proceed with projects and housing supply numbers will therefore continue to increase over the coming period.

The NFCC opinion paper also reminds us that considerations should not just relate to the Building Regulations but also occupation legislation. Presumably therefore also the Fire Safety Order, the Building Safety Act and The Building (Higher-Risk Buildings Procedures) Regulations 2023.

After a long period of hiatus, with the policy now formally published, high rise residential developers can confidently proceed with projects and housing supply numbers will therefore continue to increase over the coming period.

But it may not be that simple if the Fire and Rescue Service request greater provision than in Approved Document B, fire engineers develop fire strategies which go beyond the minimum requirements in the guidance and of course in London, evacuation lifts are required by the London Plan.

So, it seems likely that we will see many buildings going beyond the new ADB guidance and given the same considerations we will see few 18m+ buildings being started in the next 30 months with only one staircase.