Since the terrible Grenfell tragedy, there has been an increased focus on fire safety when it comes to residential buildings. Indeed, the Building a Safer Future report from Dame Judith Hackitt provides much-needed recommendations for how the safety of residents can be enhanced.
However, even though the response to the report was generally positive, some organisations have highlighted shortcomings in the classification of High-Risk Residential Buildings (HRRB).
The new regulatory framework focuses on multi-occupancy HRRBs that are 18 metres or more in height, but many authorities suggest that this definition is too narrow. There are calls to include all residential buildings over 11 metres and those that house vulnerable residents, for example, student accommodation and residential care homes.
At Innovation Fire Engineering, we believe that hotels should also fall within this category.
For HRRBs with a top floor height over 18m there is a requirement for materials that form part of the external façade (apart from the excepted items) to achieve Class A2-s1, d0 or Class A1. Hotels are specifically excluded from the HRRB category type and are therefore also excluded from requiring these materials.
Additionally, if the top floor height of the hotel is under 18m and the external wall is more than 1m from the boundary, there is no recommendation in relation to the classification of the external wall.
Certain groups of buildings must be provided with sprinkler protection if they have a top floor height over 30m. These include residential, offices, shop and commercial, assembly and recreation, industrial and storage. However, the current guidance specifically excludes hotels from the requirement for sprinkler protection, even if the top floor height of the building exceeds 30m.
Concerns about this guidance
Our first concern is that hotels have a lower level of compartmentation than residential flats and no ventilation requirements to protect the escape routes due to the ‘simultaneous’ evacuation procedure.
Secondly, the ‘simultaneous’ evacuation for a hotel is generally double knock to avoid people being evacuated unnecessarily. Unfortunately, the time to alarm with a double-knock system could be over five minutes. You then need to account for the pre-movement time and the travel and queuing time to reach the relative safety of a staircase enclosure or ultimate safety outside the building. Consider also that hotel guests may be asleep when the alarm sounds and are likely to be unfamiliar with evacuation routes.
All these factors mean that pre-movement time for hotel occupants once the alarm has sounded can be more than 20 minutes.
By comparison, an office contains only people who are awake, and so the pre-movement time for occupants is a maximum of two minutes. In general, people in an office can reach a place of relative safety within three minutes of the alarm sounding, with most occupants in a place of ultimate safety outside the building within five minutes.
When you consider the difference in evacuation times, it seems incredible that an office building with a floor height above 30m is required to have sprinkler protection, but a hotel isn’t.
Why are the guidelines more stringent for buildings where occupants would be awake if a fire occurred than for buildings where they could be sleeping?
The government has recently held a consultation, and it appears that they are going to recommend that buildings with a top floor height over 11m are provided with sprinkler protection.
Unfortunately, we do not yet know how wide-ranging the categories of building will be for the new recommendation, but we firmly believe that hotels should be included.
What’s more, we don’t think the current regulations for the external façade of a hotel matches the risk, considering the occupants are unfamiliar with the building and may be asleep when a fire occurs. Therefore, we advise our clients to use materials with class A2-s1, d0 or Class A1 for the external façade of hotel buildings with a floor height greater than 4.5m (or 11m where 100% perimeter fire service access is provided).
About Innovation Fire Engineering
Innovation Fire Engineering is an award-winning, independent company, specialising in fire safety. Our team of experts provide innovative fire engineering strategies for contractors, developers, architects and consultants across England, Scotland and Wales. We are focused on designing fire strategies to make buildings safe, so disasters like Grenfell don’t happen again.
If you would like to discuss a project or have any questions about fire engineering solutions, then our friendly consultants are happy to help. Call us on 0113 4605906 to find out how we can support you.