Alternative escape up an external Spiral staircase and across a roof???

[chillbay]

Hello All
First post so please be gentle…

I have been asked to have a look at a building in London. To give you a rough idea, the building is approximately 3o meters end to end. At the front of the building there is a protected staircase which serves all 5 floors.

To the rear of the building 1st floor upwards, there is a spiral staircase which is accessed by the fire exit on each level. There is no way down at this stage at the rear so you have to travel upwards. When you reach the top level there used to be access into the adjacent building (local agreement) but now this access has stopped.

Still at the top of the spiral stairs, you find a vertical ladder which gives access to the roof, once on the roof, walk to the front of the building there is access back into the front staircase, however there is a keypad entry, I guess to stop break-ins. Staff levels are at around 250

I have done a bit of research and this scenario seems to be quite common in places like London. I have looked at travel distances, upgrading the internal protected staircase, upgrading the alternative route over the roof. The whole building is covered by sprinkler protection and detection systems.

Can I have some of your views on this?
Looking forward to your contribution   

[Midland Retty]

Hi Chillbay

Welcome along!

What is the building used for?

Clearly the means of escape is currently inadequate. Travel distances to hit a protected staircase are excessive, and alternatives (ie roof / adjacent premises) are no longer available, and in any event the use of vertical ladders for means of escape in any case is generally frowned upon and can only be considered for small numbers of staff.

Without looking at providing suitable alternatives exit routes (which sounds very impractical from what you have said) it may be worth looking at the recommedations in British Standard 9999 - a word to the wise unless you have had any input or experience of applying, interpreting it, then it may be best left to someone who has.

BS9999 needs to be applied in full, but it may allow you extended travel distance based on risk profiles, height of ceilings, level of AFD and sprinklers. Again it does depend on the internal layout of the building and where you begin measuring your travel distances from.

The things that run through my mind are:-

1) Can the wayleave agreement into neighbouring building be restored?
2) Is it possible to upgrade the roof MOE (without the need to use vertical ladder)?
3) What existing precautions have I got and how do they assist with securing means of escape (ie will upgrades allow for extended travel distance under BS9999?
4) Do I need to call in a fire engineer for an engineered solution to the problem?
5) Can i form protected corridors inside the building (same concept as route on the roof but inside)

[chillbay]

Hi Middy and thanks for the welcome

It’s a difficult one, the building is used as office space and mostly open planned. The distance measured is from the rear wall to the front exit door which leads into the staircase. I don’t think the neighbouring building is an option anymore as its being developed.

The vertical ladder has a fall cage around. It sounds to me either BS9999 or and a fire engineered solution may be required. Not as straight forward as first thought…     

[AnthonyB]

Was it definitely a local agreement and not a formal easement - if the latter it's generally binding regardless of change of heart (or change of owner unlike an MoE license), I'd double check that first in case the adjoining premises are mistaken in their belief they can simply end the arrangement. If the adjacent building is being developed perhaps Building Control should be made aware of the need for access and conditions imposed?

This issue isn't uncommon as in many big cities (Liverpool, Manchester & Birmingham all have this) the means of escape requirements brought in by the OSRP in 1963 could only be met by either adjoining internal doors in the party wall, roof escapes to adjoining building stairs, and shared external stairs.

In many cases where an easement hadn't been enacted a suitable fee for granting one was the solution, but I know of one building that sits empty because of a change of owner of the adjacent building led to the license to use the adjoining external stair not being renewed.

Failing restoring the adjacent route the careful application of BS9999 and fire engineered solutions may be the only way......but only if affordable by the client...otherwise the risk of another empty building up for sale as a development site may loom...

[Phoenix]

You don't say if the building is all occupied by a single tenant or if there are different tenants.  This is quite important.  I will give an analysis based on the assumption that there is a single occupier on all levels.  Also, you do not say what the means of escape is like from the ground floor so I will assume they have at least two ways out.

First of all, let us consider able bodied people.

If a fire occurs on the ground floor then, hopefully, the means of escape on the ground floor are adequate.  Everyone else in the building will have to pass by the ground floor as they escape so, again, hopefully there is adequate protection to the internal staircase.

If a fire occurs on one of the upper levels then the people on the fire floor can evacuate via the storey exit to the internal staircase or via the storey exit to the external spiral staircase.  The people that go via the internal route are ok and the people that are forced to use the external route should have the ability to re-enter the building at any other level (upwards or downwards) and make their way to the internal staircase and escape via that protected route.

No problem for able bodied people (provided that they are given the means to re-enter the building and access the internal staircase).  Everyone will need to be instructed to use the main internal staircase in an evacuation unless they are unable to do so because of the location of the fire, in which case they should use the external spiral staircase to access another level through which they can escape.  Another assumption here is that the main internal staircase is of an adequate size to accommodate the occupants of the entire building. 

There are quite a few assumptions above.  If any are incorrect, come back with more information.

Let us now consider people with mobility impairments that make them unable to use the external spiral staircase.

On the assumption that the external spiral has not been designed to provide disabled people with sufficient space for refuges, people with impaired mobility will only have one way to go if a fire breaks out and that is towards the internal staircase.  You say that the building is 30m from front to back.  There is no way that travel distance recommendations can be met, BS9999 or not, so it can only be concluded that none of the upper floors are safe for disabled people to use.

This may or may not be a disaster for the occupiers.  The DDA is reasonable in such circumstances and alternative arrangements may be possible.

Are all my assumptions correct?  If not, we need a re-think.

Stu

[chillbay]

Hi AnthonyB and Phoenix

I will delve further into the agreement, there may still be hope there,

The building has only one tenant, there are 2 means of escape from the ground floor, there are no mobility impaired staff on the upper floors, so your assumptions are spot on!

At present it is not possible to re-enter at the rear via the spiral stairs, building security I guess, but I am sure there is a possibility that this could be overcome, alarms etc.

Thank you all for your invaluable insight