sleeping guide and purpose built flats

[jasper]

I am looking at some fra's on existing purpose built flats and while doing some research prior to assessment I have come to a bit of a stumbling block. I have looked at a couple of the premises to get an idea and they are 3-4 storey blocks of flats built approx 30 years ago, have good compartmentation to the walls and floors and fire doors to the flats and ld3 detection to flat lobbies. In the sleeping guide figure 51 ground and up to 3 upper floors shows detection (suggested) to the staircase and flats and protected lobbies or corridor, however as these are single staircase and have a travel distance from furthest flat door to staircase of 8+m then figure 54 single stair with auto ventilation should apply. The main question is which figure should be adopted as it goes with both. Also, has anyone experienced any trade-offs? i.e L3 detection as a compensatory feature for no auto vents to corridors or for lack of protected lobbies.

[Midland Retty]

Hi Jasper

Figure 51 relates to sleeping accomodation other than flats or maisonettes. A Hotel or Hostel for instance.

Figure 54 does apply specifically to flats and maisonettes and would thus apply in your scenario.

Do the blocks have any form of existing vents? Are there no natural vents in the communal areas?

[jasper]

Thanks for the reply Midland, I am still looking at the guide and have not spotted the clear definition or is it just due to the images?
The blocks have openable windows on each floor but have no protected lobbies etc. there must be thousands of these all over the country which due to 7.5m escape to single staircases will require lobbied protection and aov's to corridors

[kurnal]

I would base my report on the standards set out in ADB, 5588 part 1, CP3 Chapter 4 part 1 and any local enactments relevant at the time of constructon. Then if the original design has been tampered wth, eg opening windows sealed up or mechanical ventilation fallen into disrepair then I would recommend upgrade to the latest standards.

It cannot be reasonably practicable to apply the latest BRE thinking on common areas ventilation in flats that were built to a different strategy. Even if that basic strategy was later found to be flawed.

Sorry I have not got much time for those silly drawings in the sleeping guide and table 1 on page 55 with its crass errors. I could say the best thing to do with the sleeping guide is to tear it up into small squares and place it on a nail behind the door of the smallest room. But perhaps I shouldn't. After all it would be a bit scratchy.  

Note added later- sorry for the tetchy comments above which were on review a bit harsh. The frustrations arise from an experience of a new generation of inspecting officers (very much a minority I hope) who appear to be trying to make existing buildings fit the pictures in the guides and dont appear to be given the more rounded training in the development of building standards over the years.

[AnthonyB]

For residential I will use the LACORS guide primarily as well as Document B, rather than the sleeping guide  - depending on the structure of each property the requirements can vary from alarms everywhere to not needing anything other than single station detection to each flat - not all flats blocks built pre 1991 are going to automatically require alarms to all areas including common and from a management/human response point of view would rather go for passive upgrade and ventilation than common alarms if practicable, particularly if the existing structural protection is virtually to 1991 or later standards (even if built before then) and only needs tweaking here or there to meet current standards for stay put.

[Midland Retty]

there must be thousands of these all over the country which due to 7.5m escape to single staircases will require lobbied protection and aov's to corridors

Absolutely - there are hundreds of low rise blocks out there  of a similar layout.

The sleeping accomodation guide is of little use especially in terms of flats and maisonettes

CP3 is a good start, this will tell you how the flats should have been designed / constructed. Bear in mind that it was common place years back to have passive ventilation as Anthony points out. I find permantly louvred vents in many blocks which are designed to claar smoke from common araes and keep escape routes tennable. (CP3 talks of ventilation permenantly open to the elements)

Im wary of applying Lacors guidance in purpose built blocks, even those built pre 1991 building regs. I would be tempted to steer clear of it in this scenario. ADB would be a better bet to get a flavour of current standards vs the older ones given in CP3 , that way you can strike a balance depending on how how poorly maintained the block is and how far is needed to go to bring them up to scratch.

[dpjohno]

It is worth noting that the BS:5588 series is now obsolete. It was withdrawn on 6th April 2009. It was replaced by BS:9999 2008. 

[CivvyFSO]

It is worth noting that the BS:5588 series is now obsolete. It was withdrawn on 6th April 2009. It was replaced by BS:9999 2008. 

Welcome to the forum dpjohno.

The BS5588 series is still alive and kicking due to it still being referenced in ADB. ADB is guidance supplied whereby complaince with it assumes compliance with Building Regs, and that compliance extends to the standards referenced within it.

The planningportal people are quite clear on the subject and technical indexes still have it available for the same reason.

[wee brian]

Work has just started on redrafting 5588-1 and publishing it as 9991.

[Stinky]

BS5588 is still guidance, regardless of being withdrawn.  Same as CP3.  Its old, its dated, but it is perfect guidance to consider when undertaking an FRA.  THe key to undertaking an FRA in old tower blocks / ressy building, is to have an idea of how these buildings were designed.  Many fire fighters think they can undertake FRAs, but without knowing how these buildings were intially designed, this is where unsuitable and unsufficient reports are produced. 

Now with regards to the intial query.  Relating to AD B, BS5588 and the sleeping guide.  They all say a similar thing.  For purpose built blocks up to 4 floors above ground (G+3), you can have two flats opening onto the stair without ventilated corridors.  Flats can also open onto the stair if they have internal protected hallways, however RRO FRAs are non intrusive of flats, therefore difficult to ascertain. 

If you have four floors above ground and there is still no ventilation to corrids, unless the corridors are located next to external walls, it is unrealistic to acheive.  You need to assess the risk.  It is reasonable to assume that the increased risk of the additional floor is legligable, compared to the cost of constructing ducts or voidds to provide ventilation to the corridors.  I have an FRA of a block exactly the same (I think).  PM me and i'll send you it.