Self-contained flats which guidance applies,

[Tom Sutton]

A house converted into top-floor maisonette (2nd and 3rd floors), self-contained flats in basement, ground and 1st floors, which guidance applies, Lacors or ADB?

The planning portal says,

?   Planning permission is required
?   Conversions of properties require approval under the Building Regulations.
?   You may need to consult the Fire Service regarding issues relating to fire escapes.
?   The Housing Act 2004 requires that sub-divided buildings meet standards and houses in multiple occupation are licensed. Read more about the Housing Act 2004.

ADB B3 7.9 and 7.10 applies but does the rest, only apply to purpose built flats, consequently should you use Lacors?

[kurnal]

Too many variables to answer Tom.
Is it in England/Wales? If so:
The Building Regs only apply at time of conversion of a building into flats / maisponette. They can be enforced by the Building Authority for a year after completion.
For existing buildings the Housing Act will apply and the RRO may apply if there are communal areas.(not forgetting article 31 of course)
What is the standard of compartmentation? If it is not to the standard that would be applied under Building Regs post 1991 (the obvious starting point for a fire risk assessment under either legislation) then it may be appropriate to use the  Lacors guidance (which  applies to HMOs and may be used for existing buildings as a basis for a fire risk assessment under the RRO (if required) or assessment under the Housing Act.) But similarly other guidance may be used- eg BS9991 or the LGA guidance.

Thats how I see it Tom.  

[Tom Sutton]

Thanks Kurnal,

It is in England and I fully accept building regulations, also the Housing Act will apply, because it applies to all housing and the RRO will apply.

I am talking about a four storey house being converted into self-contained flats which is not a HMO and it is decided that ADB will be used as opposed to BS9991 or BS 7974 and LGA guidance is for purpose built flats.

Now I have to apply ADB and I accept ADB B3 7.9 and 7.10 applies but it's trying to apply B1 to this project.

If it is a new build or an extension then it is relatively simple but a conversion is a different matter because ADB B1 assumes you have the layout of purpose built flats, a front door opening onto a protected corridor leading to a protected stairs, which you do not have in a conversion. It appears the MoE strategy looks first for an alternative escape; if not available it goes for an enhanced escape route, with limited travel distances.

ADB B1 could be applied to the layout of the flats but not the common areas. Lacors only look at the common escape route and not the layout of the flats.

It looks like one solution is to use both guides and cobble them together?

[Mike Buckley]

It seems to me that you are trying to change the guidance to fit the layout, rather than change the layout to fit the guidance.

[kurnal]

I am talking about a four storey house being converted into self-contained flats which is not a HMO and it is decided that ADB will be used as opposed to BS9991 or BS 7974 and LGA guidance ..............

If it is a new build or an extension then it is relatively simple but a conversion is a different matter because ADB B1 assumes you have the layout of purpose built flats, a front door opening onto a protected corridor leading to a protected stairs, which you do not have in a conversion. It appears the MoE strategy looks first for an alternative escape; if not available it goes for an enhanced escape route, with limited travel distances.
ADB B1 could be applied to the layout of the flats but not the common areas

First question- in a conversion can you achieve the requisite 1 hour compartmentation between floors and between flats in order to support a stay put strategy? If not its an HMO with a full evacuation strategy (unless you compensate in another way).
Second question- unrelated to the first- are all flats and maisonettes served by the same common stair? As the top  floor is given over to maisonettes can enhancements be made within the maisonettes to make them equivalent to a flat on the third storey? Have seen this done often in the past.
Third question - are all flats served by the same communal staircase, what standard of protection can you provide to the staircase? Single flat entrance door or lobby?

If you have an evacuation strategy an AOV in the stairs controlled by and heat detectors in the flats and smoke detectors in the stair with an evacuation taking  place if a heat detector in a flat activates this may be seen as an acceptable compensation for other weaknesses under ADB ?

[Tom Sutton]

Mike you could gut the place put another staircase in and lobby them to follow the guidance in ADB vol 2 but isn?t that little OTT.

Kurnal,
Q1 It would be very unlikely to be able to achieve 60 minutes compartmentation.
Q2 One common staircase and yes you could upgrade the maisonette.
Q3 As far as I am aware single flat entrance doors.

AOV is a consideration under ADB and so is an alternative MoE, you could use an external escape stair. If there was an unserviceable one would insist it renovated or accept an alternative under ADB vol clause 2.16 page 23.