Part O guarding Vs Part K Escape Vs Part B Fire Safety

[Dave Jones]

Sure this is going to catch a few unawares.

 

new Part O (overheating) states:

Any guarding to be sized to prevent the passage of a 100mm sphere, to be 1.1m high from floor level, to be not easily climbable and to be capable of resisting at least the horizontal force given in BS 6180:2011.

 

Park K states: "section 3.1 At Opening windows except roof windows in loft extensions, see approved document B1" max height 800mm

 

Park B states "section 2.10 bottom of opening area is a maximum of 1100mm above floor".

 

NHBC also muddies the water, they say you can ignore Part O guarding heights if you do not rely on windows for heatloss (MVHR). also they introduce a tolerance for guarding of 100mm lower.

 

https://www.nhbc.co.uk/binaries/content/assets/nhbc/tech-zone/nhbc-standards/tech-guidance/6.7/tg-6.7-20-guardingconsiderations.pdf

 

So there seems to be no way to get around guarding and passing regs.

 

Height from Floor            Part O    Part K     Part B

    800mm                         FAIL       PASS       PASS

    900mm                         FAIL       FAIL         PASS

   1000-1100mm               PASS     FAIL         PASS

   1200mm                        PASS     FAIL       FAIL

 

Edited September 3, 2023 by Dave Jones

[ProDave]

Ask your BCO what height he wants is. 

[Dave Jones]

BCO is ok in fairness, its the warranty inspector who is anal about every little thing. Probably end up with guarding and remove it after the final visit.

[Big Jimbo]

Thats what i am intending. @Dave Jones I was doing my own Part O calcs. I couldn't find a way to make it work. All my windows open to meet ventilation. On my upstairs windows, i intend fitting them at about 900mm from the floor, and guarding them to exactly 1100mm. Once passed out, i will remove the guarding. 

[SteamyTea]

On 03/09/2023 at 08:07, Dave Jones said:

capable of resisting at least the horizontal force given in BS 6180:2011.

What is that force specified?

[Dave Jones]

1 hour ago, SteamyTea said:

What is that force specified?

 

3 jedi's and an ewok.

[ETC]

I really can’t see a problem.

Windows need to be guarded where the opening sash is less than 800mm from a floor.

An EEW has a range of between 800mm and 1100mm from the floor to the underside of the opening sash.

Have your cill height at 1000mm and make the window opening suitable for the required ventilation.

 

Can someone explain it to me please?

[ETC]

[Dave Jones]

in a nutshell a window of 1000 fails part O guarding, 900 fails part O and K per original post.

 

There is no combination that doesn't fail either O, K or B.

 

It's a right dogs dinner.