garden (snooker) building, how to meet regs

[browfish]

I am planning to build a snooker room at the bottom of the garden. The plan is to build this as a glorified shed but due to the size will need to meet builing regs. The building will be about 8m x 5m internal area so will exceed the 30sqm limit, and i also hope to build it closer than 1m to my boundary (approx 500mm to allow access for maintenance only.

I am sure i will come up with many questions as i go through the project but the first 2 things are

1 - what would you construct the foundations from to meet building regs. will a slab have to meet the same regs as a house/extension? Timber is probably cheapest but not sure this is best for a snooker room. Solid slab probably the most expensive especially as being at the bottom of the garden would need a lot of muck to move and expensive concrete pumping. I am not scared of some hard work and have hand mixed some big slabs in teh past but this might be a bit much in one day. Should i go strip foundations with block and beams screeded?

2 - what would you construct the walls from. Was thinking timber frame but again what would be needed to meet regs. i understand the timber can be varnished to make it fire retardant close to the boundary. I have built masonry cavity walls before but this would move into the realms of planning required too wouldn't it?

Any help appreciated so thanks in advance.

 

[big-all]

do you have planning permission
https://www.planningportal.co.uk/info/200130/common_projects/43/outbuildings

 

[browfish]

No i shouldnt need planning. I will stay below the 2.5m height and it is less than 50% of the garden

 

[big-all]

ok mind its 2.5 from the natural ground level [adjacent to ]it covers at the highest point

 

[frutbunn]

As the building is over 30 sq m then it will need to be constructed to B regs. Foundations etc will be treated no differently to any other building. A raft type found is OK but your LA may require a structural engineers design, some BCO's may agree an over engineered approach for the raft but this depends on the LA/BCO.
As far as building within 1m of the boundary you are only allowed very small unprotected areas or combustible material, the amount you allowed increases with the distance from the boundary. Please note the boundary can be taken as the centre line of any public road, footpath, canal etc immediately bordering the boundary.
In addition the wall will require half hour fire resistance, Masonry construction will satisfy this requirement, this will make no difference to your PD rights. If you use timber construction on this boundary it will need to be treated with an intumescent coating to reduce the surface spread of flame, fire resistance can be achieved internally with 12.5mm plasterboard and externally by applying a silica type board prior to the timber cladding. You may be able to buy pre treated timber for external use but its not something I've ever looked into.

 

[PTS2]

It's an interesting question which I did have a look at recently when I was going to build a shed.
I think definitely Part A Structure. The Approved doc actually makes reference to outbuildings (eg thickness of walls) so I think this is a definite.
As the regulations say anything within 1m of the boundary has to be non-combustible or something, this implies Part B (fire) is also in play.
Part P is always required even if you put a socket on a fence.
Fortunately part L (Thermal stuff) doesn't apply as you are under 50sqm.

When you find out then let us know

 

[frutbunn]

Fortunately part L (Thermal stuff) doesn't apply as you are under 50sqm.

I would apply Part L as this exemption does not apply to dwellings.

 

[PTS2]

I'd be interested to see the law which defines the described outbuilding as a dwelling.

 

[browfish]

Thanks for you input.
I would certainly want to insulate the building as i wouldn't want to play snooker in the cold in the winter and wouldn't want heating costs to be extortionate. I would need to keep it above say 10deg c at all times to avoid damage to the table. so i would probably aim to comply with park L anyway. As i would prob want the space to heat up quickly when i use it, i guess it would be better to put the insulation above the slab rather than below to create a heat sink but heat up slower. How would you build the foundation. I am thinking strip for a treated timber frame. How big should this be? guessing i dont have to do 600x600 1m deep like i did for my extension which had to take 2 storeys. Also how would you build the inner slab? 100mm hardcore, 100mm concrete, DPM, 100mm insulation?, 75mm screed? Do you have any links to these details and also the timber frame construction?

 

[NickFraser]

How did those all go mate? What foundation construction did you go with in the end? And what roof construction did you go with to accommodate the span?
Building a snooker room myself at the end of the garden. Cheers, nick