The Brew Cabin

Posted: **Tue Nov 20, 2012 1:46 pm**

Hello all I am looking into the possibility of putting a 1 storey extension on-top of our existing extension and have heard the planning laws have been relaxed, is this true and ballpark figure would be great current foot print 3600x5600mm with a flat roof think we would need to juice up the footings also

Thanks in advance

Peter

Posted: **Tue Nov 20, 2012 4:19 pm**

If built recently it may be possible that your footings are 1m deep and acceptable to use as they are. Otherwise its hassle

Posted: **Tue Nov 20, 2012 4:27 pm**

generally all 2 storey extensions need planning
what size cavity is the lower one?
all cavity work now must be 300mm overall
LLL

Posted: **Tue Nov 20, 2012 4:59 pm**

The lower cavity is only about 150 sounds like it could be a pain but cheaper than moving .....
How do you increase the upper walls cavity, from the existing footings? which would need to be increased ?

Posted: **Tue Nov 20, 2012 5:35 pm**

exoticpete wrote:The lower cavity is only about 150 sounds like it could be a pain but cheaper than moving .....
How do you increase the upper walls cavity, from the existing footings? which would need to be increased ?

Suppose you could cantilever over the internal block so the outer-wall matches?

Posted: **Tue Nov 20, 2012 7:02 pm**

2 pad stones and a steel along one side then 2 further steels cleated to that running the other way at 100mm cavity

failing that you can build at 250 but you will then have to add a further 50mm stud wall filled with celotex inside your block work
we just had to do this at the flat conversion and they were very insistent on it
LLL

Posted: **Tue Nov 20, 2012 7:17 pm**

Surely solid wall with internal insulation is the cheapest way to go, i would prefer dot and dab insulate with a plaster board finish

Posted: **Tue Nov 20, 2012 7:17 pm**

not sure if poss, but could you build new internal skin in timber stud work and build brick skin on outer skin.

Posted: **Tue Nov 20, 2012 9:39 pm**

sounds like it can be done one way or another many thanks just need to see if the bank will come to the party,extending is the new moving ..!

Posted: **Tue Nov 20, 2012 11:12 pm**

local patios and driveways wrote:Surely solid wall with internal insulation is the cheapest way to go, i would prefer dot and dab insulate with a plaster board finish

you obviously havent done any double extensions on top of existing ones lately Dan

they have the hots for insulation right now,and will not accept any solid walls
so it would have to be 250 cavity + 50mm celotex inside studwork
this info is as of last friday
the days of just dot and dabbing the blockwork are long gone mate
LLL

Posted: **Wed Nov 21, 2012 7:23 am**

Im doing one job right now.. But... Admitedly its an office at the end of a garden

Bco is happy with solid wall internal insulation there. Teach me.

Posted: **Wed Nov 21, 2012 7:40 am**

is it an existing solid wall?
if so they normally accept 100mm stud and resilient bars and vapour barrier
of course the big problem is that different BCOs even within the same jurisdiction will give conflicting views
so 1 guy says 75mm celotex in the floor is ok
and the next wants 100mm
when you are looking at Â£35 a sheet it soon mounts up
warm deck flat roofs are another favourite of theirs
LLL

Posted: **Wed Nov 21, 2012 9:17 am**

first off its only a consultation about the planning nothing legal has changed

second it was only for single storey extensions

so you are going to have to get some drawings done, some building regs drawings and apply for planning,

you need to know what your footings are as well....

Posted: **Wed Nov 21, 2012 1:18 pm**

Tony, its a new build single story. So is solid wall not allowed in new builds? I admit im no expert especially compared to you who deals with this stuff daily.

Posted: **Wed Nov 21, 2012 4:58 pm**

is it a habitable space? even in sheds etc single skin is bad idea due to moisture wicking through the block.

The Brew Cabin

Extension planning