Experience….

[G and J]

34 minutes ago, Kelvin said:

Our walls are very thick for a new build. Over 400mm from the front face of the cladding to the face of the painted wall. Fortunately we didn’t have any space constraints but it still wasn’t easy getting the panels in using a tele-handler. 

We are trying to build with walls a foot thick, inside face of plaster to outside face of larch cladding.  I understand and inherently trust blockwork, (emotional based thinking) which is what we used first time, but that would require much thicker walls.

So you built your house with SIP panels?

[JohnMo]

Just worked out my front clad walls, 520mm thick in total.

[Kelvin]

 

53 minutes ago, Kelvin said:

 

Edited May 27 by Kelvin

[Kelvin]

13 minutes ago, G and J said:

We are trying to build with walls a foot thick, inside face of plaster to outside face of larch cladding.  I understand and inherently trust blockwork, (emotional based thinking) which is what we used first time, but that would require much thicker walls.

So you built your house with SIP panels?

I’ve just measured ours and they are 510mm thick as I forgot to add the 3G windows in. 
 

No not SIP. Ours walls are based on a space frame design so the basic wall itself is 300mm. We liked the look of deep reveals so it was as much an aesthetic decision as functional. 

 

Edited May 27 by Kelvin

[G and J]

Over half a metre.  Oh my word.  That would shrink our rooms quite a bit. The site is only 24’ wide. 

[Kelvin]

Actually it’s slightly worse than that as we also have an internal wall that runs the full length of the house constructed the same way as the external walls minus the window and cladding obviously. It’s 430mm thick. Our rooms could have been a lot wider had we gone with SIP walls. However they are more than wide enough as the open plan area  is 5.5m wide. 
 

[Jilly]

I’ve only used Aerogel to clad some steel. It’s surprising dusty stuff, it needs careful handling to avoid lungfuls if you need to cut it. 

[JohnMo]

2 hours ago, G and J said:

Over half a metre.  Oh my word.  That would shrink our rooms quite a bit. The site is only 24’ wide. 

Remember that's only external walls, internal construction if studs can 70mm studs and 12.5mm plasterboard each side and taped.

 

Also if horizontal external cladding and using 25mm battens and chasing in electrical and plumbing elements and plaster skim you could reduce quite a bit.

 

If doing block walls 200mm (2x 4" blocks) plus cavity, plus 25mm vertical external battens, plus cladding and plastering. Even with 150mm cavity your down to 400mm.

[Crofter]

A bit out of the box thinking, could you use insulated box profile? You'd save the wall thickness conventionally taken up by battens and cladding.

[G and J]

I’ve not got the actual detail of the wall build up but from previous discussions with the architect but I believe even with our vertical larch cladding we are looking at getting within foot thick walls.  That may be with only the most basic level of insulation, and I will be looking at ways to improve the insulation without excessive cost or wall thickening.  
 

If I understand the term correctly then the insulated box profile is the stuff I’ll use for the roof of my man cave at the bottom of the garden, but for the house we’ve got our hearts set on untreated larch to go lovely and silver grey over time.  

[scottishjohn]

23 hours ago, G and J said:

Our architect said stick built as soon as he visited the site

I would not let your architect  decide it all 

he maybe has never used them 

the time you will take to make the frames -erect  and then pack stick build with insulation  cutting and wasting insulation will be a alot , and if not  very good fit -you will get air leaks 

with sips  insulation is already doane and air tightness is almost  certain

then all you need is vapor barrier held to wall with 25mm strips -which will be your service void for plumbing and electrics and then on with plasterboard

worst you will have is a box section to get toilet waste down to ground floor  in a corner somewhere ,probaly in the downsstairs toilet 

 

once slab is done and wall plate fixed down its a very simple job to fit sips on to them- 

 take a look at the process of fitting the joining splines between the panel dead easy

once ground floor panels are up fit a floor then next tow of panels --choices are vast 

-- but if you really want MVHR - then you will need a very thick floor structure to get the plumbing in.Idid not go for that for technical reasons of building inside an old granite house -floor thcikness wasl imted due to postion of upstairs windows --and nayway my wife insisted she wouls still be opening widows --so pointless and alot money saved -

If cooling insummer is an issue then get an ASHP that can also cool  as well as heat -then wall head plate and trusses -or if you want rooms in roof then you could use sips for the roof as well -they need no extra support,assuming it is not mega wide  -so you have attic completed in  one go 

just make sure you use double battons on top and a very good breathable membrane  -then on with your roof covering choice 

internet search will give you all the info you need

sit them on the wall fill in between -then next row of panels 

If you buy blank panels -you can even leave making window holes till they are all up .

 

 

I wonder why you do not get a price for burying the overhead cable , maybe would work out simpler /  cheaper in the long run ?

my quote for my elec supply -3phase 100kv from a pole 140yds away was 11k,with me digging the track   -so i can,t think it can be that expensive to drop a cable down each pole and run it underground across the entrance ,especailly if you dig the track for them 

a days digger hire will kill that . must be worth a enquiry 

If like here, they will supply the piping for the cable -you bury that with a draw cord   and its a simple job for them .

I,m suprised the cable is causing a problem as the minimum height is usally around 17ft -so most thing will go under that 

Edited May 28 by scottishjohn

[ProDave]

If you want best insulation for a given thickness, then do as we did, make all the elements of your wall, insulation (which brick and block does not)

 

So we have 200mm timber frame full fill with insulation and on the outside, 100mm thick wood fibre (more insulation) and rendered on the outside.

 

Inside a 25mm service void for cables and pipes then plasterboard and skim.

 

Total thickness 380mm.

[scottishjohn]

On 27/05/2024 at 08:47, G and J said:

but presumably there could be a reason why it’s not a common solution, perhaps because of the greater number of joints and the sheer volume of glue needed.  

less joints and asplines means cheaper and if crane is possible then thats why they go for large panels 

a telehanlder must go under your overhead cable --so you could stil use one to lift heavy things -ask sips panel suppiiers about wieghts of their panels 

iwould use my swing dumper with my lifting attachment and screw 4x2 to each panel and lift with that with a chain around the scaffolding pole on the dumper 

If you look through my posting you will see iwas lifting up to 500kgs with that no problem , so a sips panel would be no problem 

 

Edited May 28 by scottishjohn

[G and J]

2 hours ago, scottishjohn said:

I would not let your architect  decide it all 

he maybe has never used them

He has, many times, but I still want to make our own informed choices.  We did set out to find an architect would would work with us collaboratively, and we appear to have got very lucky.

[G and J]

2 hours ago, scottishjohn said:

once slab is done and wall plate fixed down its a very simple job to

Which to varying degrees appears to describe most systems.  There’s more work I need to do but it appears a very good plan is to build the downstairs walls (in that the details and costs vary as does the need for a second pair of hands, but there are all pretty similar) put on a ballon floor (likely using 304mm posi joists), repeat for second floor and get help popping the trusses up.

 

Roof space is too small to bother making it a warm loft 

[G and J]

3 hours ago, scottishjohn said:

I wonder why you do not get a price for burying the overhead cable

Our supply will be u/g, have gone through that with the network planner chap (incredibly helpful), but neighbours o/h supply crosses over where will be a single story part of the build.  Not measured it but I would guess lowest part is circa 15ft. They have no interest in converting to u/g and they would rather we didn’t develop next door so we just have to work round it.   Can’t have a temp supply either.  Ho humm.

[G and J]

3 hours ago, ProDave said:

If you want best insulation for a given thickness, then do as we did, make all the elements of your wall, insulation (which brick and block does not)

 

So we have 200mm timber frame full fill with insulation and on the outside, 100mm thick wood fibre (more insulation) and rendered on the outside.

 

Inside a 25mm service void for cables and pipes then plasterboard and skim.

 

Total thickness 380mm.

That sort of thing is the front runner/base case.  Current thinking is 140mm frame with 120mm insulation between to give service void.  In some places we will line with ply under the plasterboard to give flexibility in wall fixings and maybe slightly better sound attenuation.  We will need another insulation layer but I’m a bit confused about whether that goes inside or outside the frame and sheathing board.  Baton and counter baton the larch cladding so circa 255mm plus the extra layer of insulation.   But I’ve a lot more reading to do yet.  And no one has mentioned ICF yet lol

[scottishjohn]

22 minutes ago, G and J said:

And no one has mentioned ICF yet lol

If you cannot get in your site with a concrete truck and pump --then that is out

[scottishjohn]

23 minutes ago, G and J said:

Current thinking is 140mm frame with 120mm insulation between to give service void

not sure on english regs ,but scotland 140mm is minimum--so sips gives you that in one go 

[scottishjohn]

33 minutes ago, G and J said:

They have no interest in converting to u/g

 of curse they don,t

so move it for them and get rid of all your problems

[scottishjohn]

1 hour ago, G and J said:

Roof space is too small to bother making it a warm lof

you could go for vaulted ceiling upstairs though?

[Kelvin]

5 minutes ago, scottishjohn said:

you could go for vaulted ceiling upstairs though?

What we did in the upstairs sitting room. Transformed what would have been a small awkwardly shaped room. 

[JohnMo]

39 minutes ago, G and J said:

And no one has mentioned ICF yet lol

Because you want vertical cladding and have 300mm wall thickness. My ICF blocks started at 365mm thick before internal service void and external cladding.

 

 

[scottishjohn]

1 minute ago, Kelvin said:

What we did in the upstairs sitting room. Transformed what would have been a small awkwardly shaped room. 

maybe make it an uoside down house to get that extra head space in living areas?

[Kelvin]

1 minute ago, scottishjohn said:

maybe make it an uoside down house to get that extra head space in living areas?

We vaulted one half of the area upstairs and raised the ceiling height in our bedroom. It’s coombed too we left it all open on one side so the angled ceiling meets the outside wall rather than creating wasted pointless cupboard space we’d never use. Heb Homes standard upstairs layout wastes a lot of space and creates long narrow bedrooms which is  a common problem with room in roof designs.