Water Tight Shell

[steve77r]

As a rough guide what % of overall build costs is to be attributed to completing water tight shell? Assuming brick and block construction.

 

Thanks

 

 

[PeterW]

50% on something of the 130-150sqm 2 storey type build. 

 

Thats assuming nothing fancy, mid range windows and doors, tile roof and facing bricks at £700/Th.  Standard roof construction, trusses etc. 

[ultramods]

Very difficult to say as there are so many variables that can vary massively, such as:

The location that you are building - labour is based on supply and demand and therefore varies massively throughout the UK and Ireland.

Type of bricks

Level of insulation

Level of airtightness

Number of Levels, a 200 sqm 1 storey bungalow could practically have the same foundation and roofing costs compared to a 2 storey 400 sqm house.

The size of the house - a 200 sqm house could have the same number of kitchens and ensuites as a 400 sqm house.

The design of the house - large open plan areas might need more steel compared to a more conventional layout.

foundations/groundworks - for example a sloping site can add a lot of cost.

Glazing - are you having lots of glazing, sliding doors, structural glazing

Roofing material - concrete tiles are a lot cheaper compared to natural slate or Zinc

Number of bathrooms/ensuites

Interior finishes such as Kitchens, stair, sanitary ware and flooring

Service connections, - if the services are not on the plot boundary connections can be expensive.

 

Have a look at these cost calculators

https://www.homebuilding.co.uk/calculator/

 

The Fleming Homes calculator is for Timber Frame

https://www.fleminghomes.co.uk/self-build-resources/cost-calculator/

 

 

[scottishjohn]

How long is a piece of string?

what type of blocks/bricks ? what size windows +doors +what quality? 

same goes for roof what type what span what type of exterior roof cladding 

tiles ,corrugated tin ,standing seam steel or zinc -

who is doing it you or builders?

how much you going to spend to get out of the ground + services  should be your first thought 

this is why people use an average cost per sqm  floor area  as a starting point

and it all starts with your plan so you can cost it 

alot more people qualified to give a batter answer than me 

but just think you can spend 4k on a kitchen or 50k 

so plan first -and stick to  it 

changing your mind later will cost you  a lot of money

 

 

 

Edited May 3, 2019 by scottishjohn

[steve77r]

14 minutes ago, scottishjohn said:

How long is a piece of string?

what type of blocks/bricks ? what size windows +doors +what quality? 

same goes for roof what type what span what type of exterior roof cladding 

tiles ,corrugated tin ,standing seam steel or zinc -

who is doing it you or builders?

how much you going to spend to get out of the ground + services  should be your first thought 

this is why people use an average cost per sqm  floor area  as a starting point

and it all starts with your plan so you can cost it 

 

 

Yes of cause many variables but ballparks still exist, 10% 30% 50% 80%. wasn't asking for exact figure just rough idea.

[Ian]

Mine was a small 2 bed 71 sq.m timber frame bungalow on a steeply sloping rural site in Wales with difficult access. Building Regs min compliant with average 0.15 'U' values and 3G windows

Getting to a stage of watertight shell c/w insulation, roof and wall cladding and windows and all internal walls (but no internal doors) was 50% of total build budget.

[nod]

2 hours ago, steve77r said:

As a rough guide what % of overall build costs is to be attributed to completing water tight shell? Assuming brick and block construction.

 

Thanks

 

 

Ours is two story BB 

285 mtrs Slate roof Around £75000 Windows on top of that 

[Thedreamer]

All the stuff above.

 

Remember if you project managing or doing the work yourself you can add 20% VAT for materials. Your get this back at the end but cash can be king in getting to wind and watertight. if borrowing your lender will expect you to finance VAT as well as a contingency.

 

A builder will be zero rating invoices, but will add a margin.

 

Do get a more reliable estimate I would break it up to: land & services/access ,foundations and then wind and watertight. Assuming nothing fancy or unusual you could get a reasonable idea from that.

[Conor]

3 hours ago, steve77r said:

As a rough guide what % of overall build costs is to be attributed to completing water tight shell? Assuming brick and block construction.

 

Thanks

 

 

 

For ICF construction, I've been quoted £400m2 for a "thermal envelope". That's passive slab, intermediate floors and supporting walls, ICF structure and EPS roof panel system. Adding in windows, render and roofing, I expect this to come up to about £600m/2.

[nod]

19 minutes ago, Conor said:

 

For ICF construction, I've been quoted £400m2 for a "thermal envelope". That's passive slab, intermediate floors and supporting walls, ICF structure and EPS roof panel system. Adding in windows, render and roofing, I expect this to come up to about £600m/2.

600 /2 I would take there hand off 

incredible price 

[Conor]

@nod Northern Ireland... Materials and labour a dose bit cheaper here. But that's a rough price and probably misses a lot... But I'm aiming for sub £1k/m passive House build.

[puntloos]

Just an errant thought, but would a watertight shell also keep ants out? If the house is properly watertight, it by definition (?) would, but perhaps not?

[scottishjohn]

18 hours ago, puntloos said:

Just an errant thought, but would a watertight shell also keep ants out? If the house is properly watertight, it by definition (?) would, but perhaps not?

ants like dry places to build nests --but if its built right should be nowhere for them to get in 

If its not airtight its not ant proof 

Edited May 5, 2019 by scottishjohn