steel frame house

recipio

Folks,
I'm thinking of building a courtyard house with lots of floor to ceiling glass.
As layman it would seem that steel frame construction would suit.
Are there any specialists in Ireland or is the whole idea just a money pit ?

JimmyMW

recipio wrote: »

Folks,
I'm thinking of building a courtyard house with lots of floor to ceiling glass.
As layman it would seem that steel frame construction would suit.
Are there any specialists in Ireland or is the whole idea just a money pit ?

Hi, Just something to look out for, as your % of glass increases as a ratio of the floor area the value the glass has to achieve significantly increases to comply with building regs part L, BER etc. If your having a lot of glazing your glazing could end up costing you a fortune, quadruple glazing etc, imo get an energy consultant on board asap before you finalize design.

recipio

JimmyMW wrote: »

Hi, Just something to look out for, as your % of glass increases as a ratio of the floor area the value the glass has to achieve significantly increases to comply with building regs part L, BER etc. If your having a lot of glazing your glazing could end up costing you a fortune, quadruple glazing etc, imo get an energy consultant on board asap before you finalize design.

Thanks.
I'm just trying to get a basic design together before approaching an architect.
Its a clean look and I don't mind it being a bit industrial. I'd prefer to use an experienced fabricator as the local builders will not have much experience of this. An Energy Consultant is a great idea.
Trouble seems to be that its not much used in residential construction - any advice appreciated.

JimmyMW

recipio wrote: »

Thanks.
I'm just trying to get a basic design together before approaching an architect.
Its a clean look and I don't mind it being a bit industrial. I'd prefer to use an experienced fabricator as the local builders will not have much experience of this. An Energy Consultant is a great idea.
Trouble seems to be that its not much used in residential construction - any advice appreciated.

No offense, but imo you may be putting the cart before the horse, once you have a total budget sorted out approaching an architect is the first port of call, getting a steel frame is very easy I work with them all the time.

I have a feeling what you are looking for is very sleek and minimalist look, that cost significantly more than a standard build. Do you mind me asking what size house are you after and what is the budget?

Just note that you will pay significantly more for the engineer to design the steel frame that standard house construction.

recipio

JimmyMW wrote: »

No offense, but imo you may be putting the cart before the horse, once you have a total budget sorted out approaching an architect is the first port of call, getting a steel frame is very easy I work with them all the time.

I have a feeling what you are looking for is very sleek and minimalist look, that cost significantly more than a standard build. Do you mind me asking what size house are you after and what is the budget?

Just note that you will pay significantly more for the engineer to design the steel frame that standard house construction.

Thanks.
Yes, I'm thinking of a minimalist look with the bedroom block separated from the living and both looking into a courtyard . I have a half a hectare site which is dead flat.
I wouldn't use steel construction unless it offered a significantly cheaper building cost than block build. You seem to be saying there is no advantage ?

JimmyMW

recipio wrote: »

Thanks.
Yes, I'm thinking of a minimalist look with the bedroom block separated from the living and both looking into a courtyard . I have a half a hectare site which is dead flat.
I wouldn't use steel construction unless it offered a significantly cheaper building cost than block build. You seem to be saying there is no advantage ?

You would need to speak with a QS on that as I have not done a costing exercise on that type of thing before, however it stands to reason that there is more engineering on a build like that and therefore this will carry a higher engineering cost, steel is not cheap either, but again a QS will guide you on this. I can definitely tell you the type of look you want to achieve is expensive.
The best advice I could give you is to define the budget first and design based on that.

Calahonda52

This is a megabucks project to get it to work right and eliminate thermal bridging etc with the steel work so best consider the glazing in terms of a curtain wall outside the framework as opposed to fitting anything in between which is the normal Joe Builder solution.
Google "glazed curtain wall" in advanced search.
Having said that the benefit of going with an industrial product is that it will work as its supposed to as opposed to Joe Builder eile horsing around with Provincial Glazing (Ulster,Leinster, Connacht...) units, a crate of wide gap fill foam, a roll of gaffer tape and a tube of Tec 7!

I really hope you get it to work.

BryanF

recipio wrote: »

Folks,
I'm thinking of building a courtyard house with lots of floor to ceiling glass.
As layman it would seem that steel frame construction would suit.
Are there any specialists in Ireland or is the whole idea just a money pit ?

What about this http://architectureireland.ie/wp-content/uploads/2015/01/D_Stevens-Mimetic-House.jpg

BryanF

recipio wrote: »

I wouldn't use steel construction unless it offered a significantly cheaper building cost than block build. You seem to be saying there is no advantage ?

So you want a bespoke glazed facade system that most builders won't be able to work with and you want it to be cheaper than a standard block build...

Drift

I'm working on a house that's almost identical to what you've described at the moment - and it's going to be more expensive than a traditional build of the same floor area. It's being constructed in a combination of masonry and a structural steel frame.

Once the openings in the wall get above a certain size masonry cannot be used. If you look at Technical Guidance Document A you can get an idea of the amount of openings you'll get away with in a standard masonry wall.

"Traditional" masonry construction with a triangulated timber roof structure has evolved as the most common form of construction in Ireland* partially because it is a reasonably cheap form of construction. It's also the form of construction that your average "local" builder will be most familiar with. Once you get into something different your material costs, design costs and construction costs will all increase but there are many who would argue the finished product is worth the increase.


* I count timber frame under this general heading. There may be some scope for an engineered timber structure to give you the openings you describe.

recipio

Thanks all for the generally encouraging advice.
I started thinking of steel frame as I presume large glazing units need a rigid frame. I envision a single story structure only, perhaps with a metal roof. I see all kinds of light steel companies online but none who offer a bespoke design. As a layman I find it hard to understand why stepping outside of your 'bog standard' design seems to send prices soaring.
This isn't my first house so I'd prefer to get my vision together first rather than ask an architect for his vision.
That's where I'm at and to Drift, I'd love to see a few photos of your finished house.

Drift

It's actually a client's house recipio so I wouldn't feel comfortable giving out too much information. An any rate it hasn't started on the ground yet - I'm designing the steel frame at the moment.

With regards to steel frame design you will need a structural engineer to do it. Some of the bigger steel fabricators offer a service of design and install but I have never seen that happen for a domestic house - and at any rate you should have your own engineer assessing any designs provided by the supplier to give an independant overview. It's a terrible analogy but you wouldn't take a drug company's advice on what medicines to use - you'd have your own doctor/pharmacist give you independant advice!

Prices for steel frames alone are not particularly high - some of the great QS contributors here will give you proper figures but I think fabricated and erected is sub €1000 per tonne. The problems arise when the shape of the house comes into it. If you want a steel frame in a portal shape it's simple to design, fabricate and erect. Once you start including fancy architectural features (including large glazed sections) the design, fabrication and installation gets very complicated, very fast! Add to that the excruciating level of detailed design required at every joint and junction to ensure thermal, air-tightness and weatherproof envelopes are continuous. The "standard" construction has a "standard" set of details so less design work involved.

recipio

Drift wrote: »

It's actually a client's house recipio so I wouldn't feel comfortable giving out too much information. An any rate it hasn't started on the ground yet - I'm designing the steel frame at the moment.

With regards to steel frame design you will need a structural engineer to do it. Some of the bigger steel fabricators offer a service of design and install but I have never seen that happen for a domestic house - and at any rate you should have your own engineer assessing any designs provided by the supplier to give an independant overview. It's a terrible analogy but you wouldn't take a drug company's advice on what medicines to use - you'd have your own doctor/pharmacist give you independant advice!

Prices for steel frames alone are not particularly high - some of the great QS contributors here will give you proper figures but I think fabricated and erected is sub €1000 per tonne. The problems arise when the shape of the house comes into it. If you want a steel frame in a portal shape it's simple to design, fabricate and erect. Once you start including fancy architectural features (including large glazed sections) the design, fabrication and installation gets very complicated, very fast! Add to that the excruciating level of detailed design required at every joint and junction to ensure thermal, air-tightness and weatherproof envelopes are continuous. The "standard" construction has a "standard" set of details so less design work involved.

Thanks Drift, that's very helpful.
I suppose what I was asking was is there any kind of semi- industrial method that would trade the finished look for the traditional build. I'm a great fan of the 'Hi-Tech' look - like the Pompidou centre.
It seems there is no 'off the shelf' building method that would also provide a bespoke design. I am prepared to stick to a very simple design - I presume that is what you call a 'portal' shape ?
I will certainly approach an architect for an initial consultation but thought I might ask on here first !

Calahonda52

In portal frame design, one of the main issues is catering for gable end wind load longitudinally along the building and this is usually done by either using cross bracing or block walls in-between the frames.

These may impact on your visual design so sometimes a standalone wall is built at the end that is designed to take the wind load, so maybe your north wall would be such. Just an idea

air

An alternative approach to this would be to use a standard portal frame roof structure and then site your building inside this with the columns outside the building's perimeter.
This gives you the option of using an off the shelf portal frame structure that would be common in agricultural and commercial buildings and wouldn't need any great structural design input, as it would be built to standard spans and bay spacings.
The design of the building that sits underneath the roof then becomes vastly easier from a structural perspective as you eliminate the live and dead loads of the roof from the equation.
Furthermore, it becomes really easy to continue the insulation up the wall and over the roof (which can be flat beneath the portal frame) as there is no structural wall to roof connection necessary.
It lends itself to a lightweight construction method such as timber frame which would make it easier to use an insulated foundation system.
The combination of eliminating the wall to roof junction and the use of an insulated foundation system should allow scope for increased glazing area while still coming within the thermal requirements of the building regs.

This is an award winning budget building design that uses a portal frame structure for some of the reasons i've mentioned, albeit it doesn't separate the portal frame from the primary building fabric as I'm advocating.
http://www.nacsba.org.uk/images/shoestring/18_shoestring13_ed-green.pdf

recipio

Thanks Air.
that's getting close to my search for factory fabricated steel construction.I'll research Barnhous and get back on here later.

Calahonda52

Most interesting link, air, thank you!
It looks like the curtain walls with no opes take the wind load as there is no bracing shown in the sketches.

air

Yes, if I was doing it myself I think a curtain wall could be fixed at ground level and to the underside of the portal frame. It may also need intermediate ties through to the building structure, a structural engineer would need to advise. These would create thermal bridges of course but the effect should be pretty minimal in the grand scheme of things.
I think it has a lot of potential to create a really energy efficient building that is cheap and fast to build.
In terms of aesthetics, it would be possible to fix a parapet around the perimeter of the portal frame at gutter level if one wished This would give the appearance of a flat roof, again similar to commercial units where a parapet hides shallow pitched roofs sections behind.
The difference would be that it would be overhanging the building perimeter though - not a bad thing if you have large glazed sections that will need summer shading.
The longitudinal wind loading on the portal frame could be reduced if you chose not to connect to the underside of the portal frame at the ends. This would mean only the cross section of the gables of the beams would need to be considered (or the rectangle enclosing the triangle it if you go with the flat roof look).

Drift

Just a note to point out that the structural and particularly durability requirements for domestic buildings are higher than for agricultural so be aware that you will almost certainly need larger steel for the same span.

Don't stand in your farm shed and assume you'll get the same size for the same cost if the building will be inhabited.

air

I think that's a given Drift, structural design input will most certainly be required as with any build but it should be very simple for the SE & thus relatively inexpensive. The real benefit is that the trusses / columns are commodity items and super simple to analyse.