Hello to everyone at this amazing forum!
I just signed up to hopefully take part in the exciting discussions regarding green builds.
I have studied architecture and I'm very interested in the era of the 1950-60's modernist buildings and would like to build my own home one day featuring some of the typical design features of this period.
While studying architecture very little focus were on the actual construction so I know almost nothing about the subject! So I hope I can get a little help here!
I have started sketching a house with a flat roof and slender fascia (~300mm total thickness)with a large 100cm overhang. I have tried to find information on how to actually construct something like the attached photos without too much thermal bridging happening. (it seems like i can only attach one photo per post?)
With my limited knowledge I see the challenge with this construction method that the joists need to puncture the thermal envelope to form the large overhang. I have tried to find a way to improve this and have worked on a way to make it seem like the joists continue from the side to the outside, but they're actually cut to stop the thermal bridge. I hope my drawings make some sense as English isn't my first language and writing technical build lingo isn't my biggest skill.

I know the glazing will be bad in regards to heat transmission but I have found some triple glazed units (36 mm with krypton filling: 0.5 W/m2K) and they seem to be improved all the time so maybe a fairly good thermal envelope could be created sometime in the near future.
Trying to find a solution to this thermal envelope problem got me thinking if it's even worth the effort to eliminate the thermal bridge in the joists when the heat transmission is so much higher in the glazing it self :/

I would love your comments on a minimal construction like this. I haven't decided if I would like to be able to see the construction joists as in one of the referenced photos or if I prefer the minimal continuous surface, but I guess the underlying construction will be the same/similar?

I know the part of the build is just one of many many design challenges, but I need to start somewhere.
Thank you for reading! :)

Check out this green retrofit of a 1960s timber-frame house http://lewesecoopenhouses.org.uk/info/lewes-eco-open-houses/60-barons-down

We were there on Saturday.

You might be able to use similar techniques - though of course you could do even better in a new build. Ask Ian Mackay, I'm sure he would be interested in your project.

I don't know how well it would sit with minimalist profiles,- windows, supports, structural members, etc not as good as metal admittedly, but engineered wood throughout with it's better thermal properties would obviously minimise thermal breaks at junctions

owlman: Yes I haven't decided on the materials yet because I don't have the knowledge yet, but I was thinking that with a construction as the attached with visible joists, I do prefer a gluelam structure due to the warmth of the wood. And I also thought that it would make the thermal problems smaller.

Ed: I guess it depends on how you look at that style of architecture. I think it's correct that they didn't think about energy consumption like we do today, but I think a more dominant reason for the design change that happened back then had do do with the relationship between inside and outside and the new possibilities to melt these together with the large glazing that appeared. This is also the main focal point in my design. I think it is interesting to figure out how green such a design can be made to be :)

owlman: I agree that it could be beautiful, but the weight of such a green roof would be enormous. The main roof of the build is 150m2 so I guess it would cause other structural challenges.

I've no idea if its EPC / SAP performance is up to GBF standards but is this the sort of thing you had in mind?

http://www.dualchas.com/galtrigall.html

Some of the other designs by that architect have a lot of glass too, but I picked that one because of the flat roof.

IIRC at least some have shutters built into the designs?

As buidings get larger (more volume), the external surface to floor space ratio decreases, which is why office blocks often get away with glass facades. For house-size buildings, it's not possible to do much better than scrape through the weak building regs, with lots of glass. Very small houses are forced into really small window areas.

However, for ultra slim profile metal windows with half-decent Uw, see Vitrocsa, tho their UK agent's website is chaotic.

How about - deep 2-skin beam with separating 'noggins' (cross-pieces) at ceiling height, allowing insulation between, with further 'ladder section' coach-screwed on to form the overhang with reduced thermal bridging.

Hi and welcome! This sounds like a fantastic project as it's my favourite architectural era! Sadly I don't think the UK took to it nearly as much as 'newer' countries like the USA, Australia, South Africa etc.

If I had the money I'd build a house inspired by the 1950s atomic age of space, the Sputnik and atomic models. It could probably be made fairly green with modern insulation, aligning the main area of glazing correctly, solar PV/thermal on the roof(though of course solar PV wasn't used domestically in those days, I think the panels would suit the style and spirit).

Ed

Posted By: atomicbisfThis sounds like a fantastic project as it's my favourite architectural era! Sadly I don't think the UK took to it nearly as much as 'newer' countries like the USA, Australia, South Africa etc.

Maybe latitude is of some relevance? Alaska aside, the USA is essentially below latitude 49N The most southerly point on the GB Mainland is Lizard Point, Cornwall at 49°57′N.

Was there in June about 3 years ago and it WAS sunny. (Yes we were lucky.) The near-vertical sunlight seemed quite Mediterranean.