Grand designs: off site construction

[Post and beam]

I watched Kevin yesterday exploring the off site construction of a 'modular' single story house.

Am i missing something? all that appeared to happen is the house was built in sections in a warehouse, it took just as long as it would have done on site as far as i could tell. Other than, of course, not at the potential  mercy of the weather. Is this enough to warrant the process.

The customer was impressed that once the house was delivered it went together quickly. But it still took quite a while, just not within the customers visibility.

Only one house was able to be built at a time in the warehouse. Surely this is not a sustainable model from a financial point of view.

 

I imagine true off site modular houses would be a 'call off' from a parts warehouse of pre made  for example...

3 x 4 metre wall panels with window

2 x 2 metre panels with door.

n X 4 metre wall panels no window.  etc. You get the idea.

 

Much like a SIPS design might be now but scaled for volume. Any design of house you want but from the standard parts list.

Appreciate not everyone likes SIPS but i hope the description still holds.

 

I believe the actual assembly should still be on site.

 

[ProDave]

It is supposed to make the build more precise and more controlled.

 

But the price.  £800K for the build, not including the plot (another £650K)  Eye watering figures for me, both of them.  And I don't recall them saying how many square metres.  Also no details of insulation levels, heating system etc.

 

And in spite of it being built in a factory, it appears the plumbers got no thought in the design and they still had to work out pipe routes and drill all the holes just as they would in any other build.

[SteamyTea]

I had a tour around Frame's Redruth factory. The production manager told me about the great pains they go to ensure the quality and fit is right.

Then electricians and plumbers come along and drill holes wherever they feel like it, totally ignoring all instructions and drawings.

[ProDave]

2 hours ago, SteamyTea said:

Then electricians and plumbers come along and drill holes wherever they feel like it, totally ignoring all instructions and drawings.

I briefly did some work for a passive house building company here.  I was not allowed to drill a hole through the external wall of the building (i.e. through the air tight layer)  If I needed a hole, I had to discuss it, and one of the joiners would drill the hole in the agreed place (not always where I wanted it) and they would then seal the cable penetration afterwards.

[saveasteading]

4 hours ago, Post and beam said:

Am i missing something? all that appeared to happen is the house was built in sections in a warehouse

Perhaps. I went to a modular factory and was surprised to see it was just an old shed, with people slicing osb and cutting battens, and another nailing it on a bench. 

The difference though was quite simply in taking away all manual measuring. A computerised machine drew cutting lines and part numbers, straight from a schedule. So there was minimal waste, and much reduced skill level.

Also, they took in fresh timber, in wrapped 6m3 or 4.8m3  bundles,  straight from the docks and it never got wet so the quality was more certain.

[Spinny]

I suspect that someone like Elon Musk could be capable of changing house building. Would seem to require an awful lot of careful engineering work to define a modular construction system and automate the production of modules at scale. Compare a car production line or modern automated manufacturing plant to what you describe and there is a vast gulf. It would take a massive investment, and while Americans were willing to provide Musk, Bezos etc with huge unlimited funding and a licence to make losses for a decade or more to get electric cars, and Amazon, I doubt such a tech investment mania could ever be created for automating housebuilding. 

 

I think there are many ridiculous things about housebuilding including the complete absence of service void planning. If you see what goes on today in say aerospace engineering design, it makes domestic architectural design look like it is in the dark ages. The only thing which I guess comes close is in mass building where companies throw up steel frame and modular concrete panel multi-storey blocks of student accomodation or tiny flats for rent. It is a strange world where people knocked down 60's tower blocks that became slums, but now build modern equivalents that will also likely become slums down the line, and where houses built 100 years ago give people more space to live than they do today.

[saveasteading]

8 minutes ago, Spinny said:

Would seem to require an awful lot of careful engineering work to define a modular construction system and automate the production of modules at scale.

 

It has been happening for decades. I worked with steel buildings which were made to order and slotted together beautifully on site. They were not even modular, but to any dimensions but there were parameters.

Most of it was automatic manufacture, with humans just doing the odd tack weld to get it started.

 

It was also possible to make a frame on site and lift it into place  By chance I have a photo in front of me from some box sorting.

THe odd thing was that the steel erectors didn't want to know about this. partly habit, partly macho, but the time difference was very small.

 

The big difference is that you then took this hitech kit to a muddy site and worked at 8m in the air in all weathers.