My 1950s system had the main thermostat next to a coal effect gas fire in the living room. When I had the chance to renew I put it on the landing instead, replaced older radiators for newer (cosmetic/corrosion/seized vales), but it was too costly and disruptive to replace the single (half inch) pipe arrangement.  In a new build extension, I went for wet underfloor with a manifold, dedicated pump and 3 zone thermostats, designed and installed by my local Plumber.  

 

With a condensing boiler instead of the old Potterton Diplomat (introduced in 1955), gas use has reduced by around 25%, but I have also had more breakdowns in 3 years, than in 20+ years that I used the old system. The only previous problem was the pilot light occasionally blowing out with a strong wind in the wrong direction. I kept a spare universal thermocouple but never needed it. Luckily a new boiler motor fan failure was repaired under warranty and I was able to replace failed “Honeywell type” valve motors. I even had to replace one head due to a rack & pinion problem. This DIY probably saved hundreds on plumber’s charges.

 

Taking into account the capital cost, reliability and likely maintenance the payback period may be longer than the service life of the boiler, in effect probably not paying back in my lifetime. In operation my carbon footprint is lower, but there is also the embodied energy to consider.

 

As I said in an earlier comment, unless something like this is scaled up hugely, there just isn’t a financial or other justification for significant input from a professional (IEng/CEng type) engineer. There is another thread about consumer units. In my situation, I realised that I needed an accredited Gas Safe Plumber and Part P Electrician. I found that despite an enthusiasm to get involved, it was more sensible to just let them get on with it, once trust was established.

 

Ways to “scale up” include standardisation, such a modular systems and prefabrication.  An example that comes to mind (I was Training Manager for the M&E contractor) was the QE hospital  https://www.designbuild-network.com/projects/birmingham/.  This is likely to represent something close to "the state of the art" with Consulting Engineers collaborating with the M&E Contractor's Modular Systems factory, value engineering and life cycle cost being key issues. Perhaps a useful starting point for research?    

My 1950s system had the main thermostat next to a coal effect gas fire in the living room. When I had the chance to renew I put it on the landing instead, replaced older radiators for newer (cosmetic/corrosion/seized vales), but it was too costly and disruptive to replace the single (half inch) pipe arrangement.  In a new build extension, I went for wet underfloor with a manifold, dedicated pump and 3 zone thermostats, designed and installed by my local Plumber.  

 

With a condensing boiler instead of the old Potterton Diplomat (introduced in 1955), gas use has reduced by around 25%, but I have also had more breakdowns in 3 years, than in 20+ years that I used the old system. The only previous problem was the pilot light occasionally blowing out with a strong wind in the wrong direction. I kept a spare universal thermocouple but never needed it. Luckily a new boiler motor fan failure was repaired under warranty and I was able to replace failed “Honeywell type” valve motors. I even had to replace one head due to a rack & pinion problem. This DIY probably saved hundreds on plumber’s charges.

 

Taking into account the capital cost, reliability and likely maintenance the payback period may be longer than the service life of the boiler, in effect probably not paying back in my lifetime. In operation my carbon footprint is lower, but there is also the embodied energy to consider.

 

As I said in an earlier comment, unless something like this is scaled up hugely, there just isn’t a financial or other justification for significant input from a professional (IEng/CEng type) engineer. There is another thread about consumer units. In my situation, I realised that I needed an accredited Gas Safe Plumber and Part P Electrician. I found that despite an enthusiasm to get involved, it was more sensible to just let them get on with it, once trust was established.

 

Ways to “scale up” include standardisation, such a modular systems and prefabrication.  An example that comes to mind (I was Training Manager for the M&E contractor) was the QE hospital  https://www.designbuild-network.com/projects/birmingham/.  This is likely to represent something close to "the state of the art" with Consulting Engineers collaborating with the M&E Contractor's Modular Systems factory, value engineering and life cycle cost being key issues. Perhaps a useful starting point for research?