Ideas for "green"/sustainable extension

[Withington]

We are currently in a three bedroom 30s semi and getting a two storey extension built, adding two more bedrooms, making kitchen wider, adding downstairs loo etc. We want to take the opportunity to both retrofit our current house and make the new extension as green as possible. With likely energy/water/general utility insecurity likely over the coming decades as well, we want to design the house to be able to operate as much "off grid" as possible.

So I'm looking for ideas (and good suppliers - in Manchester/northwest) as to things we can do, and also types of things to use (e.g. is Cork insulation any good?) Things I've thought about so far -

• Green roof on at least part of the current kitchen extension
• rain and greywater recycling including sunken tank in garden
• Solar panels on roof, feeding into battery pack
• Retrofitting insulation under current flooring largely (suspended timber)
• Installing fast electric charger for car

We already have raised beds in the back garden so would be adding to those. The garden is West facing, and we have a small garden and driveway at the front facing East.

Anything else that anyone can think of? Any good suppliers or contractors for what I have listed? This is a long term home so "payback" on investment isn't so much of a big thing, albeit ideas can't be ludicrously expensive!

Hopeful bump!

Subbing for ideas as this is what we are planning as well!
We are also looking into the Tesla house capacitor/storage thingy to link up to the solar panels.
I'm also vaguely looking at heat pumps...

Interested! We are just in planning stages to renovate a 20s semi.
Our architect has suggested an acrylic render to insulate the house- maybe green in terms of reducing bills despite material not being green...

I mean reducing energy use as well as bills oops!

If you’re in Manchester have you been in touch with the Carbon co-op? They will do a home assessment and advise on retrofitting. They can also recommend suppliers/tradespeople.

The only other thing I can suggest is to consider incorporating a sunroom/lots of glass if the extension is south facing to capture solar heat.

No I haven't @fishlegs - thanks for that.

@cyberworrier - one of the things suggested to us for insulation was cork, as being potentially more environmentally friendly. Apparently it's a good sound insulator too?

I'd be interested to hear from anyone who actually has solar panels connected to batteries, it all sounds great in principle but may be one of those things that doesnt really work in practise.

Air or ground source heat pump. We went for air source as it was cheaper but ground source is more efficient.
We also had to install a ducting system to make the house more airtight and balance out the insulation differences between the old and the new parts.

We did think about heat pumps but it doesnt seem like the air source ones have too many benefits over a new/efficient gas boiler and out garden definitely isn't big enough for the ground source ones which I think are more efficient?

Yes, ground source is more efficient. For us it was the right choice, we have a fairly big house and the heating costs the same as a 3 bed with a combi (which wouldn't have worked for the amount of bathrooms either).
But it might not be feasible in your circumstances.
(I would have loved a system that uses bathwater for loo flushing but couldn't find a way to make that work.)