David Coles

Hi Cath,  we have a straw bale Science centre at my school with curved walls. The plumbers just notched out the back about every yard or so and added silicone sealant, hasn't leaked. You have a tighter curve so you'd need more notches.
Regards Dave.

Underfloor heating is indeed the main aim. I will be running the pipework myself. I too have been quoted over 20k for a boiler ( so far ) but there are now cheaper options. I'm interested to find out what others have used and had either success or failure with.

I'm in the process of getting ready to build an off grid house. All the usual gear, solar panels, wind turbine, evacuation tubes for hot water and preheat of heating system water. I'm interested in wood boilers that people have used or know about here in Australia. I'm not going down the rocket path or pellet fuel so it will be either a wood boiler or a gasification wood boiler that will be in a dedicated heating room so it doesn't need to look pretty and there is no need for a window. I'd appreciate it if experience good or bad could be shared. many thanks, Dave