external thermal blocks rendering painting

Hi Everyone we recently removed the conservatory and foundout the walls were made of thermalite, we were told by a builder this is wrong and the fix would be expensive. I'm getting all kinds of quotes and opinions about this so really at a loss here as to what to do, I'm thinking the DIY way...

Hello experts the final leg of our house renovation is building a 5m x 2.5m detached utility room, using thermal blocks (internal & external with cavity insulation inside). As the utility/yoga room will stick out like a sore thumb we are looking to make it blend into the garden environment...