Hi everyone. Thanks for all the feedback. We have had the discussion about making the snug double height, it would make a lovely ensuite, then we could make the family bathroom bigger or even squeeze in a box room. However, part of the brief was to have a vaulted living space, my wife particularly is a big fan of this!
I appreciate that everyone has opinions, but it's nice too hear from people who have actually been there and done it. It's hard to get an idea of what works just from some drawings!
With regards to a plant room, I was hoping there would be enough space in the utility. Im thinking wall mounted mvhr, air source heat pump on gable wall with associated hot water tank and what not just inside. Battery and electrical will hopefully be in the existing garage. Does that sound feasible, or is it wiser to have a separate plant and utility room?