I think DH is a builder so good op for him!
I use old 1x6 planks that come from the horses paddock fencing, I screw two short pieces onto the ends of a longer section to make an 'H' with the narrow 1" side upwards. It's particularly nice for the Silkie babies as the 6" is easy for them to hop up onto.
As for Bridgie's dilemma, I would see about one of those small animal crates, or a pre-fab dog house.
@micstrachan not sure about your weather there, or if the area is covered. But if covered than a simple cardboard box would be a cozy area to reside in, my hens' favourite areas to roost at times have been various cardboard boxes that I have placed around the barn for them to hide in or warm up in when moulting. Currently have Holly being a silly broody in one.
The box can be thrown out when not needed, or in need of replacing.