Hi. I personally would go for wood. We,ve kept poultry of all types for several years our most trouble free housings are large above head height sheds. Like double storey play sheds, or you can buy those big hen sheds six foot square, with a pitched roof and the door in the middle with pop holes either side . The important things are the height and the ventilated eaves. These are well above roost height so the hens don't get a cold draft, but also they don't live in a fugg on warm summer nights. The plus with this design seems to be No Mites! We've had them four years now and so far nothing. Maybe it helps that you are in and out of the door each day I don't know? but so far so good.
As regards the playhouse I use, it is 6'x8' and about 8' high, so quite big. I keep a mix of broilers and bronze turkeys in this every year, about fifteen of each . It has five windows on two levels and I removed the upper platform inside and put perches for the turkeys to use when they get older and the broilers are cleared. Again no mites and a room with a view for the birds on both levels . Most so called chicken houses look pretty but are far too small. Birds need some space to get in under cover when it's lashing down or cold and windy.
Another excellent option is a dog run shed. You can drop a carpet roll down across the mesh window bit at night or during storms. Another cosy roomy option for your birds and again you can get in it. even sit with your birds! Don't fall for the ads and buy a minature house affair you will be burning it in a years time just to get rid of the mites we've been there many times .
Good luck regards Phil.