im a joiner
there very well made . to start to build these u would need to be
skillful with wood,and a workshop ,or get someone to draw up plans with
sizes and a list of matials, if ur handy at all, i dont see why it cant be done.
realy depending on the wind it would be quite easy to get wet inside they would need to be in a sheltered area ?. :-/
price to get workshop to do this £150 try ur self do they have to be that elaberate.? :)