its a basic box.. if materiel is fairly strong.. just glue or make thin frame from wood.
think of a dog house... many plans for them... just adjust for size.
flat roof or peak... also hinge roof and front door..
I made one for Home generator.. hinged front and roof.. for running generator..
I used angled roof... for better rain-off.
I attached roof to front with hinge... and both lift up and hook up forming a A shaped roof when open.
because I did not care about weight... I used plywood.. and vinyl siding for looks. an real roof shingles for roof.