I’ve had this Piko freight shed for a number of years. It started inside back in the 80s and got place outside when I started my layout in 2003.
Although it is small, the doors looked about 1:20, so I decided to keep the basic structure. But, I wanted something a bit larger. I don’t have a lot of depth on the siding, but it is fairly long. I replaced the roof with two 30 inch pieces of acrylic and covered these with some cedar shingles I had. That was the tedious part. The platform was built up from some double wall plastic I had and covered with redwood strips. The model was repainted with some exterior latex paint. The details were glued in place with silicone and it’s ready to go. It’s a bit too messy to put it out today, so you just get the “builder’s” photographs.