Here is a set of plans for making a Duplex apartment building, which could be part of a larger apartment complex. They built a lot of these in the 60's and 70's, for low income housing. You won't find a kit available, and this is my own design based on local prototypes. Footprint is 1 1/2 x 3 and is an easy build. It features a mansard roof, and unique slider type windows and sliding glass doors, which were easily modified from Rich's window and door sheets (see sketches). Two versions are shown, one with clapboard siding, and one with brick.
Choice of materials is up to you. It can be done in wood but sketches are based on styrene thicknesses. If you use another material adjust dimensions accordingly. Paint parts before assembly, except where the edges glue to other parts.
The building directions and materials are in the sketches, and to make your build easier you can enlarge them to full size and print them out. Read directions in assembly sketches before cutting out parts as you may want to change some sizes or cut fewer, or additional, openings.
Included sketches are: Overview sketches, Parts templates, Assembly sketches, and PDF's.
To print the part templates actual size, use the PDF's. Select best printer quality, set PDF zoom to 100%, and page scaling to "none" or actual size. Check your printed page to see that 3" lines are exactly 3" long. Once you have template printed, you can cut with scissors (leave a 1/8" border) and arrange on your material for maximum sheet usage. Part templates for siding are a mirror image, when needed, so that you can cut walls with siding side down (easier to cut). Be sure siding grooves are oriented correctly. Use rubber cement or Krylon Easy Tack Repositionable Adhesive to glue paper templates to your material and then just cut on lines. No measuring ! Paper comes off easily.
Cut out parts carefully using a SERB and straight edge. The best way to cut out window openings is with a corner punch. It is important to follow assembly sketches IN SEQUENCE or some parts may not fit.
NOTE: In my newest sketch sets, I changed from architectural feet and inches to decimals. When you are dealing with materials that are as thin as 15 thousandths of an inch thick, tolerances become very important. With the decimals I am able to get to the nearest 10 thousanths of an inch, which makes things much more precise on the templates. You'll never notice these changes, because the templates are not dimensioned, but the precision is there.
PDF links:
https://www.dropbox.com/s/r2wagp7q6mywixj/sdabpt1pdf.pdfhttps://www.dropbox.com/s/r633yrhy87kuqvt/sdabpt2pdf.pdfhttps://www.dropbox.com/s/huk54i7expdpvzk/sdabpt3pdf.pdfhttps://www.dropbox.com/s/pvi09kfg3mt64dz/sdabpt4pdf.pdf