Hansa Systems:This is an interesting idea.Remember when you were young and played with "LEGO" blocks/ Well this is based on a similar concept. Hansa Systems consists if injected plastic elements including building blocks of various sizes.Also available are roofing materials,beam sections,individual roof tiles(two types),also plastic.
The big advantage is the possibilities of building large,light weight structures,that just won't be possible in plaster. If you build dioramas,write for their catalog!!.Besides,the price is exceptionally reasonable. They can be used on plaster buildings as well.
Good modelers seal of approval!!
— James Welch, Modeler Reviewer, MILCIV Mag.