I form groups of students and give each group a very large wall covered
with sheets of paper(roll). Each group creates a "window" on the world.
We determine the VP based on where you would most likely stand to view
the "room" and horizon based on the height of the average student. Thgen
using a tack on the VP and a piece of chalked string we use the existing
points in the room to project the boundaries of the new room. The "room
" becomes an extension of my art room. A few years ago we went out into
the school and added new rooms at the end of all the hall ways. The kids
love doing this . Many of them have designed "additions " to their
bedrooms at home using this technique.