Here is a "house" that I built using cubes.
 Questions:
 What is the largest number of cubes that I could have used to make my house?

 What is the smallest number of cubes that I could have used to make my house?
Use this Java applet from the Freudenthal Institute to help you think about the possible arrangements:
Building houses with side views
http://www.fi.uu.nl/toepassingen/02015/toepassing_wisweb.en.html