This video tutorial is in the Computers & Programming category which will show you how to build a simple house in SketchUp. Start with the floor plan, draw a rectangular main living space and attach a small extra room. Next you use the push pull tool and pull the house up to as high as you want. You can make it 21 feet. Now draw the roof line in the center of the house along the length and draw the lines for sloping part of the roof on either side. Now grab the center of the roof and lift it up to the desired height. Watch the video for more tips.