You can create the base of the door by getting the grey (4 X 10) Lego, and then place the 2 Blue (2 X 4) Lego's above each other.
Step 2: Placing the window.
There is a cubic shaped red Lego with a built in yellow window in it. Place that above the Blue base. Now we have a WINDOW.
Step 3: Placing the door
Obtain the blue cubic (2 X 4) door shaped Lego and place it right next to the blue Lego above the grey base. Now you do have a door and window at the same height. Also obtain a single (2 X 2) blue Lego and put it right next to the door, just to complete the base design.
Step 4: Placing the Roof
Obtain 1 yellow (2 X 8) Lego and 2 yellow (2 X 4). Place them above the Window and the door, where each Lego should be placed on a half.
Step 5: Extra Roof Design
For some extra design to the roof, Obtain 1 red (2 X 8) Lego and 2 blue (2 X 2) and place the Red Lego exactly in the middle of the yellow roof, 1 step away from front and 1 step away from the back. Then Place the blue Lego's apart, each one of them should be 1 step away from the side.
Finally, You have a good designed and awesome front door with a window next to it.