Measure the area of your home where you want to add a sun room. Draw a plan of this area with all your measurements marked clearly. Be sure to include precise lengths, heights and distances.
Decide where you will be placing the windows in the sun room and what types of windows you will be using. You could select side-sliding windows, up and down windows or roll-out windows. Also, select the type of glass. Insulated glass windows will retain the most heat on chilly mornings.Vinyl window panes are not good for heated or cooled rooms.
Make a list of materials and supplies you will need to build the frame of the room and install the windows. Purchase the supplies or have them shipped to your home.
Install a concrete foundation for the floor if necessary. Building the framing, leaving room for electrical configurations, plumbing needs, heat and air conditioning. Since you will have many windows, make sure you install the appropriately sized headers; the boards that go horizontally over the windows.
Build the front and side walls, leaving openings for the doors and the windows. Install the many windows, and then the door. Insulate the walls on the inside and add siding to the exterior of the room.
Finish the interior by adding wall fixtures and outlets, and design and decorate the inside of your sun room.