How to Add a Second Story Addition to a House Foundation

Get a local building inspector, contractor and architect to analyze the home's existing foundation. Before you add a second story to a home, you have to make sure the outer walls of the house are able to support the extra weight of a second story. Professionals will check for rotten wood and faults in the concrete. Once you get their approval, you can continue with the project.

Determine how many rooms you want on the second floor. Before actual construction begins, you need to figure out how many rooms and bedrooms will be on this additional floor. A professional contractor and architect can help you map out the dimensions of each room. This helps you determine where you need plumbing, electrical wiring and central air and heating. You may need to update these systems, especially if the home is older. You also have to figure out where to put the staircase and the kind of roof you want.

Reinforce the walls and foundation. If the outer walls and foundation cannot sustain the extra weight of a second story, you need to reinforce the outer walls with additional 2-by-4 studs. You may need to call the building inspector again to make sure the additional fortifications are up to code.

Remove the existing roof from the house. You need a crane to take the roof off and add ceiling and floor joints. If you can't remove the roof yourself, you may need a professional contractor to demolish the roof without harming the other structures in the home. Mark the area where you want to place the stairs. Without a roof, your family may have to relocate or you can opt for a weatherproof cover.

Add ceiling and floor joists. The ceiling and floor joists should be at least 2 inches thick by 12 inches wide. You may need to use wood I-beams, depending on the plans and local building codes. Ceiling and floor joists should be 16 inches or 24 inches apart for support. Once joists are added, put down plywood tongue and groove, preferable an inch and a half thick.

Put in wall plates. Wall plates help mark out where each room and staircases are, and where toilets and sinks in upstairs bathrooms will be. Once your wall plates are added and framed, you can call the electrician and plumber to do their work.

Add trusses. Trusses support and strengthen the roof and consist of a network of beams. After you add the trusses and all of the electrical and plumbing work is complete, you can put the roof on the house and nail and screw in the sheetrock. At the same time, you can add the staircase of your choice.

Decorate the interior and exterior. Once all of the structural details are done, you can now add accents like flooring, painting, light fixtures and bathroom features. You need to find brick or siding to match the home.