Want to Build a Second-Story Addition? Here's Everything You Need to Know (2024)

Ripping the roof off and adding a second story to a house might sound like a drastic means of gaining space, but a total home makeover makes sense in various situations. In some cases, second-story addition plans could be a big money-saver. In others, the real payback is something you can't put a price on: the ability to stay in the neighborhood you've lived in for years or continue enjoying a setting you can't recreate elsewhere. Use this guide to learn how to build a second floor on an existing house and the requirements and costs that come with it.

Options for Adding a Second Story to a House

There are at least four ways to expand vertically during your home renovation. How you go about your second-story addition plans depends on your preferences, foundation requirements, and building regulations.

1. Build from scratch: One option involves tearing off the roof and building a whole new upper level from scratch. You would likely do this if you're adding a second story to a ranch-style house.
2. Replace roof: Another is to sever the existing roof around the edges and lift it off temporarily, then put it back in place after the new level has been framed.
3. Expand: The third tactic for your house addition is to expand an upper level out across an existing one-story section, such as a flat-roof garage or porch.
4. Modular Designs: A modular second-story addition is designed and built off-site and brought, fully built, to your existing home. It is often the quickest and most cost-effective way to add a second story to your home.

Budget Benefits of Adding a Second Story to a House

If you need to add a sizable amount of space (several rooms rather than just one or two) but are faced with a tight budget, adding up may be your smartest option. Adding a second story starts at around $65,000 for one room and can go as high as $600,000 for more elaborate work. The average cost for adding a second story to a house is $100 to $300 per square foot.

Skip the Foundation

Your remodeling costs may be lower because you won't have to do foundation work (one of the more costly portions of any remodeling project) since you'll be building on your existing foundation. (However, you'll need to have the foundation checked to ensure it can support the additional weight.)

Raise the Roof

You may save a bundle on roof construction by lifting off the existing roof in one or two large sections with a crane and reinstalling it on the new second story. Renting a crane can be expensive, but it's much cheaper than building a whole new roof from scratch.

Get it Done More Quickly

Adding a new level that fits on top of your home's existing footprint means you'll double its square footage in a matter of days (the length of time needed to frame and "weather" in an upper level). After that, you can finish the new space all at once or room by room, as your remodeling budget allows. And if you're handy, you might be able to do most of this work yourself.

Add Value to Your Home

If the new rooms are simple spaces and you use inexpensive finishes, the total second-story addition cost for these types of house additions could be about half that of a conventional ground-level addition of the same size. Plus, adding a second story will increase the value of your home by approximately 65%, which is the most significant return on investment of any home addition you can do.

Stay Where You Are by Adding a Second Story to a House

For many families, location is everything. As the country's metro areas sprawl and the cost of buildable land skyrockets, the convenience and charm of a well-established neighborhood often become irreplaceable. If you have little or no room to expand laterally but dread selling and hunting for a new neighborhood that feels just as homey, consider staying put and adding a second story to your house instead.

Even if your home remodeling plans are more elaborate than simply adding raw square footage as cheaply as possible, creating a much larger house within the same footprint can net considerable benefits—financial as well as personal. In highly desirable older neighborhoods, houses that double in size are likely to double or triple in home values much faster than those in some of the newer, less convenient areas.

Adding a second story to a house and making a more substantial or striking architectural statement when viewed from the street is one of the best ways to increase a home's value. Still, the intangible benefits are often the real reward. You can hardly put a price on being able to look out your windows at the backyard where your children have played in the sprinkler or at the huge shade tree you planted with your own hands when you first moved in. A second-story addition can secure that for you.

More Reasons for Adding a Second Story to a House

When creating your home remodeling plans, remember that adding a second story to a house makes sense if your lot is small and you want to preserve as much open space outdoors as possible for gardening, outdoor living, or simply an adequate sense of separation from neighbors. Or your yard may include some landscape features you don't want to give up, such as a grand old shade tree, a tall hedge, or a picturesque wisteria-draped pergola.

If your family is experiencing growing pains, house additions are a good way to create extra privacy. They're also an opportunity to stretch out the main floor by making the walls several inches taller before adding the new level and merging or annexing smaller rooms to the downstairs that will no longer be needed when the new upstairs is done.

Design Tips for Adding a Second Story to a House

1. Avoid awkward massing. Doubling the height of a plain, rectangular house can create a boxy effect. Offset it with roof pitches, overhangs, porches, and trim details.
2. Deal with height restrictions. Local building codes may restrict the height of ridgelines for houses in your neighborhood. Check with your city officials before you draw up the plans.
3. Provide adequate structural support. Some types of house foundations can't support a multilevel structure, so you should always check the foundation requirements for adding a second story. Also, rafters in a one-story house usually aren't strong enough to double as floor joists for a second story. Have a structural engineer evaluate your home's foundation and framing before you begin planning the new level.
4. Match the windows. The new second story's window size, shape, and placement should coordinate with the existing story so that openings line up or form pleasing patterns on each exterior wall from top to bottom.
5. Maintain pleasing proportions. Skimpy proportions that are unnoticeable on a small one-story house often become detracting when such a house doubles in size. Keep the individual elements of your house—such as windows, trim, eaves, shutters, columns, and dormers—in proportion with its new overall size by beefing them up or giving them extra visual emphasis (accent colors, contrasting finishes, etc.).