Everything You Should Know About Adding a Second Story to a House

Find out everything you need to know about home additions, including the cost of adding a second story and staying in the same neighborhood.

Ripping the roof off your house and adding a second-story addition 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 to continue enjoying a setting that couldn't be duplicated 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.

Second-Story Remodeling Options

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 for adding a second story, and building regulations.

  1. Build from scratch: One option involves tearing off the roof and building a whole new upper level from scratch. This is likely what you would do 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 in.
  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.
pool and patio back yard exterior

Cost of Adding a Second Story

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. One reason your remodeling costs may be lower is that you won't have to do any foundation work (one of the more costly portions of any remodeling project) because you'll be building on your existing foundation. (You'll need to have the foundation checked, however, to make sure it can support the additional weight.)

Second, you may be able to save a bundle on roof construction by lifting off the existing roof with a crane in one or two large sections 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.

Third, 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 off 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. 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.

Embrace Your Neighborhood

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 the idea of selling and hunting for a new neighborhood that feels just as homey, consider staying put and installing a second-story addition 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.

This especially tends to be true of adding a second story to a ranch house and making a more substantial or striking architectural statement when viewed from the street. But often the intangible benefits are 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.

new home addition on red brick home in country
Jim Westphalen

More Reasons for a Second-Floor Addition

When creating your home remodeling plans, remember that adding a second story 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, using house additions is a good way to create extra privacy. It's also an opportunity to stretch out the main floor by making the walls several inches taller before adding the new level, and by merging or annexing smaller rooms to the downstairs that will no longer be needed when the new upstairs is done.

Design Tips for for a Second-Floor Addition

  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. Make windows match. Window size, shape, and placement in the new second story should coordinate with the existing story so 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.).

Frequently Asked Questions

  • How long does it take to add a second story to your house?

    Factors that will affect the time it takes to add a second story include, among others, permit applications, weather, material availability, and changes made to the plan. A full second story will take six to 12 months to complete, while adding a partial second story may take only half that time.

  • How do you know if your foundation can support a second story?

    The only way to be sure about the strength of your home's foundation is to hire an engineer to do a structural assessment of your home and determine what reinforcements will be needed to carry the additional weight of a second-story addition.

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