ADDING A SECOND FLOOR: Are You Sure About That?

If your foundation isn't able to support a second floor,
are you ready to do this?

Time and again, couples will ask me over for a consultation and happily declare, “We want to add a second story to our house!”  Right then, my heart sinks, and I think to myself:  Rats. I have to spoil the party again.  

Why? More often than not, adding a second story is more complicated and less satisfactory than adding on at ground level. If you’re thinking about “going up”, there are a number of serious issues to consider.

Stairs crammed in a closet or
wiping out a bedroom won't do
your resale value much good.

First and foremost, is your existing foundation up to the task?  The foundations of most single-story homes weren’t designed to carry the additional weight of a second floor. Years ago, this wasn’t such a big deal, because building departments were fairly lax about enforcing foundation requirements—that’s why you see so many rinkydink old houses with obvious second-floor additions. But earthquakes and lawsuit-mania have changed that. Nowadays, most building departments require detailed engineering calculations to demonstrate that your existing foundation is capable of supporting an additional story.  

If it isn’t, your only alternatives are to reinforce your present foundation, or to replace it with one designed to carry two stories. Both are expensive propositions. Foundation replacement, for example, requires that your house be supported on cribbing while the contractor demolishes the old foundation and pours a new one. This in turn usually requires that the landscaping and paving around your house be dug up as well.  Not quite what you had in mind, huh?

Many home styles weren't meant to be tall and spindly—
as you can seen from this example.
(Courtesy Chicago Bungalow Association)

Even if your foundation is adequate, adding a second story doesn’t always make architectural sense. For example, if the new interior stairs can’t be properly incorporated into the existing floor plan, a ground-floor addition may be a better solution. A steep staircase that’s crammed into a closet, or one that wipes out half a bedroom, may actually hurt your home’s resale value despite the extra space gained. 

What’s more, a small second-story addition will generally be more expensive in relation to the amount of floor space added. That’s because the stairs consume a big chunk of floor space on both the first and second floors—space that has to be recaptured in the addition. Hence, a small second story addition is seldom worth the trouble.  

The proverbial second-floor addition that "fell out of the sky",
crushing this poor little rancher.

As for aesthetics—more bad news. Many home styles, such as bungalows and ranch-style homes, were meant to be long and low. On such homes, a second story can look gawky and foreign, as if it just dropped out of the sky.      

If all this isn’t enough to think about, zoning and design ordinances in a few areas restrict or even forbid a second story addition, so check them out carefully too.  

However, since you've stuck with me up to this point, I'm happy to say that there are a number of instances in which a second-story addition makes sense. If your foundation is adequate, your zoning checks out, and there’s room to accommodate a staircase without disrupting the lower floor plan, then going up may be just the ticket.  If your foundation needs replacement anyway—say, due to seismic requirements or damage from settlement—then the extra effort necessary to bring it up to two-story standards will be nominal, and a second-floor addition may be worthwhile.  Lastly, of course, if your site doesn’t have any room for a first-floor addition, you may not have any choice in the matter.