Why Nearly Every Chicago Home Has a Basement … And What You Can Do With It


A basement isn’t a necessary element of an American home but in the midwest they are nearly ubiquitous.  This underused space under your house could be the easiest (and most cost-effective) way to expand your living space (much more so than building up from the attic or expanding out into the back yard.  

Why do Chicago Homes have Basements

If you’ve ever looked at a weather map, you know that its generally warmer in the south and west of the US and colder up north.  That’s true on any given day and during the winter summer shifts as well.  Cold weather above ground translates to freezing soil below the surface and the colder the air, the deeper the frozen ground.  The freeze thaw cycle that take pace in that frost region can crack a concrete building foundation so its important to dig the foundation for any building down below the typical frost line.


As the map shows, the typical frost depth in our region is pretty deep – specifically, in Chicago its around 4 feet.  Excavating four feet of soil out from under a new building takes a lot of equipment and effort – but once you’ve begun, it takes only a little more to dig down a few more feet and have enough headroom for a whole ‘nother level of the house.  Or better yet, dig down just those required 4’ and then set the “ground floor” a few feet above ground level.  That makes room for a few light-sharing widnows into the basement and gives an extra measure of privacy to the first floor windows.

The perfect depth of a Chicago basement is a pretty specific target to hit – low enough to be under the frost line (see below) but high enough to stay above the water table.  Dig too deep – or sit through a very wet period – and you can end up with a flooded basement.

Typical Chicago Basements

A full basement (partially exposed above ground level) is an almost universal feature of a Chicago home or residential building.  It is a defining element of both Chicago Bungalows (which used the basement space as a storage area for future conversion to den space or extra bedrooms).  In the slightly older Greystone type, the basement served as more of a utility space, housing the building boiler and probably coal storage as well as other out-of-the-living-space needs.  See the basement windows peaking out just above ground level in these Bungalows?chicago building type: bungalows

Its also used in many older multi unit buildings as well.  The Courtyard Apartments found all over the North Side use a partially submerged basement to connect all the units to shared storage and laundry facilities while, above ground, each group of six units is accessed by vertical stair case rather than connected hallway.

The Chicago Four-Plus-Ones use the technical definition of a “basement” within the city zoning code to sneak in a little extra area .  Since the city allowed for occupied floors and a basement (all capped below a height restriction), the designers of these buildings tucked the entrance lobby and a building-footprint-allotment of parking just a few feet before street level and labeled them “basement”, then constructed four floors of apartments above – hence their name.

What to do with the Basement

Most basements are left unfinished at the time of construction –  either intended for nothing but storage and foundation stability, or simply waiting for new inspiration and funds to be finished off.  Especially in older homes, such as the Chicago Bungalow type, they can serve a valuable purpose of creating a den or rec-room to offset the more public nature of a formal living room upstairs.  They can be space for a hobby or projects, or even a guest or additional bedroom.

One way to make those basement spaces even more pleasant to be in is to remove the existing concrete floor and dig down to the base of the foundation – creating a few extra inches of valuable head room, as was done in the building drawn at the top of the post.  Re-pouring the concrete floor also gives an opportunity to embed heating tubes – a radiant heating method that will help warm the entire house efficiently.  Choosing to expand living space into the basement can reduce the need for other additions, moderating the amount of green space lost to buildings.  And no part of a home feels cosier and more secure than a well-designed basement den.  The possibilities are many.

Moss has several upcoming project which include an extensive basement transformation.  Stay tuned for more details over the months to come.  


  • Lethe

    Wait, I think I missed something. Wouldn’t digging down to increase the existing basement space increase the risk of flooding? Particularly in light of the loss of neighborhood green space to absorb storm water due to the paving over of back, side and front yards by those wanting to build larger and larger warehouse-type homes? I know several folks who went with ‘garden units’ in newer condo buildings and periodically get water in their homes. You yourself point out that “The perfect depth of a Chicago basement is a pretty specific target to hit – low enough to be under the frost line (see below) but high enough to stay above the water table. Dig too deep – or sit through a very wet period – and you can end up with a flooded basement.” Developers push that lower limit to squeeze a few more condos into a new building, and you seem to be encouraging homeowners to do the same. What have I missed?

    • Thanks for the comment, Lethe. The water table is a complex issue since it fluctuates and varies greatly by location in the City. We have some projects on ridges that have never been flooded. In any event, adding a foot or two of depth to the basement will not have a great impact on the likelihood of a flood in the basement. The best way to mitigate water intrusion is proper dampproofing, drain tiles/sump pumps and having as much pervious surface around the building as possible. Its ironic the the increase in impervious surfaces has the possibility of reducing the local water table, since water that sheds to the street and sewer ultimately ends up in St. Louis and not recharging our local groundwater. Just ask California.

      • Lethe

        Hi, Matt. I happen to live in an old condo-conversion – a century-old building converted in the 1970’s. I’ve lived here for almost 20 years. We never had a single drop of water in the basement until…well, you guess when. Nah, I’ll tell you. Since the City ‘improved’ the sewers on our street three years ago, we’ve flooded four times, the corner of our street looks like the confluence of the Missouri and the Mississippi ever time it rains (yes, EVERY time), and rather than taking in that water, the sewers on the street have been seen to geyser water up into the air at least a foot (that’s usually a warning sign to check for water in the basement). I don’t know how all this is working together – the ‘improved’ sewers, the lessening of what you are calling pervious surfaces (I still call it green space), and the increase in the amount of precipitation one storm lets loose – but it is a mess. Since I have you here, what’s your opinion on standpipes as a possible solution to the stormwater that now backs into our basement from the drains?

  • Lukalost

    I grew up here in south Texas where basements are unheard of. However, there is one 1927 house in Corpus Christi, TX that has a full finished basement and it’s only blocks away from the Gulf of Mexico! Also there are a small handful of houses on Houston’s west side that have wine cellars and some have full basements also but they’re mostly very old houses. I didn’t become familiar with basements until I moved to Atlanta, and even then most houses didn’t have basements and the ones that did were mostly the daylight variety. I’ve always been fascinated by northern latitudes and the geology. I visited Chicago for the 1st time last March. Even though it was chilly I loved every minute of it. I thought people in Chicago would be mean, (that’s what I was told) but that was not the truth, in fact most people I encountered were warm and down to earth. I fell in love with the northwest suburbs particularly in DuPage county. One thing I noticed is that pretty much all houses had basements and they were mostly the look-out type. I found this very fascinating. However I didn’t realize that there was a risk of flooding if you dig too deep until I read these comments; I thought that was only a Houston phenomenon, LOL!


    • Laura Cripe

      We’re only crabby in the winter. Otherwise, our Midwestern chill personaility is fairly consistent. Happy to hear you enjoyed our City by the Lake and that you had a chance to check out the burbs as well; there are many beautiful natural areas in all the surrounding suburbs, which is a lovely respite. Ah, yes the pesky flooding. Those with basements have an ongoing battle with flooding and homeowners keep the sump pump manufacturers in business. The basement culture is interesting and they host a variety of uses from broom hockey (fun for the whole family, especially in winter), lobster racing, wood shops, root cellars and my favorite – wine cellars! Cheers!