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.