We’re closing in on an answer to a question about a fixture of Chicago-area residential architecture: the two-flat.

Here’s the question, to remind you: 

Chicago-area two-flats straddle the line between apartments and homes. Who were they originally designed to serve? Has that changed?

Funny thing about these buildings, they’re so common in the city and inner-ring suburbs that it’s easy to forget they were designed for a specific market in mind. A scan of a Harris Brothers Co. advertisement makes a lot of how Design No. 144 can be a money-making proposition for the right owner. 

And the price for materials was right, or so they may have seemed more than a century ago: 

• Window shades for both floors: $14.75
• Paint job for all woodwork, outside, trim: $38.75 
• Double plumbing system: $155.50 

Stay tuned: Reporter Chris Bentley and The Chicago Architecture Foundation’s Jen Masengarb will have a lot to say on this soon.