Coach houses, typically small dwellings located in the rear of a property, served an important purpose in the early 20th century: They created additional (and typically affordable) housing for workers and extended family members. And while they’re not exactly rare in Chicago, you aren’t going to find any built in recent decades as the city’s zoning ordinance prohibits new accessory dwellings.

Fortunately, coach houses that were built before this 1950s zoning change are grandfathered, and homeowners can use these as an income-producing apartment. There is one major exception, however: Any 12-month lapse in occupancy will, in effect, make it illegal to rent out a coach house again. Additionally, if a coach house is demolished or lost in a fire, it cannot be replaced.

The vacancy code means that there are usually a number of Chicago coach houses listed for sale or rent. Here are just a few examples around the city.

3032 N. Seminary Ave. Unit CH, $414,900

In parts of Lincoln Park and Lake View, coach houses are sometimes sold separately from the main home. This is unusual in the sense that it seems to contradict existing zoning standards, but this 1,600-square-foot coach house dwelling on Seminary Avenue is a perfect example.

5058 W Carmen Ave., $440,000

What’s better than a classic Chicago red brick bungalow? A classic Chicago bungalow with a coach house in the rear. For under $450,000, this Carmen Avenue property includes a two-unit bungalow and a detached third unit located behind it.

2224 W. Farragut Ave., $494,900

Here’s a unique opportunity to get a vintage single-family home and coach house on an oversized lot in Lincoln Square. Clad in cedar shake siding, the adorable coach house would make for a perfect in-law suite or rental dwelling, and there’s still plenty of room in the backyard for everyone to share.

2144 W. Wilson Ave, $875,000

Home shoppers may be able to stretch their budget a bit further if they consider the potential income from leasing out a coach house. While this vintage Victorian farmhouse may be out of reach for some buyers, renting the detached rear dwelling could help get better financing and cover the bills.

1416 N. Greenview Ave., $969,000

Anyone who’s lived in or spent time visiting the greater West Town area is likely to recognize this style of coach house. The modest dwelling is no mansion, but it’s a more affordable option for renters and an income-producing asset for the homeowner. And up in the front is a two-unit building.