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Photo of duplex from left sideDuplexes and duet homes are often confused with each other because both involve two attached residential units.  But legally and financially, a duplex is very different from a duet!

The photo to the right is of a San Jose home I sold a few years back.  You cannot tell from the image, but there is a front door off to the right of the single car garage door, and back around on the left side, near the double car garage door, there’s another front door. There are 2 units. It is a duplex or a duet home?  You cannot necessarily tell by looking!

What is a duplex?

A duplex is a multifamily home, in the same category as a triplex or fourplex, meaning there are multiple living units.  Most of the time, they are attached to each other, but not always. But what is truly distinctive is the way they are bought and sold.  With multifamily homes, such as a duplex, all of these dwellings are sold together. (The units are not sold separately.)

If you buy a duplex, you get both sides.  If you buy a triplex, you get three units. Sometimes an owner will live in one of the homes and renters are in the rest.  Many times, though, all of these multifamily homes are entirely leased out.  (Duplexes are usually 1 story and many of the duplexes in the San Jose area were built in the 1950s and 1960s, but you cannot tell from looking at it what the zoning and class of housing are with certainty.)  These types of properties are considered income producing or investment properties.

With a duplex, the property owner is responsible for all of the outside maintenance. Normally there are no HOA dues, because there is just one owner.

What is a duet home?

 A duet home is considered an attached single family home. It’s one unit which you can purchase. With duet homes, each side is sold separately. (It’s more like a townhouse with just 2 units.) Most of the time they are 2 stories, younger, and both sides are owner occupied and they are considered “attached single family homes” while a house is usually a “detached single family home”.  Although just as with a house, there could be a tenant in a duet home, it is not presumed to be an investment property.

Duet homes may have HOA dues, as some of these housing units are inside of a home owner’s association – there may be private roads, shared pools, etc. Or they could be just a community of 2 units, both responsible for their own side.

Duet homes will have something like HOA documents, though, so that there is a financial instrument for how to manage issues such as re-roofing, re-paving a shared driveway, etc. Sometimes there are annual dues collected so that the shared, larger expenses can be managed without a big financial surprise.

How do you know if a property is a duplex or a duet home?

The preliminary title report will provide how the home is zoned, but county records also state the type.

Is it possible to change the zoning and classification of housing?  Can a duplex become a duet home?  Possibly.  Sometimes owners will work to change the classification of the property. We see it especially with some former 4 plex units, McKeon built, which have been changed to condo ownership so that instead of one 4 plex, 4 distinct homes are sold (four condominiums). I know it can be done, but do not know how difficult it is to do it.

In Los Gatos, I knew of someone who purchased a parcel with two small houses on it and although they were not attached, they were “detached duplexes”.  I’d never seen that before!  Wisely, the owner of these two worked hard to change the classification and do a lot split – now there are 2 houses on 2 parcels and they are both single family homes, and worth more too.

Related reading:

What Is the Difference Between CID Ownership in a Condo, Townhouse or PUD?

Buy a Los Gatos home or real estate investment property(

San Jose Districts and The Values (

Rental property down payment



  • Mary Pope-Handy

    Silicon Valley Realtor, selling homes in Los Gatos, Saratoga, San Jose, Silicon Valley, and nearby since 1993. Prolific blogger with a network of sites.