Ask David: Does NorthstarMLS Have a Field for Accessory Dwelling Units (ADUs)?

Accessory dwelling units (ADUs) and secondary living quarters are features buyers may look for when searching for a property. But how do you identify these features when entering a listing or searching for properties in NorthstarMLS? 

While NorthstarMLS does not currently have a field specifically labeled “ADU,” there are several existing fields that can help you identify and search for Single Family properties with additional living quarters. 

Let’s look at the options available. 

What Is an Accessory Dwelling Unit (ADU)?

An accessory dwelling unit, commonly referred to as an ADU, is generally an additional living space or secondary residential unit located on the same property as a primary residence. ADUs are typically associated with Single Family properties and may be attached to the main home or located in a separate, detached structure. 

Depending on the property, these spaces may include separate living areas, bathrooms, kitchens or other features that allow for additional living accommodations. 

Because ADUs can take different forms, it’s important to understand which NorthstarMLS fields may help describe these features. 

Listing Input: Fields to Consider

When entering a Single Family listing in NorthstarMLS, there are two fields that may be helpful in identifying additional living quarters or secondary units. 

Second Unit

The Second Unit field includes two selections that may be useful when describing additional living quarters within a single-family property: 

• Existing In-Law w/Bath 

• Existing In-Law w/Kitchen 

These selections can help identify properties that have additional living accommodations, particularly when a separate bathroom or kitchen is present. 

Searching for these properties: When using your MLS search system, locate the Second Unit Type search field. From there, you can select either or both options to help find properties with these features.

Outbuildings

Another field to consider is Out Buildings, particularly when the additional living space is in a separate structure on the property. 

Two available selections include: 

• Guest House 

• Second Residence 

While these options do not necessarily indicate that a property has an ADU, they can help identify properties with additional residential structures that may be of interest to buyers. 

Searching for these properties: Locate the Outbuildings search field in your MLS system and select Guest House and/or Second Residence as part of your search criteria. 

Don’t Forget About Remarks! 

In addition to the predefined listing fields, the Remarks field can be another useful place to describe additional living quarters or features that may be considered an ADU. Listing agents can include descriptive terms such as “accessory dwelling unit,” “ADU,” “in-law suite,” or “secondary living quarters” when those descriptions accurately reflect the property. 

When searching, you can also use the Remarks search functionality to look for these terms. 

Keep in mind that searching Remarks may require a little more effort than using the predefined field selections. Because agents may describe these spaces differently, you may need to try multiple keywords to find relevant properties. 

Tip: When entering a listing, consider using both the applicable listing fields and descriptive language in Remarks. This can help make these features easier for other agents to identify when searching. 

A Reminder About Square Footage and Listing Rules

When a property includes additional living quarters or a secondary unit, it’s important to follow NorthstarMLS listing rules, particularly when reporting finished square footage. Not all additional living spaces should automatically be included in the finished square footage of the primary residence. Be sure to review the NorthstarMLS guidelines for reporting finished square footage, including how secondary units should be handled. 

It’s also important to remember that an ADU is not necessarily the same as a property with multiple dwellings, acreage or commercial components. Different property configurations may have different listing requirements. 

For additional guidance, check out this article: 

Have Listings with Land, Multiple Dwellings, or Commercial Components? Here’s Some Listing Rules for You! 

What About a Dedicated ADU Field? 

We recognize that ADUs and secondary living spaces are important property features, and having consistent ways to identify them can make listing input and searching easier. 

NorthstarMLS continually evaluates its listing data fields and opportunities for improvement. We also work with the Real Estate Standards Organization (RESO) to stay aligned with industry data standards and explore potential enhancements. 

As these standards and industry needs evolve, we’ll continue evaluating how we can best support these types of property features in NorthstarMLS. 

The Bottom Line

While there isn’t currently a dedicated ADU field in NorthstarMLS, you do have several options available to help identify and search for properties with additional living quarters. The Second Unit, Outbuildings and Remarks fields are all worth considering, depending on the property and its features. 

For listing agents, using the appropriate field selections and providing clear descriptions can help make these properties easier to find. For agents searching on behalf of buyers, combining these search options may help uncover properties that might otherwise be missed. 

And as always, be sure to follow NorthstarMLS listing rules when reporting square footage and determining how additional living spaces should be represented. 

Need Help? 

For questions, contact the NorthstarMLS Help Desk at help@northstarmls.com or call 651-251-5456. For MLS compliance, contact the Rules and Regulations department at rules@northstarmls.com or call 651-251-3210.