Basement vs. Foundation: Understanding the Difference in NorthstarMLS Listings

When entering a listing in NorthstarMLS, it’s easy to assume that Basement and Foundation refer to the same thing. While they’re closely related, they describe two different aspects of a property, and both play an important role in helping agents and buyers accurately understand a home’s construction. Here’s what each field means and how to choose the most appropriate options when creating your listing. 

What Is the Foundation?

The Foundation describes how the home is supported by the ground. It’s the structural system that transfers the weight of the home to the earth.

Foundation details listed in Add/Edit include: 

• Brick/Mortar
• Combination
• Concrete Block
• Concrete Perimeter
• Insulating Concrete Forms
• Permanent
• Pillar/Post/Pier
• Poured Concrete
• Raised
• Slab
• Stone
• Wood
• Other
• See Remarks
• None

Think of the foundation as what the house is built on. For example: 

• A home built on a slab has a Concrete Slab foundation.
• A rambler with a full basement may have a Concrete Perimeter foundation.
• An older farmhouse may have a Stone foundation.

What Is the Basement?

The Basement describes the space below the main living level and how that space is finished or used. Unlike the Foundation field, subscribers can select multiple Basement options to accurately describe the lower level. 

Basement details include: 

• Concrete Block 
• Crawl Space
• Daylight/Lookout Windows
• Drain Tiled
• Drainage System
• Egress Windows
• Finished (Livable)
• Full
• In-floor Heat
• Kitchenette
• Owner Access
• Partial 
• Partially Finished
• Shared Access
• Single Tenant Access
• Storage Space
• Storage Locker
• Sump Basket
• Sump Pump
• Tile Shower
• Tray(s) Ceiling
• Unfinished
• Walkout
• Wood
• Other
• None 

These options help tell the story of the lower level, not just whether one exists, but how it functions.

Why Both Fields Matter

Although they sound similar, the fields answer different questions:
Foundation: What supports the home?
Basement: What type of lower level does the home have?

For example:
Example 1 

• Foundation: Concrete Perimeter
• Basement: Full, Finished, Walkout, Drain Tiled, Sump Pump 

Example 2 

• Foundation: Concrete Slab
• Basement: None 

Example 3 

• Foundation: Concrete Block
• Basement: Partial, Unfinished

Each combination provides valuable information for buyers, appraisers, inspectors, and cooperating brokers.

Tips for Accurate Data Entry

When completing these required fields: 

• Describe the foundation based on the home’s structural support, not the finished space below grade.
• Select all Basement options that apply. The Basement field is designed to capture multiple characteristics of the lower level.
• If a property has no basement, choose None in the Basement field while still selecting the appropriate Foundation type.
• If you’re unsure of the home’s foundation type, review available property records or consult the seller before entering the listing.

In Support of High-quality Data

Accurate listing data improves the experience for everyone. Buyers can search more effectively, appraisers and inspectors have better information, and fellow REALTORS® can more confidently evaluate a property before scheduling a showing. Taking a few extra moments to distinguish between a home’s foundation and its basement helps ensure your listing accurately represents the property and maintains the high-quality data that NorthstarMLS subscribers rely on every day. 

Still have questions about foundations and basements?

The NorthstarMLS Rules + Regulations team is here to help with any questions you have. Contact us today!