FAQ · 5 min read

Does a Sunroom or Screened Porch Count as GLA?

This is one of the most common gray areas in residential appraisal. The short answer: screened porches do not count. Sunrooms sometimes do — but only if they meet specific requirements under ANSI Z765.

The ANSI Z765 test for GLA

Under ANSI Z765, a space counts as Gross Living Area if it meets all of the following:

• Above grade (not below ground level)
• Finished (walls, ceiling, and floor completed to a residential standard)
• Directly accessible from the main living area
• Heated to the same standard as the rest of the home
• Minimum ceiling height of 7 feet (for at least 50% of the floor area)

The heating requirement is what eliminates most screened porches and many three-season rooms. If the space is not conditioned year-round to a habitable temperature, it does not qualify as GLA regardless of how finished it looks.

Screened porches: never GLA

A screened porch is open to the exterior through the screens. It is not a conditioned, enclosed space. Even if it has a ceiling fan, lighting, and tile floors, it does not meet the ANSI Z765 definition of GLA.

Appraisers report screened porches separately — typically as a line item contributing value as an amenity, not as square footage. A large, well-finished screened porch on a desirable property absolutely adds value. It just does not add GLA.

Sunrooms: it depends

Sunrooms exist on a spectrum. Here is how to think about each type:

• Three-season room (no HVAC): Not GLA. Even with full glass walls, flooring, and drywall — if it lacks year-round heating and cooling connected to the central system, it does not qualify.
• Four-season sunroom (with HVAC, insulated walls): Likely GLA if it meets all other ANSI requirements. The appraiser must verify the heating source is permanent and adequate, not a space heater.
• Converted porch with mini-split: Gray area. A mini-split provides conditioning, but the appraiser needs to assess whether the finish level, insulation, and connectivity to the main house support inclusion in GLA. When in doubt, document your reasoning and be conservative.
• Sunroom square footage appraisal: what counts
• Screened porch square footage appraisal

What about Florida rooms and Arizona rooms?

Regional terms like "Florida room," "Arizona room," or "Carolina room" describe similar additions — glass-enclosed spaces attached to the home. The GLA determination follows the same test: is it conditioned, finished, and accessible? Many are not — they are climate-specific living spaces used seasonally rather than year-round conditioned areas.

In warm climates, appraisers sometimes see these rooms included in GLA in county records even though they do not meet ANSI Z765. Always apply the standard rather than deferring to the tax record.

How to report it when it does not count as GLA

When a sunroom or porch does not qualify as GLA, appraisers typically note the square footage and condition in the "other improvements" section of the report and make adjustments based on comparable sales with and without similar features.

Never just include it in the GLA total and move on. If a reviewer or underwriter later questions the count, you want documentation that you consciously considered and excluded the space based on ANSI standards.

Using PlanSnapper with sunroom floor plans

If you are working from a floor plan that includes a sunroom, PlanSnapper lets you trace the main living area perimeter separately from the sunroom. You can measure both areas and report them independently — GLA for the main house, sunroom square footage as a separate data point.

Related: What counts as GLA? · Ceiling height requirements · Bonus room above garage

Compare: GLA vs Total Square Footage: What Is the Difference? · ANSI Z765 vs BOMA: Square Footage Standards Compared