GLA rules · 4 min read
Do Covered Porches, Patios, or Decks Count as GLA?
The short answer is no — covered porches, screened porches, open patios, and decks do not count as Gross Living Area (GLA) under ANSI Z765-2021. This is one of the most common sources of inflated square footage in MLS listings, and one of the first things a licensed appraiser will correct.
What ANSI Z765 requires for GLA
Under ANSI Z765-2021, a space must meet all of the following criteria to count as GLA:
- Above grade — the finished floor must be at or above the exterior ground level on all sides.
- Fully enclosed — the space must have permanent walls, not just a roof or screen.
- Finished — walls, floors, and ceilings must be finished to typical residential standards.
- Heated — the space must be connected to the home's heating system.
- Adequate ceiling height — at least 7 feet, or for sloped ceilings, at least half the area must meet the 7-foot threshold.
Covered porches, patios, screened porches, and decks typically fail on at least two of these criteria: they are not fully enclosed, and they are not heated.
Space-by-space breakdown
| Space type | Counts as GLA? | Notes |
|---|---|---|
| Open deck | No | No roof, not enclosed, not heated |
| Covered porch (open sides) | No | Has roof but not enclosed or heated |
| Screened porch | No | Not fully enclosed, not heated |
| Enclosed porch (heated, finished) | Potentially yes | Must be fully enclosed, finished, and heated — verify ceiling height |
| Four-season sunroom (heated) | Potentially yes | See sunroom rules — must meet all GLA criteria |
| Open patio | No | No roof, not enclosed |
| Covered patio | No | Has roof but not enclosed or heated |
| Attached garage (finished) | No | Garages never count as GLA regardless of finish |
The enclosed porch exception
A porch that has been fully enclosed with permanent walls, connected to the home's heating system, and finished to residential standards may qualify as GLA — but this is the exception, not the rule. The key questions:
- Are all sides enclosed with permanent walls (not screens or temporary panels)?
- Is the space connected to the home's HVAC system?
- Is the ceiling height at least 7 feet throughout?
- Are floors, walls, and ceiling finished to residential standards?
If yes to all four, an enclosed porch likely qualifies. If any answer is no, it does not count as GLA — but should still be reported and valued as a contributing amenity.
Why this matters for appraisals
Licensed appraisers are required to report GLA and non-GLA areas separately. A covered porch gets measured and noted in the report, but it is not added to the GLA line. When selecting comparable sales, appraisers will adjust for the difference between homes with and without significant outdoor living areas.
The practical implication: a 2,000 sq ft house with a 400 sq ft covered porch is not the same as a 2,400 sq ft house for appraisal purposes. The covered porch adds value — but it is measured and valued separately.
Measuring covered porches in PlanSnapper
When tracing your floor plan in PlanSnapper, do not include covered porches, screened porches, or decks in the main GLA polygon. Use a separate polygon to measure them and label it appropriately in your notes.
PlanSnapper supports multiple polygons per project, so you can measure GLA and non-GLA areas in the same session and export both numbers.
Related articles
- Sunrooms and screened porches: GLA rules
- What counts as GLA?
- How to measure a garage for an appraisal
- What is ANSI Z765?
- Screened porch square footage appraisal
- Deck and porch square footage: what appraisers count
- GLA vs Total Square Footage: What Is the Difference?
- ANSI Z765 vs BOMA: Square Footage Standards Compared
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