Do porches count toward floor area in Austin?

Last verified August 10, 2026 against the Austin Land Development Code · Kimbrough Gray · KiliGray Homes

An unenclosed porch does not count toward floor area at all, at any story, because gross floor area is enclosed space only. An enclosed ground-floor porch is exempt if it is not accessible by automobile and not connected to a driveway — capped at 200 sq ft if habitable space or a balcony sits above it.

Applies to: Single-dwelling lots of 5,750 sq ft or larger inside the Subchapter F boundary. Small lots and multi-unit projects have no dedicated porch exemption — no §3.3.3.A-style subsection exists there — but that is not the same as no relief: their gross floor area definition still excludes any unenclosed porch outright, and for duplex, two-unit and three-unit projects Code Interpretation CI2026-0002 confirms a porch with glass windows is treated as enclosed and does count.

Covered outdoor space	Counts toward floor area?	Provision
Unenclosed porch, any story	No	Not enclosed — §3.3.1
Open balcony or uncovered deck	No	Not enclosed — §3.3.1
Breezeway open on all sides	No	Not enclosed — §3.3.1
Enclosed ground-floor porch, no automobile access	No	Exempt — §3.3.3.A
…with habitable space or a balcony above	Above 200 sq ft	§3.3.3.A.2 caps the exemption
…accessible by automobile or connected to a driveway	Yes	Fails §3.3.3.A.1
Enclosed upper-story porch	Yes	Enclosed, and §3.3.3.A is ground-floor only

The first question is whether the space is enclosed. Only if it is does the §3.3.3.A porch exemption become relevant at all.

What the code says

Porches, basements, and attics that meet the following requirements shall be excluded from the calculation of gross floor area:

A. A ground floor porch, including a screened porch, provided that:
1. the porch is not accessible by automobile and is not connected to a driveway; and
2. the exemption may not exceed 200 square feet if a porch has habitable space or a balcony above it.

Austin Land Development Code · Read the full code

Ask whether it is enclosed before anything else

Since 2008, gross floor area is enclosed space that is not exempted. An open porch is not enclosed, so it never enters the calculation — there is no exemption to claim and no condition to satisfy.

This is a change from how the code used to work, and from how a lot of published advice still describes it. Until 2008 the code counted the roofed portion of a second or third story, including porches. That provision was struck.

The §3.3.3.A porch exemption exists for the case where a porch is enclosed — most commonly a screened porch, which the code names — and it carries real conditions.

One line worth confirming. The rule turns on whether a porch is enclosed, and the code does not define where screening crosses that line. A fully screened porch is treated as enclosed and needs this exemption; an open porch with insect screening on one side is a judgment call. If your design sits near that line, confirm it with Development Services before you rely on either answer.

The two conditions on an enclosed ground-floor porch

1. Not accessible by automobile, not connected to a driveway. This closes an obvious route — calling a space a "porch" when it functions as covered parking. If a car can reach it, it is not a porch for these purposes.

2. The exemption caps at 200 sq ft if habitable space or a balcony sits above it. An enclosed porch on its own softens the street elevation. Put a room or a balcony on top and you have added the mass the ordinance exists to control, so the relief is limited.

Read that second condition carefully: it caps the exemption, not the porch. A 300 sq ft enclosed porch with a bedroom above still gets 200 sq ft of relief — the remaining 100 counts.

Small lots, and duplex/two/three-unit projects: a different rule, not no rule

§3.3.3.A above is Subchapter F only. Small lots under §25-2-779 and duplex, two-unit and three-unit projects under §25-2-773 have no comparable enumerated porch exemption — but their gross floor area definitions are enclosure-only, the same as Subchapter F's, so an unenclosed porch is outside the count before the question of an exemption ever arises. There is no automobile-access test and no 200 sq ft cap to satisfy, because there is nothing to exempt: the porch was never counted.

For duplex, two-unit and three-unit projects, City staff interpretation CI2026-0002 (May 2026) adds one clarification worth knowing: a porch with glass windows is treated as "enclosed" under the §25-1-21(40) definition, and an enclosed porch counts in full — there is no 200 sq ft relief valve like §3.3.3.A.2 to fall back on. A screened porch, by contrast, is generally not enclosed under that definition, since a screen is not glazing. No comparable staff interpretation exists for small lots under §25-2-779; this page states only the ordinance text for that regime and goes no further.

How this plays out on a real lot

Open covered outdoor space is the best value in the code. A deep front porch, a breezeway between house and garage, a covered upstairs balcony left open — none of it enters the floor area calculation, and all of it is usable for most of the Austin year.

The trap is the late change. Screening a porch for mosquitoes turns unenclosed space into enclosed space, and now it needs the §3.3.3.A exemption and has to satisfy both conditions. That is worth deciding at design stage rather than discovering afterwards. On a duplex, two-unit or three-unit project under §25-2-773, the equivalent trap is glazing — adding windows to a porch to keep weather out converts it from free space to counted space, with no cap to soften the cost.

Common questions

Does a covered patio count toward FAR in Austin?

On the ground floor, no — §3.3.2.A excludes a ground-floor porch, and a covered patio is treated the same way. On an upper story, a roofed covered area is included.

Does a screened porch count toward floor area?

Not on the ground floor. §3.3.2.A names screened porches explicitly in the exclusion.

Does a second-floor balcony count toward floor area in Austin?

If it is covered by a roof, yes. §3.3.1.A includes the roofed portion of a second or third story, including porches.

Is there a size limit on the ground-floor porch exemption?

The exclusion in §3.3.2.A carries no square footage cap. Other limits still apply — setbacks, building coverage and impervious cover all constrain how large a porch can be.

Do porches count toward floor area on a duplex, two-unit or three-unit project?

Only if enclosed. §25-2-773 counts only enclosed area, so an unenclosed porch is outside the calculation entirely. Code Interpretation CI2026-0002 confirms that a porch with glass windows is treated as enclosed and does count — with no 200 sq ft relief like the Subchapter F exemption carries.

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We are homebuilders, not the City of Austin. This page explains how we read the code in practice — it is not legal advice and it is not an official determination. Always confirm with Austin Development Services before you rely on it for a project. The authoritative text is the Austin Land Development Code; permitting questions go to Austin Development Services Department.