Screen Room vs Sunroom vs Florida Room, Decoded.

The Three Names, Defined

The fastest way to settle the screen-room-versus-sunroom-versus-Florida-room debate is to stop treating them as styles and start treating them as code classes. A screen room is an open or insect-screened enclosure with no glass and no climate control. A Florida room is glass-enclosed but typically unheated, used three seasons a year. A sunroom, in the strict sense, is heated and cooled like the rest of the house.

Builders and listing agents use the three words loosely, which is exactly why homeowners get surprised at permit review and again at appraisal. The Florida Building Code does not care what the brochure calls the room — it classifies the room by how it is enclosed and whether it is conditioned, then attaches permitting, energy, and habitability consequences to that classification.

Why the label is a contract, not a description

Each name implies a different envelope. Screen keeps out insects; glass keeps out rain and wind but not temperature; an insulated, conditioned wall assembly keeps out the Florida climate entirely. Those are escalating levels of construction, and the price of admission rises with each step in the form of code requirements, not just materials.

The AAMA/NSA 2100 Ladder

Every glass-or-screen room in Florida is graded by one referenced standard: AAMA/NSA 2100, the Specifications for Sunrooms published by the National Sunroom Association. It defines five categories, and the Florida Building Code adopts them by reference in its aluminum chapter, so a permit reviewer is reading the same ladder you are.

The categories climb on three variables: whether the room is thermally isolated from the house, whether it is conditioned (heated or cooled), and whether it is habitable. Those three questions, answered in order, place every enclosure on exactly one rung.

The five categories at a glance

Mapping the three common names onto this ladder is the whole article: a screen room is Category I, a glass Florida room is Category II or III, and a true conditioned sunroom is Category IV or V. The diagram below turns that mapping into the decision a homeowner actually faces.

Which One Actually Has Air Conditioning

A Florida room does not, by definition, have air conditioning; a sunroom does. This is the single most common point of confusion, because many Florida rooms have a window unit or a portable AC bolted on after the fact. That retrofit keeps the space usable in July, but it does not change the room's code category — and the code category is what counts.

The reason is thermal isolation. Thermal isolation means the room is separated from the home's conditioned envelope by a code-compliant wall and fenestration, so it can be on its own temperature control without dragging down the efficiency of the house. AAMA/NSA 2100 Category IV is exactly that: conditioned, but isolated. Category V removes the isolating wall and ties the room into the main system, which is why it — and only it — is treated as habitable space.

Three signs a room is genuinely conditioned

• Permanent ductwork or a mini-split fed by the home system, not a plug-in appliance.
• An insulated, code-compliant wall between the room and the outdoors, with rated fenestration.
• An energy-code form on the permit, because conditioning the space triggers a thermal-envelope review.

If any of the three is missing, the room is almost certainly a Florida room or a screen room wearing a window unit, not a conditioned sunroom.

What a window unit does and does not buy

Comfort

A portable or window unit cools the air, so the room is pleasant. That is a lifestyle win and a legitimate reason to add one.

Code status

Bolt-on cooling does not make the room a conditioned sunroom. Permanent conditioning by the home's system, through a properly isolated assembly, is what moves a room up the ladder.

Appraised area

Because the unit is not part of the permanent system, an appraiser following ANSI Z765 still excludes the room from gross living area.

The energy-code trade you take on

Once a room is conditioned and tied to the house, the wall and glass separating it from the rest of the home — or the building, if it is Category IV — must meet the thermal envelope requirements of the Florida Building Code, Energy Conservation. Florida sits in Climate Zones 1 and 2, so the fenestration has to hit a U-factor and a solar-heat-gain target rather than being any glass that keeps the rain out. That is the cost of admission to Category IV-V, and it is a code cost, not a style choice.

Is a Lanai the Same as a Sunroom?

A lanai is not the same as a sunroom; a screened lanai is a Category I screen room. Lanai is a Hawaiian word for a roofed, open-sided porch that Florida adopted for its screened outdoor living rooms. It almost always has a solid roof and hard flooring, and it is usually screened rather than glazed — which lands it squarely at the bottom rung of the AAMA/NSA 2100 ladder.

The distinction matters because homeowners frequently want to "convert the lanai into a sunroom," and that phrase hides a category jump. Going from a screened lanai (Category I) to a conditioned sunroom (Category IV-V) means new glass, an insulated and isolated wall assembly, and an energy-code review — a full sunroom build or conversion, not a screen swap.

Lanai, porch, and Florida room sorted

• Screened lanai. Roofed, screened outdoor living room. Category I, unconditioned, non-habitable.
• Open porch or veranda. Roofed but open-sided, often along the front of the house. Not a sunroom category at all.
• Florida room. Glass-enclosed former porch, typically unheated. Category II or III, three-season.
• Conditioned sunroom. Glazed, insulated, and climate-controlled. Category IV or V.

The takeaway is that a lanai is an outdoor room you can use most of the year because Florida is warm, not because it is conditioned — and that is the right expectation to bring to a quote.

Which Enclosure Adds Square Footage

Only a conditioned sunroom adds to a home's appraised square footage; a screen room and an unheated Florida room do not. Appraisers in Florida follow ANSI Z765, the standard now used across most lending, and it counts only finished space that is permanently heated and cooled and has a ceiling at least 7 feet high as gross living area.

That rule is unforgiving on enclosures. A screened lanai has no walls or conditioning, so it is excluded. A Florida room with a window unit is conditioned only by a portable appliance, so it is excluded too. A Category IV-V sunroom heated and cooled by the home's permanent system clears the bar and is added to the GLA.

How the excluded rooms still carry value

Excluded does not mean worthless. An appraiser assigns a screen room or three-season Florida room a separate contributory value — it is reported and valued on its own line, outside the GLA figure. So the enclosures still help the home; they simply are not folded into the headline square footage that drives price-per-square-foot comparisons.

If your goal is a higher appraised square footage rather than just more usable space, the decision tree collapses to one rung: build to Category IV-V or accept contributory value only. That is also where a permitted, conditioned space starts to resemble a true home addition in scope.

Which Is Better for You

There is no universally better enclosure — the right one is the lowest category that meets your goal, because each step up adds construction and code obligations. Match the category to what you actually want from the room: bug-free evenings, year-round use, or a larger, more valuable house.

1. 1

   Choose a screen room (Category I)

   You want shaded, insect-free outdoor living and you accept that the space follows the weather. Lowest cost, simplest permit, no energy-code wall. Ideal over a pool deck or off the back slider as a screened lanai.

2. 2

   Choose a Florida room (Category II-III)

   You want glass to keep out wind, rain, and pollen and to use the room three seasons without committing to full conditioning. A practical middle rung that still will not add to gross living area.

3. 3

   Choose a conditioned sunroom (Category IV-V)

   You want a true year-round room that the appraiser counts as living area. This is the only path that raises gross living area, and it carries the FBC energy-envelope and, in coastal zones, impact-glazing requirements.

Read the list as a budget-and-goal filter rather than a quality ranking: a screen room is not a lesser sunroom, it is a different product solving a different problem.

How flooring choice tracks the category

The category even decides the floor. A Category I or II-III room swings with outdoor humidity, so it wants a dimensionally stable, moisture-indifferent surface — porcelain is the default, which is why we point lanai and Florida-room clients to tile flooring built for those swings. A conditioned Category IV-V sunroom holds steady indoor humidity, so it can take the same floors as the rest of the house.

Florida Code Realities

Three Florida-specific facts decide whether your project goes the way you expect, and all three flow from the category. They are the reason a sunroom in Florida is a permitted structure, not a weekend screen kit.

The HVHZ glazing rule

In the HVHZ — Miami-Dade and Broward — and across the wider wind-borne-debris region, any glass in a Florida room or sunroom must be product-approved impact glazing carrying a NOA or Florida Product Approval. A screen room sidesteps the glazing rule but still needs an engineered, approved frame to take wind load. We break the glazing side down in our HVHZ sunroom glazing guide.

The permit follows the category

Because the Florida Building Code treats Categories I-III as non-habitable and IV-V differently, the permit, inspections, and energy forms scale with the rung you choose. A deeper walkthrough of all five rungs lives in our AAMA category guide, but the headline is that you cannot quietly upgrade a Florida room to a sunroom without re-permitting.

Slab, drainage, and the existing structure

Most Florida enclosures sit on a slab-on-grade or an existing screened-porch slab, and that slab has to be sound, drained away from the house, and flat enough for the chosen floor. An enclosure built over a cracked or ponding slab will telegraph those problems into the finished room no matter how good the glass is — the foundation is the one variable the category ladder does not capture.