Lanai vs screened porch vs sunroom in Florida

In Florida, “lanai” and “screened porch” usually mean the same thing: a roofed outdoor room at the back of the house with screen walls. A sunroom has glass or vinyl panels and may be air conditioned. The building code doesn’t care which name you use. It sorts all three into five sunroom categories based on what the walls are made of and whether the room is heated or cooled. Choose the category first, because it decides the price, the permit and whether the room counts as living space.

If you’re building a screen cage over a pool rather than a room off the house, read the pool screen enclosure guide instead.

How Florida’s code sorts these rooms

The Florida Building Code, Residential, says sunrooms must comply with the AAMA/NPEA/NSA 2100 standard and groups them into five categories. A Florida Building Commission staff analysis quotes the definitions from the 2017 edition:

Category	Walls	Heated or cooled?	Habitable?	What most people call it
I	Open or insect screening	No	No	Screened lanai or porch
II	Glass or plastic panels	No	No	Vinyl or glass three-season room
III	Enclosed, with windows that meet extra air-infiltration rules	No	No	Tighter three-season room
IV	Enclosed	Yes, by its own separate system	No	Air-conditioned sunroom kept separate from the house
V	Enclosed, open to the main house	Yes	Yes	Florida room or true addition

Two things follow from that table. First, a screened lanai and a glass room with no AC are in the same family. Neither counts as habitable space, so they can be built lighter than an addition. Second, adding air conditioning changes the category. The same staff analysis notes that outlet requirements differ too: under AAMA 2100, Categories I to III are exempt from the receptacle-outlet rules that apply to Categories IV and V. Category numbering and wording can change between code editions, so ask your designer which edition and category the plans use.

Screened lanai or porch (Category I)

This is the classic Florida setup: a concrete slab under a roof, either an extension of the house roof or an aluminum patio cover, with aluminum framing and screen walls. It’s the cheapest way to get a room you can use in summer without mosquitoes, and the breeze still comes through. Its downsides: summer humidity and heat come in with the breeze, rain blows in sideways during afternoon storms, and the furniture has to be outdoor-rated.

Costs depend on what you’re starting from. Fixr’s figures are:

• $5 to $7 per sq ft to screen in an existing covered patio
• About $20 to $25 per sq ft for a patio screen enclosure
• $30 to $47 per sq ft for a new covered, screened patio, depending on material and cover

A Central Florida builder quotes basic patio or porch enclosures at $6,000 to $10,000, or $10 to $24 per sq ft. If the patio has no roof yet, the roof is the big decision. Fixr prices aluminum patio roofs at $20 to $70 per sq ft and insulated roof panels at $26 to $59 per sq ft. Insulated panels are worth considering when the room is right outside a living room, because they keep the ceiling from radiating heat.

Glass or vinyl room without AC (Categories II and III)

Replacing screens with vinyl or glass panels keeps out rain, pollen and wind, so you can use the room on a stormy afternoon or a cool January evening. In July, though, an unconditioned glass room facing south or west can be hotter than outdoors. Open windows or ceiling fans help, but most owners end up wishing they’d planned for AC.

Fixr prices a glass-enclosed patio at $30 to $95 per sq ft, with most around $65. Its sunroom guide puts three-season rooms at $20,000 to $50,000. That guide was last updated in November 2022, so treat its figures as a floor and get current local quotes.

The difference between II and III is mostly the windows. Category III windows must meet extra air-infiltration requirements. If you think you’ll add a small AC unit later, ask what it would take to meet the Category IV rules now, while the walls are being built.

Air-conditioned sunroom (Categories IV and V)

A conditioned sunroom is the only option that’s comfortable in August with the doors closed. Category IV has its own temperature control and stays thermally separated from the house, for example with an exterior door between them. Category V opens to the house and is treated as habitable, conditioned space. In practice it’s a room addition, and it has to meet the energy and egress rules that apply to any room of the house.

This is the expensive end. Fixr’s national figures put four-season rooms at $35,000 to $100,000, with an average around $55,000 for a 14x14 ft room. Additions run $130 to $300 per sq ft, and converting a three-season room to four-season costs $5,000 to $20,000. Fixr also notes that a sunroom can raise your property tax, though probably not by much. Again, these figures are from 2022.

Glass choice matters more in Florida than almost anywhere. Fixr prices low-E glass at $5 to $35 per sq ft installed and double-pane glass at $10 to $20, against $3 to $8 for single pane. In a room that gets afternoon sun, better glass is what makes the AC able to keep up.

Permits: what Tampa Bay asks for

All of these need a permit in Hillsborough County. Its screen enclosure and glass room checklist covers sunrooms, lanais, vinyl windbreaks and similar projects under a Residential Miscellaneous Permit. It asks for:

• A to-scale site plan showing setbacks, easements and a tree statement
• Plans designed to the current Florida Building Code, signed and sealed by a Florida-registered architect or engineer
• A recorded Notice of Commencement before the first inspection
• A category from I to V marked on the plans
• A floor plan showing adjacent rooms and egress windows, where applicable
• If mechanical equipment is retrofitted, energy forms (R402 or R405) and a Manual J load calculation from a mechanical contractor

The egress item catches people out. If the new room closes in a bedroom window that was an emergency exit, the plans have to show how that bedroom still meets egress rules. Homes in a Special Flood Hazard Area also have flood rules to meet. Fixr puts a typical building permit at $400 to $600 with 4 to 8 weeks for approval, but fees and timing vary by jurisdiction. Cities such as Tampa and the other counties run their own building departments, so confirm with yours.

Which one fits your house

• You mainly want to sit outside without bugs: a screened lanai (Category I). Spend the extra on a good roof and ceiling fans rather than glass.
• You want to use it in rain and wind, but not all summer: vinyl or glass panels (Category II or III). Put it on the north or east side if you can.
• You want a real room you’ll use every day: Category IV or V, designed for AC from the start. If it’s going to be a Category V Florida room, budget for it like an addition.

For shade-only options like pergolas, sails and solid patio roofs, see pergola vs shade sail vs screened lanai. Price ranges for screen enclosures by city are on the pool enclosure cost page.

What to ask before you sign

1. Which sunroom category are you designing this as, and under which edition of the Florida Building Code?
2. If I want to add air conditioning later, what would have to change: walls, windows, electrical, permit?
3. Does the new room cover a bedroom window, and how do the plans handle egress?
4. What roof are you quoting (attached, aluminum, insulated panel), and what wind speed is it engineered for?
5. Are signed and sealed plans, permit fees and inspections included?
6. What screen mesh or glass is in the quote, and what does replacing one panel cost?
7. Who handles the electrical and any AC work, and are they licensed for it?
8. What is your Florida license number? Look it up yourself at myfloridalicense.com and ask for a current certificate of insurance. Backyardly doesn’t check licenses for you.

See it in your own yard first

A screened room, a glass room and a conditioned addition all change how the back of the house looks. An AI concept made from a photo of your own house helps you compare roof lines and wall styles before you ask for quotes, and gives local pros a clear picture of what you want.