Four Season Room Builders in Austin, TX: Cost, Construction and What to Expect

What is a four season room?

A four season room, also called a four season sunroom or an all season room, is an enclosed room attached to your house that you can use year round. The defining features are insulation in the walls and roof, dual-pane low-E glass instead of single-pane or vinyl sliders, and a heating and cooling source, which in the Austin area is usually a ductless mini-split. The result is the closest thing to a conventional room addition: as comfortable as your living room in August and in a January freeze.

That is what separates it from the other two kinds of enclosed porch we build. A screened porch is a roof with screen walls, so the temperature is whatever it is outside. A three season room swaps the screens for sliding vinyl windows over knee walls, usually with a ceiling fan, and keeps out rain, dust, pollen and bugs, but it is not insulated or conditioned, so it gets hot closed up in midsummer, especially facing west. A four season room is the only one of the three that is genuinely a room of the house.

How much does a four season room cost in Austin?

In our pricing, a four season insulated sunroom runs about $200 to $350 per square foot installed. A 14x16 room, which is 224 square feet, typically lands between $55,000 and $90,000. That covers the structure, insulation, dual-pane low-E glass, the electrical for lights, fans and the mini-split circuit, the roof tie-in to your house, finish trim, and the permit and energy code work.

For comparison, a three season room with sliding vinyl windows runs about $120 to $220 per square foot, or $30,000 to $48,000 for a 12x14 room. Screening in an existing 12x16 covered patio runs $8,000 to $14,000, and a new 14x16 screened porch with its own roof runs $22,000 to $35,000. The jump from three season to four season pays for insulation, better glass, conditioning and the energy code review that comes with a conditioned space.

What moves the number inside that range: size, how the roof ties into your existing roofline, how much glass versus insulated wall you want, whether the room sits on an existing slab that can carry it or needs new footings, the window brand and glass package, and the electrical scope. We quote all of it as one fixed written price, so the figure you sign is the figure you pay.

Three season room or four season room: which should you build?

Start with how you will use the space. If the goal is bug-free evenings from spring through fall and rain protection, a screened porch or a three season room does the job for a lot less money, and with the windows open a three season room behaves like a screened porch. If you want a breakfast room, a home office, a place for the grandparents to sit in July, or square footage that reads as living space when you sell, you want a four season room.

Exposure matters too. A west-facing three season room closed up in August will be an oven. A four season room with insulated glass and a mini-split on the same wall stays comfortable. We look at your sun exposure during the consultation and tell you honestly which room fits your budget and how you will actually live in it.

Plenty of our clients start with a screened porch or three season room and plan to upgrade later. If that is the plan, say so at the design stage. The posts, beams, footings and roof connection can be built from day one to carry insulated walls and windows later, which is far cheaper than reinforcing the structure after the fact.

How is a four season room built?

We frame four season rooms on site as structural additions. The sequence is foundation or structural prep first, then wall and roof framing, the roof tie-in and flashing where the new roof meets your house, electrical rough-in, insulation, windows and doors, and finally finish trim inside and out. The same crew that starts the room finishes it, with daily cleanup and a clear picture of what is happening each day.

The roof connection is where most sunroom leaks start, so it gets the most attention. We tie the new roof into your existing roofline or wall, attach and flash the ledger properly, and match roofing, siding and trim so the finished room looks like it was always part of the house. This is the main difference from a bolt-together aluminum kit, which sits on the patio as an obvious add-on and rarely matches the architecture.

Timeline: permits typically take 2 to 6 weeks before construction begins, with conditioned rooms at the longer end because of energy code review. Construction on a sunroom typically runs 4 to 8 weeks depending on size, glazing and the conditioning work. You get a realistic schedule with your quote, and because the same crew stays on the job, the schedule we give is the one we keep.

Permits, energy code and HOA review for a four season room

Every enclosed room attached to a home needs a building permit in the cities we serve, from Austin to Round Rock, Cedar Park, Leander, Georgetown and Liberty Hill. A four season room also goes through energy code review, which means the insulation values and window specifications get checked before the permit is issued. That is one reason a four season room takes longer to permit than a screened porch.

Most HOAs in the Austin suburbs want architectural approval before the city permit, with a site plan, materials and colors. In the City of Austin, a room near a protected tree also gets tree review. We prepare and submit all of it, the HOA application, the city permit, the energy code documentation and the inspections, as part of every project. You sign where we tell you.

Can you convert an existing patio or three season room into a four season room?

Sometimes, and the answer comes down to the structure underneath. A covered patio was engineered to carry its own roof, not insulated walls, a window system, a door and the wind load that comes with enclosing the space. A three season room built light for sliding windows may or may not carry dual-pane glass and an insulated roof. We inspect the posts, beams, footings and slab before quoting, tell you exactly what can be reused and what needs reinforcement, and price the conversion against a new build so you can compare real numbers.

If the bones are good, a conversion keeps cost well below a from-scratch room. If they are not, we say so before construction, not after the first storm.

What to ask a four season room contractor

Ask how the roof ties into your house and how the flashing is detailed where the two meet. Ask whether they will check your existing slab or deck before quoting. Ask what glass, insulation values and window brand are in the quote, and whether the electrical for the mini-split is included. Ask who handles the permit, the energy code review and the HOA submission. And ask who will be in your yard every day and whether the same crew finishes the job.

Red flags: a price over the phone without a site visit, a large deposit before there is a design, a discount that expires tonight, a quote with no product names, and a plan to attach a heavy window system to a patio cover that was only built to hold up a roof. Texas does not license general home improvement contractors at the state level, so look at how long the company has been building in your area, read its Google reviews, and ask to see rooms it built several years ago.

How to get a four season room quote from All Seasons

All Seasons Decks and Gazebos was founded in 1984 by Peter Toomey, and Mark Toomey runs projects today from our shop in Liberty Hill. We build screened porches, three season rooms and four season rooms across Austin, Round Rock, Cedar Park, Leander, Georgetown, Pflugerville, Hutto, Lakeway, Bee Cave and Dripping Springs, with one crew from the first post hole to the final walkthrough, and a 1-year workmanship warranty in writing plus the manufacturer warranties on windows and materials.

We will come out for a free on-site consultation, look at your exposure and your existing structure, and deliver a fixed written quote within 24 hours of the visit. Call (512) 812-8168 or request a quote online.