A Guide to Sunroom Construction and Building on a Budget

For homeowners looking to create additional living space, sunrooms are an appealing option, one that allows for bridging the gap between indoors and out while also extending the footprint of your residence. This type of project, however, can quickly become pricey. Since sunrooms are essentially an extension of your home, they require many of the same building materials as any other type of significant home addition.

Here's a closer look at what to expect when embarking on a sunroom project and how to cut costs if you're on a tight budget.

Lauren Krysti

What is the average price of sunrooms?

Like nearly any other type of construction project, the cost of building a sunroom varies significantly based on the size and type of sunroom structure you're planning, the finishes selected, and whether you opt for a custom design or a prefabricated kit.

In general, standard sunroom construction costs about $120 per square foot and a high-end sunroom construction will be about $300 per square foot, says David Steckel, a home expert with the San Francisco, California-based home services website Thumbtack.

Three-Season vs. Four-Season Sunrooms

Another key factor impacting the overall price tag of your sunroom is its intended final use. In other words, are you hoping to create a room that can be enjoyed for three seasons a year or four? A room designed to be utilized all year long, even when the weather gets much colder (or hotter), will be far more expensive to build.

"Four-season rooms are typically wired for electricity, have HVAC installed, and may even have plumbing," explains Steckel.

A standard three-season sunroom (meaning a room that's not insulated) can cost anywhere from $15,000 and $40,000, says Andrew Johnson, home remodeler and founder of Prime Seamless in San Antonio, Texas.

"On the other hand, a four-season sunroom that's fully insulated and most likely includes amenities like electricity, plumbing, and HVAC…will cost you between $25,000 and $80,000, depending on your customizations," says Johnson.

Those who are hoping to build a sunroom on a limited budget might want to steer clear of more luxurious four-season rooms.

Prefabricated vs. Custom-Built Sunrooms

Yet another way to reduce the budget for your sunroom is to opt for a prefabricated kit rather than a new custom sunroom that is built on site. Prefab sunrooms can be put together more quickly and efficiently compared to ground-up construction.

"When purchasing a prefabricated sunroom, materials dictate cost with aluminum being the least expensive, vinyl the mid-level option, and wood-framed sunrooms the most expensive," says Steckel. "Other factors that affect the cost of prefabricated sunrooms include window type (double-pane versus insulated), whether the sunroom is wired for electricity or HVAC, and whether it has simple glass walls that enclose a porch space or something more elaborate."

Prefab sunrooms can cost anywhere from $6,000 to $30,000 or more, not including installation, says Steckel.

Karin Lidbeck Brent

Sunroom Siding, Flooring, Window Styles, and Roof Materials

Building a sunroom requires making decisions about a variety of materials that will be part of the final look of the space, including roof type, flooring, siding, and window style, says home builder Richard Lee of Texas-based Lee Brothers Construction.

"These all play a role in the functionality and price," explains Lee. The most common types of flooring used in sunrooms, for instance, are vinyl plank and tile. It's possible to use other types of flooring, such as stained concrete and wood, but most homeowners prefer the tile look, says Lee.

"In terms of pricing, from least expensive to most expensive, it looks like this: tile, vinyl plank, stained concrete, and finally wood as the most costly," says Lee. "Tile and vinyl plank are very similar in price at $6 to $7 per square foot installed, while stained concrete and wood can cost as much as 50% more due to custom finishes."

Siding is another consideration that impacts the final price of your project. "Pricing can vary greatly due to the wide range of options. Hardie and LP siding cost more than vinyl siding. Brick and stone cost more as well," explains Lee.

Vinyl, the least expensive siding option, is about $8 per square foot installed. Hardie and LP SmartSide siding ranges from $12 to $15 per square foot installed, while brick and stone will be the highest cost alternative, and homeowners can expect to pay approximately $25 to $30 per square foot.

"Each of these figures is based on remodeling costs, which includes demo of existing and installation of new siding," says Lee.

Finally, depending on where you live and how much of the year you hope to use your sunroom, air conditioning installation might also be part of the overall costs, which will be far more expensive than simply adding ceiling fans to the space. This is because a licensed HVAC installer is required for air conditioning installation in order to extend your home's air conditioning ducting or to add a mini-split HVAC unit for the sunroom, says Lee.

Must-Know Sunroom Building Tips

When it comes to successfully pulling off a sunroom construction project, it's crucial that homeowners spend plenty of time in the research and planning phase as well as building their team of professionals. Don't skimp on these steps.

As part of your initial efforts, Steckel recommends researching images and ideas for your finished sunroom so that you have a clear picture of what you're aiming to build, and you can share the imagery and vision with whomever you hire to bring the project to fruition.

"I recommend compiling at least 20 inspiration images and putting them into a folder or saving them on a Pinterest board," explains Steckel. "This will be helpful in the long run as it will help the renovation team organically determine your aesthetic expectations, and also help them anticipate additional costs for your scope of work."

Always be sure to share your vision with the renovation team to ensure they understand your expectations at the outset, allowing you to avoid unexpected costs in the middle of a project. Collecting imagery that supports your aesthetic and overall vision is just one part of getting your project successfully off the ground.

"The number one mistake that homeowners make is rushing to begin their job," adds Steckel. "Every day that you spend planning, hiring your team, selecting finishes, and value engineering takes days if not weeks off the duration of the job," says Steckel. "Doing this well is the only way to accurately price your job and it is the only way to make sure there are no surprises."