Sunroom Sizes: What’s the Best for My Home?

Size up your options before you start sunbathing

A small breakfast table in a sunroom
Photo: Janine Lamontagne / E+ / Getty Images
A small breakfast table in a sunroom
Photo: Janine Lamontagne / E+ / Getty Images
Highlights
  • The standard sunroom size is 12 feet by 14 feet, or 168 square feet.

  • Size your sunroom based on your yard size and your intended use.

  • Most sunrooms are rectangular or square, but hexagonal is also popular.

  • Have a pro help you choose the dimensions to ensure you get it right.

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Investing in a sunroom is a great way to add some living space and luxurious utility to your home, but when it comes to sunroom size, it’s easy to get lost in the dimensions. In this guide, we’ll explain what the standard sunroom size is, how to choose what size is right for your property, and what to do if you find that a previously installed sunroom isn’t cutting it.

What Is the Standard Sunroom Size?

The standard sunroom is 12 feet by 14 feet, giving it a total interior area of 168 square feet. It’s not uncommon to see sunrooms as small as 8 feet by 10 feet or as large as 20 feet by 20 feet, but it depends on the size of the home it’s attached to and the size of the yard it’s in. Most sunrooms are rectangular or square, but hexagonal and octagonal sunrooms are popular, too.

Sunroom Dimensions by General Size

Sunroom builders will use specific dimensions to plan out your sunroom build, but for most homeowners, it’s easier to refer to sunrooms by general sizes: small, medium, and large.

Small
8x1080
8x1296
10x10100
10x12120
Medium
12x12144
12x14168
12x16192
14x14196
Large
14x16224
16x20320
20x20400

Small Sunroom Dimensions

Small sunrooms are those that are 125 square feet or smaller. For a rectangular sunroom, which is most common, that would be a maximum of 10 feet by 12 feet. A small square sunroom would be 10 feet by 10 feet. For hexagonal or octagonal sunrooms, which are more common shapes for solariums and conservatories, you’re looking at 12 feet by 12 feet in both dimensions, giving you a total area of 124 square feet.

Medium Sunroom Dimensions

Medium sunrooms can fit dining furniture to create an outdoor dining space or additional seating over a small sunroom. The versatility of a medium sunroom size makes it the most popular. Medium sunrooms fall between 125 square feet and 200 square feet.

The most common size for a medium rectangular sunroom is 12 feet by 14 feet, which would be 168 interior square feet. For a medium square sunroom, you can go as large as 14 feet by 14 feet. For hexagonal and octagonal sunrooms, a medium size would be anything larger than 12 feet in both dimensions. In this case, 14 feet by 14 feet is standard and would provide 170 square feet inside for a hexagonal sunroom and around 140 square feet for an octagonal sunroom.

Large Sunroom Dimensions

Large sunrooms are those that are larger than 200 square feet. These sizes can fit large dining tables and may be able to accommodate additional seating areas and entertaining spaces, as well. Large sunrooms can look out of place in smaller yards or when attached to small main structures, so consult with a sunroom contractor before going this route.

A large rectangular sunroom will have minimum dimensions of 14 feet by 16 feet, and it’s uncommon for them to get much larger than 16 feet by 20 feet. For a square sunroom, 20 feet by 20 feet is about the biggest you’ll see in most cases. For hexagonal or octagonal designs, you’ll rarely see sunrooms with lengths and widths larger than 20 feet. For a hexagonal sunroom, that would mean close to 350 square feet, and these dimensions would be closer to 300 square feet for an octagonal sunroom.

How to Calculate the Right Size Sunroom

Interior view of a white PVC conservatory extension
Photo: John Keeble / Moment / Getty Images

The best way to calculate the right size for your sunroom is to consider how you want to use the space and then take space constraints into consideration.

  • Seating and relaxation: If you’re just looking for a small space to keep some plants and have seating to enjoy the sun without the bugs, you can go with a small sunroom that’s 8 feet by 10 feet. This is about twice the size of a standard full bathroom for reference.

  • Casual dining: A medium sunroom is best if you want to fit a dining table and chairs inside, so go with 12 feet by 14 feet or 12 feet by 16 feet, which is about the size of a large bedroom. This will give you enough room for a dining set that seats six, plus room to maneuver while people are seated.

  • Entertaining: Hosting dinner parties or even casual dining for larger families will demand a large sunroom. Aim for 16 feet by 20 feet for a dining set that seats eight to ten. Upsize to 20 feet by 20 feet if you also want to place couches or additional seating aside from the dining set.

Factors That Influence Sunroom Size

Modern conservatory interior
Photo: DGLimages / iStock / Getty Images Plus / Getty Images

Choosing a sunroom size that works for your intended purpose is fairly straightforward, but there are some things you should think about aside from what dimensions would be ideal.

Yard Size and Utility

Your sunroom will take up space in your yard, so you should consider how the dimensions you choose will affect your property’s usability. You might need to consider downgrading your sunroom size if you have a smaller property and still want ample outdoor space.

Property Lines

Your local municipality has rules and regulations about how far from your property lines you can build. Average setbacks include a minimum of five feet from the sides of the property and 10 to 20 feet from the rear property line. A reputable sunroom contractor near you will pull sunroom permits and ensure your structure is up to code, but make sure you consider these constraints when planning out your sunroom build.

Cost

Sunrooms cost between $150 and $300 per square foot, so increasing the dimensions can very quickly inflate your total price. The cost depends on the type of sunroom you’re building, the quality of materials, your location, and more, so speak with a professional to get an accurate estimate. You can use the average costs below to get a rough estimate, though.

Dimensions (Ft.)Cost Range
8x10$12,000–$24,000
8x12$14,400–$28,800
10x12$18,000–$36,000
12x12$21,600–$43,200
12x14$25,200–$50,400
12x16$28,800–$57,600
14x16$33,600–$67,200
16x20$48,000–$96,000
20x20$60,000–$120,000

House Size

You should take the size of your house into consideration, too. Installing a large, 400-square-foot  sunroom on a 1,000-square-foot house will look strange, while a small 80-square-foot sunroom will look out of place or like an afterthought on a larger home with a massive footprint. Sunrooms add value to your home in most cases, but they could detract from value if they’re improperly sized.

What to Do If You Have the Wrong Size Sunroom

Unfortunately, changing the size of a sunroom is very expensive and disruptive, so your best option may be to knock down the existing structure and have a local sunroom contractor build a new one. Since a Florida room addition will cost an average of $47,000, you may just want to make the most of what you have.

For a sunroom that’s too small, you could have a pro who builds sunrooms install French doors on one side leading out to a patio area, which could give you room to sit inside while keeping the dining option entirely outside. For a sunroom that feels too large, you can use furniture to partition off the area inside. Set up a dining space on one side and a sectional with a coffee table on the other. Add plants and decor to take up space and make the sunroom feel cozier.

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