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How To Build A Four Season Sunroom On A Deck

Turning your deck into an all-season sunroom might be one of the best upgrades you can do to your home. It will let you enjoy that extra new enclosed space no matter the time of the year. If you're wondering how to make this possible, we have researched the project, and this is the answer we found:

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To build a four-season sunroom on your deck, you need to go through four stages:

  1. Planning
  2. Designing
  3. Building
  4. Furnishing

Those stages include a lot of things which we will discuss one by one to help you build your very own sunroom. If you're also looking for design inspiration that you can adapt to make your space homier, we'll cover that, too! We have a lot to talk about so let's get going!

New modern screened porch with patio furniture, How To Build A Four Season Sunroom On A Deck

Building A Four-Season Sunroom On A Deck

New modern screened porch with patio furniture, summertime woods in the background. New home addition concept.

Decks are a great area for your home. However, the time when you can use it is limited due to changes in season. Its open-space feature makes it perfect for the summer, but it isn't an ideal spot to gather when it rains or during the winter.

If you are only building a sunroom to enclose your deck, we will cover the reasons why you should pursue this. First, it lets the natural light (sunlight and moonlight) in. Did you know that natural light has a lot of benefits for your well-being and your home

Take a look at the benefits we are talking about:

Second, it adds functionality to your home. This room can serve as your new gathering area. Since the sunroom has a unique vibe from the rest of the rooms in your house, it is a good spot to hold gatherings.

Third, the glass windows, walls, and roof let you experience the ambiance of what is outside while staying indoors. Plus, it is an all-purpose sanctuary. Depending on the features you will add inside, it might be the new favorite part of your house!

Yup, we know you're going to do it. Here is the first step you need to take to build a sunroom on your deck. 

Stage 1: Planning

In this step, you will need to determine if your house can accommodate the new sunroom. Sunrooms can be built on three kinds of foundations—preexisting deck, concrete slab, and crawl space.

In this article, we will talk about how you can check your preexisting deck's capability to support a sunroom. Here are the points you need to check to ensure that you have the best foundation:

  • What is the condition of your deck's foundation?
  • How is your deck attached to your house?
  • What is your deck made of?

Checking Your Deck's Foundation

To build a good base, examine if the deck's foundation is sturdy enough to support the sunroom's structure. It should be in a good, sturdy condition—not old or damaged.

Decks can last from 10 to 30 years depending on the material used. If its age is already in the scope of its life expectancy, consider getting repairs or upgrades. 

In addition to this, analyze if the deck's foundation is leveled. You don't want the surface to be slanted or uneven. 

How Is Your Deck Attached To Your Home?

Knowing how your deck is attached to your home can help you determine what design you can consider for your sunroom. Moreover, you will know if the fasteners (hidden or not) are still clasped securely.

If you are not sure what kind of deck attachment you have, here are some of the most common kinds of decks:

  • Attached deck: looks like an extension of a room outdoors since it has a single door that connects it to the inside of the house. 
  • Detached deck: separated from the structure of the home and standing on its own. 
  • Wraparound deck: an upgraded version of the attached kind since it extends to the sides of the house. 

What Is Your Deck Made Of?

A variety of materials is used by builders to construct a deck. Figure out what yours is made of. This can let you assess if your foundation is strong and build-ready.

Since the materials have dissimilar compositions, they have differing symptoms of aging which you will need to address later on. 

Below are some of the materials commonly used for decks and the issues they may already have. Check out which one is yours. 

  • Wood - Can rot, prone to molds, sagging, and bending.
  • Composite - Prone to Scratching and color fading.

If you are not sure about determining any of these points, you can ask for a professional to assist you. 

Want to get rid of annoying footprints on deck? Learn how here: Footprints On Stained Deck; How To Prevent And Fix

Stage 2: Designing

After analyzing your deck's type (attached, detached, wraparound, etc.), it will be easier to sketch the design you want. Take a look at the parts of your sunroom that you will need to design and pay attention to:

  • Roof
  • Color palette
  • Door type
  • Windows
  • Skylight
  • Theme
  • Furniture
  • Lights

You can add personal touches and add your favorite style here. If you are hiring a contractor and architect, it will help them if you can envision the finish that you want for your sunroom.

Stage 3: Building

After finalizing the design, you will now proceed to build. There are sunroom kits available, but it's safer if you let a professional builder do the job. 

Remember, safety comes first. It is better to be sure that your sunroom will be built in the best way possible by those who are experts in the field. However, we cover the process of building your sunroom below. 

  • Get rid of any unneeded parts of the deck.
  • Install the bottom plate
  • Frame the walls.
  • Set up the exterior sheeting. 
  • Install the doors, windows, and exterior trim and siding.
  • Add insulation. 
  • Furnish the space.

Step 4: Furnishing

The last step of building your sunroom is adding the finishing touches. Here, you can incorporate the styles you want to put in the space. If you're unsure about this step, we will provide you with inspiring design ideas that other homeowners have tried. 

Starting with a simple one, this four-season sunroom is designed in a minimalist way. The colors and materials of the furniture blend well with the woods outside. 

What's better than eating in an open area? This dining room has a warm and cozy feeling. Meanwhile, the designers set the focal point towards the chandelier, adding an elegant touch.

Attuned to nature, this design is filled with plants and a cozy sofa. This kind of setup is relaxing and inviting at the same time. 

What Is A Good Size For A-Four Season Sunroom?

The best size for a four season sunroom depends on how you will use the space and the furniture and decor you will put in it. Small sunrooms can be converted to a reading nook, coffee table spot, or a small playroom. 

On the other hand, large sunrooms are perfect for recreations, home theater, dining, or a garden. 

What's The Cost Of Building A Four-Season Sunroom?

Four Seasons Sun Room With Wicker Furniture and Outdoor View

A four-season sunroom may cost $25,000 to $80,000. The price varies on the complexity of the structure. If you hire a professional installer, you will most likely pay an additional $5,000 to $20,000.

Want additional information on this topic? Read more here: How Much Does A Sunroom Cost?

How Long To Build Four Season Sunroom On A Deck?

The typical duration for building a sunroom ranges from 2 to 4 weeks. This will vary on the following factors and how long they will take to be done. 

  • Contractor's availability: companies who provide this service are often busy around the spring and fall seasons.
  • Site preparation: 1 to 2 days (if a deck's foundation is sturdy), more than 2 days (if the foundation needs solidifying).
  • Deck building: 3 to 4 days. 
  • Installation of walls and roof: 4 to 6 days.
  • Finishing touches: 2 days.
  • Weather: can cause delay. 

Is A Four-Season Sunroom Worth It?

Sunroom with a wicker hammock and tall windows in the background.

Yes, a four-season sunroom can offer you a lot of benefits. It also provides good insulation against outside temperatures.

Another benefit is that it increases a home's value because of the functionality that is added to your house. Some of the most popular conversions are the following:

  • Master suite
  • Recreation room
  • Home office
  • Breakfast room
  • Fitness room

Final Thoughts

Building a four-season sunroom on a deck includes four stages—planning, designing, building, and furnishing. If building is not a part of your expertise, it is best to hire a contractor.

The contractor will assess your deck's foundation, assist you with the designing, and then build your sunroom properly. This is a very good investment, since adding a four-season sunroom van adds value to your house.