Differences Between a Three and Four Season Sunroom

Differences Between a Three and Four Season Sunroom

If you have a sunroom, whether it is of the three or four season variety, you already know of their wonderful benefits. You have a space to entertain protected from rain, snow and heavy winds. You can feel close to nature without having to deal with pesky insects and other pests. You may use it for your favorite hobby, for meditating, for dining, for working from home: the possibilities are almost endless. But for those thinking about purchasing a new sunroom or even remodelling your space into a sunroom you may be trying to determine what type of sunroom will suit you and your family. 


The framing materials for three and four season sunrooms differ.

Three season sunrooms

These sunrooms usually are built using a light aluminum frame. 

Pros: Aluminum is strong, low maintenance and cost effective

Cons: Insulation is poor. Any heating and cooling (example: space heaters and window air conditioners) may not be very efficient since lack of insulation means some of the heating and cooling will escape to the outdoors.

Four season sunrooms

These sunrooms are generally built with thermally engineered aluminum or vinyl. It’s usually reinforced with steel or aluminum. 

Pros: Creates a strong frame, good insulation. Keeps heating and cooling very efficient since the insulation is good. 

Cons: Startup cost is greater.

Insulating Materials

Three season sunrooms usually come with some insulation in the walls, floors and ceilings. The basic difference between the insulation in three and four season sunrooms is in the amount and quality. A four season sunroom will have thicker and better quality insulation. This offers a more airtight environment that ensures more comfortable temperatures year round and the ability to use your sunroom for all seasons. 

Glass Materials

Both types of sunrooms highlight windows and doors. Many varied glass options are available for both sunroom types.

Three season sunrooms often are built using single pane glass but can be upgraded to double pane glass. 

Single Pane Glass

Pros: lower cost

Cons: Generally not UV protected. Often drafty, and can’t filter out as much outside noise. Won’t protect furniture or floor from fading from strong sunlight. Glare can also be a problem. Room can get uncomfortably hot when the sun is at its strongest in the summer

If a purchaser decides on single pane glass, it would probably be wise to add insulating drapes for colder weather or when the sun is at its hottest. Tinting single pane glass can also help to filter out radiation and heat. However, this can also darken the view to the outside. 

Double-Pane Glass

Double pane glass is standard with a four season sunroom. It helps to insulate the room and therefore improves heating and cooling. It is usually insulated in between the glass with Argon gas. Special coatings, such as UV coatings help to minimize solar heat loss and gain.

Pros: Minimizes heat loss and heat gain. Cuts out glare. Cuts down on furniture and floor fading. Contributes to making your HVAC system more efficient (keeping costs down).

Cons: Cost is substantially higher than single glass

Door and Window Tracking

Both types of sunrooms employ tracking that makes for easy operation. 

Three season sunrooms usually use a triple track system to open doors and windows while four season sunrooms often use a monorail system. Both types use ball bearing wheels to ensure ease of use.


If you have a three season sunroom, you’ll likely be able to employ portable heating and cooling items like floor and ceiling fans, portable heaters, and window air conditioners to cool down or take the chill off. However, heaters are unlikely to provide enough heat to make for a comfortable environment in the winter. 

In a four season sunroom, both heating and air conditioning may be connected to the HVAC of the main house. However, a ductless mini split system is also popular for a sunroom as there is no outlay of money for duct work. The cost for heating and cooling with a mini split system is usually cost effective as well.

Cost Difference

Because of the higher quality materials used in a four season sunroom and the planning involved, the cost can easily double (or more) that of a three season sunroom. The added insulation, dual pane treated glass, and structural engineering do add up. However, the comfort and enjoyment of being able to use your sunroom all year round may be worth it for you. A four season sunroom also legally adds to the square footage of your home and is likely a nice selling point. 

Deciding on a Sunroom Type

Deciding on a Sunroom Type

Only you can decide which type of sunroom is right for you and your family. If after researching you’re still scratching your head, ask yourself some important questions.

  • What do I plan to use the space for? 
  • How often do I plan to use the space?
  • What important features do I want?
  • What is my budget?

If you imagine a sunroom for more casual usage, say to mainly look out at beautiful blossoming trees and plants in the Spring, Summer and Fall, you may decide that a three season sunroom is quite adequate. And of course, budget concerns may also determine that a three season sunroom works best for you. 

However, for instance, if you plan to use your sunroom to work from home, you will require a comfortable temperature year round to be at your most productive. In this case, a four season sunroom would be wise. Likewise if you decide this would make a nice guest room, this also would suggest that an easily and efficiently heated/cooled room is quite important.

Whether you choose a three or four season sunroom, both offer many delights and advantages. Adding natural sunlight and extra room to your home will add to your relaxation and comfort for years to come.

Common Repairs for Sunrooms

Now that you have your sunroom built and are enjoying being there, you can relax knowing it has been built to the best standards. However, if you have an older sunroom or one that was not built so well, there may be problems that need repair. Even if your sunroom is brand new, it’s always wise to know what to look out for when it comes to common problems that may occur in the future and the repairs needed.

  • Water leak and roof repairs
  • Floor repairs
  • Shingle Replacement
  • Storm Damage repairs 
  • Hail damage repairs
  • Damaged Siding
  • Torn Screen replacement
  • Door and window replacement
  • Bent or cracked frame repairs
  • Electrical shorting and other problems
  • HVAC unit malfunction

Does Adding a Sunroom Increase Home Value?

After installing a sunroom, you can see that your home gets more attention than comparable homes without a sunroom. As the living space of your home increases you can make its overall value go up. Additionally a sunroom can provide more natural light into your home which also helps to save on energy costs. 

Sunshine Sunrooms has been helping homeowners design and build beautiful sunrooms since 1993. We offer individualized services based on each of our client’s specific budgets, vision and needs. Call us at (972) 243-5390 for all your sunroom design, construction, and repair needs or contact us online to request a quote.

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