All You Should Know About Sunrooms

Sunrooms, four-season rooms and greenhouses are walled in glass and covered with glass or polycarbonate (a rigid, transparent thermoplastic).

The glass roof is quite expensive but provides the greatest transparency. Look for the U value of glass or polycarbonate; this is a measure of how much heat the material conducts. The lower this value, the less heat passes, so choose the lowest possible U value for the most energy-efficient room.


Glass walls must be silicone double-sealed, have A-level and be labelled “tempered safety” according to building codes. The best choice is as follows:

  • Glass with double glazing. This material ensures durability, insulation and reduced glare. Typical U values range from 2 to 2.5. Conventional glazing, in order of greatest or least efficiency, includes transparent, sun bronze and opal. Used for patio covers in Sacramento and Detroit most of all.
  • Double-glazed and low radiation coated glass. The application of a “low-emission” coating helps the glass to reflect heat and UV rays. The coating reduces the U value to about 1.7, thereby improving energy efficiency.
  • Double glass with argon filling and low-emission coating. Argon (inert gas) can be added to further reduce the U value to approx. 1.48.

For polycarbonate components, look for these options:

  • 6 mm double wall polycarbonate. Probably the most popular winter garden roof glazing option available today, this material has a U value of 2.3.
  • 20- and 25-millimetre double-walled polycarbonate. For a stronger roof, which also better insulates, this thickness is a good choice for creating a real “space for all seasons”. Typical U value is 1.6.
  • A porch with a flower seat and a napkin mat.

Heating and Cooling Sunroom Ideas

This material taken from If you can’t place your sunroom in the best place to control excessive loss or heat gain, or you just want to extend the hours that you can comfortably stay in your all-season room, consider these options:

  • Add a quick skylight to make it work as a heat sink when the room gets too warm.
  • Intersperse prefabricated roof insulation panels among the glass roof panels. Look for R-factors R-16, R-24 or R-32 (the higher the number, the better the insulation quality).
  • Build the walls in such a way that multiple windows can be opened. Select those that will work together to ensure optimal airflow.
  • Install ceiling fans to facilitate air circulation. Choose models with forward and reverse speed for summer or winter use.
  • Install outside shade tracks on the roof that hold the rigid outside sunscreens.
  • Select the window treatments that can be raised and lowered completely along with the most problematic areas of the wall.
  • Install a small gas heater in the room that you will use most often during cold months. For a more luxurious touch, install a radiant floor heater.
  • Farmhouse living room unpainted wood many windows

Average sunroom costs

This information is from the site of the LGL Sunrooms company. Below is the cost estimate for the 15-foot by 15-foot number:

  • Sunrooms in wood and standard materials start at $20,000. High-end aluminum and glass sunrooms cost $25,000. Of course, prices will vary depending on the design, materials, your region and the amount of work you will do yourself.
  • The cost of building four-season rooms will also vary depending on the heating and cooling requirements, as well as the details of the finishes. It is expected that you will pay at least $25,000 for the finished room.
  • Shielded verandas are a convenient option for a much lower price. You can get the desired result for $6,000 – $10,000.