On average, expect to pay between $150 and $300 per square foot for sunroom costs. A small 8-foot by 10-foot sunroom costs around $4,000 to $6,000, but a 12-foot by 20-foot sunroom might average around $20,000. The final cost will also depend on the type of sunroom you choose since an insulated sunroom will cost more than a simple atrium.

Most sunroom additions cost between $8,000 and $80,000. The average is just above $30,000. Expect to pay around $25 per square foot for uninsulated spaces and up to $300 per square foot for four-season structures. Prefabricated kits range between $5,000 and $30,000. Professional labor typically totals between $4,000 and $20,000.

The high cost is $100,000 for a custom-made four-season 12’ x 20’ sunroom addition with luxury windows and flooring.

On average, it costs between $150 and $300 per square foot to build a sunroom.

On average, a sunroom costs $150 to $300 per square foot to build. This includes site preparation and post-construction cleanup labor. As a general rule, the larger your sunroom, the more it will cost. This chart will give you an idea of the average costs to build a sunroom.