Expect to pay $5,000 to $35,000 to convert your patio to a sunroom. How Much Does It Cost to Build a Sunroom Without an Existing Foundation? Three seasons sunrooms cost $80 to $230 per square foot. Four seasons sunrooms cost $200 to $400 per square foot. It costs $10,000 to $90,000 to remove the concrete and build a sunroom from the ground up.

According to fixr.com, the average cost of converting a sunroom, including the poured slab, post and beam construction, and the creation of a four-season room, is around $72,000 or $360 per square foot. This estimate includes an average of $70 per hour for carpentry work and $65 to $85 an hour for electrician work.

On average, converting a screen porch to a sunroom runs between $100 to $300 per square foot. A three-season room conversion will cost about $8,000 to $50,000. Turning your screened porch into a four-season room can cost $20,000 to $80,000.

For a minimal patio conversion, you can expect to spend anywhere from $3,000 to $10,000. Going the whole hog (turning your patio into a fully enclosed second living space with a solid roof, walls with big windows, and a new floor) will cost you more, probably between $20,000 and $35,000.