Patio-to-sunroom conversion in Eastvale CA - a room planned around your slab and yard

In nearby Corona, a three-season sunroom on an existing base with standard windows and roofing usually runs about $130 to $190 per square foot. That's the going rate in the region, not our price, and insulation, heating and cooling equipment, plumbing and permits add to it. I'll give you your own figure after I've seen your patio.

An unheated sunroom stays closed off from the house, while one that opens into it counts as part of your living space. The industry's sunroom specification calls the closed-off kind a thermally isolated room, one that's neither heated nor cooled and can have glass or plastic in its openings, and a heated or cooled room open to the house has to meet requirements for air leakage, water getting in and heat performance, so you plan for better glass and doors. The state Energy Code also sets energy, water and indoor air requirements for additions to a house, which matters most when the room is part of the home. If you mostly want a shaded spot for mornings and evenings, I usually steer people to the closed-off room because it's simpler and costs less.

Make sure the license covers both the enclosure and any structural work in your plan, because a couple of common licenses don't. The state's contractor license board lets an awning contractor install patio covers but not patio enclosures, and it bars a residential remodeling contractor from contracting changes to load-bearing parts like footings, foundations, walls and roof structures. So match the license to what your plan actually includes.

Usually it's a slab that sits too close to the level of the yard, so rain and sprinkler water pool against the base. One maker's installation guide says the foundation has to sit higher than the ground around it, because standing water gets into the bottom tracks and then into the room. If your slab is low, it's much easier to deal with the grading before the walls go up than after.

A yearly look at the roof and gutters covers most of it, and that's what one sunroom maker's owner guide suggests. A clogged gutter or a loose panel is a small fix when you catch it early. Keep the bottom tracks clear of dirt and leaves too, so water has somewhere to go.

Sometimes, but I won't know until I've looked at how the cover is framed and tied to the house. A lot of covers are built only to shade a patio, not to carry walls, windows and doors, so the roof may need reinforcing or replacing. That's one of the bigger things that moves the price, which is why I check it at the estimate.