I would go with a patio cover with real roofing of some kind. The lattice is useless. It won’t provide cover from the sun or shelter for your outdoor furniture,

Depends on how fancy you want it and if you want to get a permit. Do you already have anchors for the posts? I’d say $2,000 and up. You may not be able to build it you have a small lot with setback requirements (check with the city).

I would go with a patio cover with real roofing of some kind. The lattice is useless. It won’t provide cover from the sun or shelter for your outdoor furniture,

This is a good idea. Usually people want these things by the rear sliding glass door. It is better to actually protect this area of the house from the elements for preservation of the house,comfort and cleanliness.
If you go with lattice put a rain shield of some type over the first few feet around the door(if there is a door).

I spent a year building patio covers for a living. YOur price for a 12×20 should be between $3000 and $10K depending on a lot of factors, such as if you use prefab vinyl or wood, and how many decorative enhancements like routering edges and decorative corbels you want. Also, you can save money by going with thinner wood, like 4×4 posts vs more sturdy 6×6 posts, and 1×6 joists vs 2×8’s. YOu’ll have a thinner, toothpick looking result, but you’ll save money.

I disagree that using lattice, or those parallel slats you see on a typical SoCal patio cover, is useless. It blocks out a large percentage of sun and reduces the temp of your patio by a great deal. Full roofs block 100% and lower temps a little more, but lattice still works, and looks nice.

Get three quotes… you should see a range between $3K and $10K.

Go to J & W Redwood with your measurements. they will spec out all the wood and hardware you will need based on your measurements. This is an easy do-it yourself project and will cost you only for materials. If you hire someone, just double the materials cost and you will have a ballpark figure. I estimate materials at $2000. So your total cost is around $4-5K.
I used Redwood to build 3 10X12 patio covers and they came out great. I also stained instead of painted. It cost me $1,500. However, this was in 2001 and i am sure the price of wood has gone up considerably. If I had to do it over again, I would seriously consider some of the new composites like TREX. Supposedly lasts forever. with little maintainance. Porkman

Pre fab aluminium can be cheaper than wood if you use a pre made kit that doesn’t allow for customization. If you need a specific size or shape and a pre made aluminium kit won’t work, customizing aluminum to fit your needs can get more expensive than using wood. Good wood, with proper treatment, will resist rot for a very long time. Some people love natural wood, others don’t care.

I don’t recommend doing it your self, much of the job is a two person effort, especially if you use larger wood. Hoisting a 20′ 4×12 frame member 12 feet up in the air is not easy by your self.

Also there are plenty of codes that need to be followed, not the least of which is how you mount the ledger to your house. Mess that up and the problems are immense.

Another thing, your cost will vary depending on if you get a licensed contractor who gets a permit, or a free lance carpenter guy who doesn’t get a permit. Its your choice, but I think the risk of potentially having to tear it all apart and start over outweighs any potential savings.