Hello, this is my shade (alley) house. It is mostly made from old house yard material and Japanese dollar store products. Everything is DIY with the help of my father
like what everyone have discussed here a few key point you must check off before building one.
Material
Climate / yearly environment (i.e wind and rain are key concern)
and location.
Material:
I use an old metal hatching fence as the skeleton for my roofing, to which I bend and tie them to the house wall and nailed the other end to sturdy wood beams. It is sturdy enough to handle multiple heavy orchids, however, I still dont want to take risk and I am lazy so I went with plastic pot for my hanging orchids/
Shade, I use old car cover as shade cloth and several shade net from Daiso. Daiso sell shade 34.6 x 70.9 in and 36.6 x 140 in for 2-3 dollar at 75%~ (used to be 1.25), since you're from socal, there's a high chance they're at your local Daiso, but you better hurry I might grab them all lol. Or you can just buy them in bulk at their website. Alternatively, Walmart 6x10 ft have at 50%.
General gardening tool. I get all of them from Daiso, from basic tool, orchid support stick, pots, hygrometer, wall hanger, gardening mats, tarps etc, except for copper wires, everything below 5 USD. Hydroponic stores tend to sell cheaper plastic pot in various size, including ones for air plants from last I've seen.
Although I recommend you invest more into your heavy duty tools like cutters, shovel, etc because the ones at Daiso will wear out quickly.
I hand water all of my orchids using the homedepot battery sprayer so I can't help you with an automatic system :P.
Climate:
We probably share the same climate so dry wind and hot summer would be the most concerning issue.
My alley have a gate at the end, I just cover it up with a picnic tarp and use it as a wind shield. Daiso also sell wind breaker mantle (or you can use another shade cloth,) you can just tie them together and make a make shift tent entrance.
Sun protection, if it gets too hot I'd just double the layer of the shade by tying them together with the copper wire. The same goes with Rain.
Location
This is the west side of the house so it will get a lot of sun for the whole 9-10 hours. Which is long enough for the orchid under shade I think.
Use the LUX app or a light meter to measure the ideal lighting intensity for you location. Do it back and fourth every 2 hours of the location and record your data.
The other approach is to buy several instant canopies, replace the cover and use the structure as the skeleton for your shade house.
Another one is trying the Amazon green house. Which is a bit small imo, but may be good enough for beginner. I have no experience with it, so trust this with a grain of salt.