Your reasoning is exactly correct. Some people put the shade cloth inside because it is sometimes easier, but this would result in considerably less cooling effect.

ibcdvm, For sure, put the cloth on the outside. Another tip is to attach the cloth so as to have at least a couple of inches of air between the outer covering of the house and the cloth. This permits air to flow between the cloth and the house. Allowing the cloth to lay on the house is much like putting a blanket over the house.

My little "curved top/side house made that pretty easy, but some of the larger straight sided/flat angled roofed houses are difficult. I attached the cloth at the peak of the house, and built a bar across the length of the house about half way down, and put the cloth over the bar, and attached it to stakes in the ground several feet away from the side of the house. The wind in Kansas (when we lived there) sometimes gave me a problem, but was nothing I could not repair.

I actually had enough room between the cloth and the house at ground level that I could put plants under the shade outside in summer.

Bill

Can't visualize any situation where it would be easier to put shade cloth on the inside of a greenhouse. I prefer to have ropes that stay in place over the structure when the shade cloth is laying on on side of the greenhouse. The mule rope from ÑEPTCO works well for this. Pulling the shade cloth over and tying in place is a quick and one person can do it. After all if you have a period of overcast weather you don't want shade cloth covering your structure.

I don't know about the air space but the moment that shade cloth covers one of my structures the temperature drops considerably. Sometimes I'll pull it over just to make inside tasks more comfortable. If you are going to install shade cloth outside you'll need ropes thrown over the greenhouse first anyhow in order to pull the cloth into place. Just tie one side so the cloth doesn't go completely over and provide enough rope on the pulling side to allow the cloth to slide completely back and still have a tied rope in place.

The size of the greenhouse needs to be considered. A
lightly, colored interior shade would be preferred for larger greenhouses,
especially if it is motorized. This will increase the lifespan of an expensive
accessory. The light color will help reflect visible light, rather than
converting the energy to heat. On smaller greenhouse lacking sufficient natural
ventilation, the exterior shade cloths are probably the best solution. However,
be prepared to budget for a new one every five years or so, depending upon the
harshness of your location’s climate and solar intensity.