Greenhouse cultivation relies on adequate sunlight for vegetable growth, thus, choosing a site with sufficient sunlight is crucial for constructing vegetable greenhouses.

The distance from the southern-facing structures, trees, and other shading elements of the greenhouse construction base to the front row of greenhouses should be no less than the length of the shading object, with the shading point casting shadows at the length measured in the afternoon of the "Winter Solstice."

The distance from the shading and canopy structures to the front of the greenhouse, facing either southeast or southwest, should be no less than the shadow length cast by the shading point of the canopy structure at noon on the "Winter Solstice."

The construction of such greenhouses is justified, as they provide optimal ventilation and lighting conditions for vegetable cultivation.