When the leaves fall in the winter, deciduous trees allow solar heat to reach the building. DWP offers a free booklet about shade trees titled, Smart Planting for the New Urban Forest. Trellises Trellises are permanent structures that partially shade the outside of a building. Clinging vines growing over the trellis can add more shade. Vines also provide evaporative cooling as the plants pump water from the soil.
Trellises can shade windows, walls and outdoor-living areas.
They also can shade air conditioners, heat pumps and evaporative coolers, so the equipment works better and uses less electricity. Large trellises, supported by posts, can cover a patio or provide shade for several windows. Smaller, wall-mounted trellises may shade only one window. Fast growing vines create shade quickly, while trees can take years to provide useful shade. Deciduous vines lose their leaves in winter allowing the sun's heat to strike the building.