Final answer:
Cladding or siding, made of materials like metal, wood, vinyl, or composites, is commonly used on building envelopes to protect against rain. Solar panels may also serve as a secondary barrier and provide energy but can be impaired by partial shading.
Step-by-step explanation:
The panels commonly put on a building envelope to keep rain out are known as cladding or siding. These are materials that are attached to the exterior of a building to protect it from the weather. Their primary role is to prevent water from penetrating into the building while also adding to the aesthetic of the structure. They can be made from various materials, including metal, wood, plastic (vinyl), masonry, or composite materials. The right choice of cladding material is crucial, especially in geographical areas where rain or snow is frequent, as it can drastically affect the durability and maintenance requirements of the building envelope.
In addition to cladding for protection against rain, modern building designs may incorporate solar panels, which can be mounted on roofs or walls. These are not primarily for keeping out rain but do provide the added advantage of generating electricity while also acting as an additional barrier against the elements. However, the effectiveness of solar panels can be compromised by partial shading, as noted in the provided reference material.