A solarium is defined as what type of room?

A solarium is specifically characterized as a room that is mostly glass, designed to allow an abundance of natural light to enter. This bright, airy space typically serves the purpose of providing a connection with the outdoors while offering protection from the elements. Solariums are often used for relaxation, gardening, or as additional living space where plants can thrive due to the increased sunlight exposure. The use of large glass panels helps in not only maximizing light but also in adding aesthetic value to a home, making it a suitable environment for enjoying the outdoors in a controlled climate.

In contrast, a room with minimal windows would not facilitate the same level of light and outdoor connection, while an underground room typically lacks natural light altogether. A room made of concrete might not necessarily include glass as a prominent feature, which is essential in a solarium's design. Therefore, the defining characteristic of a solarium aligns precisely with being a room that is predominantly made of glass.