What is a building material starting with the letter "E"?

Electrical wire is a common building and construction material that begins with the letter "E". It has a wide range of applications both in wiring a house or structure and in later incorporating new systems and devices into that wiring.

Electrical wire comes in many different varieties, from plated cords used for heavy-duty circuitry to thinner cords used in home wiring. They compose the bulk of the average home's internal electrical circuit system.

Electricians use electrical wiring in most of their work. For installing things like security systems or garage door openers, the wires are vital for patching such tools into the electrical systems already present.