The most commonly used electric light bulbs in residential buildings are standard incandescent light bulbs, can be very energy inefficient compared to other types of electric light bulbs. Fluorescent lighting may yield three to four times the amount of light per watt consumed compared to standard incandescent light bulbs. The compact fluorescent lamp (CFL) is one of the most important developments in lighting in recent years. The CFL may last up to thirteen times as long as standard incandescents, and use one-quarter of the electricity. Fluorescent light bulbs have not been used more for reasons such as perceived lowered quality of light and delays or flickers in switching them on, though improved CFLs have reduced or eliminated these problems. Though CFL may be much more expensive than incandescent bulbs, their longevity and energy efficiency can lead to better investment returns. Improvements of tube fluorescents and incandescents are being made.
The use of "free" sunlight in building design such as skylights, lightpipes and atria can be maximized, and has become a more viable option due to improved energy efficiency in window technology. Other strategies include task lighting (providing higher lighting levels only where they are needed), lighting controls such as dimmers (control light intensity), timers (switch lights on/off at pre-designated times), and sensors (turn lights on in response to actual conditions, such as presence of person).