emperor Hadrian (117CE – 138CE) employs an oculus (roof window) to let in unobstructed but diffused light, much like a modern north-facing window or skylight would. Because the sun moves to the south of buildings in the Northern Hemisphere, the northern side of these buildings is always in the shade. For daylighting, this has certain implications: North-facing rooms can feel dark and cool. This can be controlled by painting the room a bright colour such as red, yellow, and orange, finishing the room with wood or by using larger windows. In addition, north light does not change colour (warmth) throughout the day, so whichever mood is achieved through the room's painted colour, it is likely to remain constant. As north light is more diffuse than direct sunlight, it poses less problems with glare. This makes it suitable for office spaces, home theatres or reading rooms. This advantage can help with the previous point – less glare means that larger windows can be used without the need for exterior shading. Infrequently used rooms such as laundries, hallways and bathrooms can be oriented north. This would free up south-facing floor plan space for rooms used more often such as living areas and kitchens. In addition, the latitude of a building changes the effect of north light. Near the equator, the only difference between north and south light may be seasonal. In temperate regions, the implications above apply year-round. In polar areas, they may be even more extreme. For example, Anchorage in Alaska receives only five hours of sunlight at winter solstice, with the sun rising only 5.5 degrees above the horizon. This would make north-facing windows too dark to be of any use during winter. Passive Housing Houses that rely on sunlight, wind and insulation to regulate their temperature (as opposed to artificial cooling and heating) are known as passive houses. Because of its lower brightness and lower amount of infrared radiation, north light transmits less warmth to buildings than direct sunlight does. This makes large north-facing windows better suited for passive houses in warm, tropical climates, as it allows living areas to receive ample sunlight without overheating the building. In Painting North light has been an important feature in painting studios before the development of electric lights, but its use continues to this day. Much like in architecture, light direction is important for the mood of a painting, but the light's