Roof in the context of "Wall"

A building or edifice is an enclosed structure with a roof, walls and often windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for numerous factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, prestige, and aesthetic reasons. To better understand the concept, see Nonbuilding structure for contrast.

Buildings serve several societal needs – occupancy, primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical separation of the human habitat (a place of comfort and safety) from the outside (a place that may be harsh and harmful at times).

A house is a single-unit residential building. It may range in complexity from a rudimentary hut to a complex structure of wood, masonry, concrete or other material, outfitted with plumbing, electrical, and heating, ventilation, and air conditioning systems. Houses use a range of different roofing systems to keep precipitation such as rain from getting into the dwelling space. Houses generally have doors or locks to secure the dwelling space and protect its inhabitants and contents from burglars or other trespassers. Most conventional modern houses in Western cultures will contain one or more bedrooms and bathrooms, a kitchen or cooking area, and a living room. A house may have a separate dining room, or the eating area may be integrated into the kitchen or another room. Some large houses in North America have a recreation room. In traditional agriculture-oriented societies, domestic animals such as chickens or larger livestock (like cattle) may share part of the house with humans.

The social unit that lives in a house is known as a household. Most commonly, a household is a family unit of some kind, although households may also have other social groups, such as roommates or, in a rooming house, unconnected individuals, that typically use a house as their home. Some houses only have a dwelling space for one family or similar-sized group; larger houses called townhouses or row houses may contain numerous family dwellings in the same structure. A house may be accompanied by outbuildings, such as a garage for vehicles or a shed for gardening equipment and tools. A house may have a backyard, a front yard or both, which serve as additional areas where inhabitants can relax, eat, or exercise.

A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent material, a sash set in a frame in the opening; the sash and frame are also referred to as a window. Many glazed windows may be opened, to allow ventilation, or closed to exclude inclement weather. Windows may have a latch or similar mechanism to lock the window shut or to hold it open by various amounts.

Types include the eyebrow window, fixed windows, hexagonal windows, single-hung, and double-hung sash windows, horizontal sliding sash windows, casement windows, awning windows, hopper windows, tilt, and slide windows (often door-sized), tilt and turn windows, transom windows, sidelight windows, jalousie or louvered windows, clerestory windows, lancet windows, skylights, roof windows, roof lanterns, bay windows, oriel windows, thermal, or Diocletian, windows, picture windows, rose windows, emergency exit windows, stained glass windows, French windows, panel windows, double/triple-paned windows, and witch windows.

Slate is a fine-grained, foliated, homogeneous, metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism. It is the finest-grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression.

The foliation in slate, called "slaty cleavage", is caused by strong compression in which fine-grained clay forms flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation with a specialized tool in the quarry, many slates display a property called fissility, forming smooth, flat sheets of stone which have long been used for roofing, floor tiles, and billiard tables. Slate is frequently grey in color, especially when seen en masse covering roofs. However, slate occurs in a variety of colors even from a single locality; for example, slate from North Wales can be found in many shades of grey, from pale to dark, and may also be purple, green, or cyan. Slate is not to be confused with shale, from which it may be formed, or schist.

Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to channel runoff (or stream flow). It occurs when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is saturated by water to its full capacity, and the rain arrives more quickly than the soil can absorb it. Surface runoff often occurs because impervious areas (such as roofs and pavement) do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or human-made processes.

Surface runoff is a major component of the water cycle. It is the primary agent of soil erosion by water. The land area producing runoff that drains to a common point is called a drainage basin.