A shed, outhouse, outbuilding or shack, is typically a simple, single-storey roofed structure in a back garden or on an allotment that is used for storage, hobbies, or as a workshop.

Sheds vary considerably in the complexity of their construction and their size, from small open-sided tin-roofed structures to large wood-framed sheds with shingled roofs, windows, and electrical outlets. Sheds used on farms or in industry can be large structures. The main types of shed construction are metal sheathing over a metal frame, plastic sheathing and frame, all-wood construction, and vinyl-sided sheds built over a wooden frame.

Types Small domestic sheds.

The simplest and least-expensive sheds are available in kit form. Both shed kits and "do-it-yourself" plans are available for wooden and plastic sheds. Sheds are used to store home and garden tools and equipment such as lawn tractors, and gardening supplies. In addition, sheds can be used to store items that are not suitable for indoor storage, such as petrol (gasoline), pesticides, or herbicides.

For homes with small gardens or modest storage needs, there are several types of very small sheds. The sheds not only use less ground area but also have a low profile less likely to obstruct the view or clash with the landscaping.

Types Construction Specific-use sheds.

The main types of shed construction are metal sheathing over a metal frame, plastic sheathing and frame, all-wood construction, and vinyl-sided sheds built over a wooden frame. Each type has various advantages and disadvantages that a homeowner has to consider. For example, while metal sheds are fire and termite-resistant, they can rust over time, or be severely damaged by high winds.

Garden Sheds.
The vast majority of sheds are garden sheds, including allotment sheds. This class of sheds also includes potting sheds and tool sheds. Most modern gardens are too small for more than a single shed, containing garden tools and lawn mowers.

Metal sheds.
Metal sheds made from thin sheet metal sheathing (galvanized steel, aluminium, or corrugated iron) attached to a metal frame. Metal sheds are a good choice when long-term strength and resistance to fire, rot, or termites is desired. However, metal sheds may rust over time, particularly if they are constructed from steel that is not galvanized. Be aware that concrete is highly corrosive so care needs to be taken when assembling your shed to avoid contact with the outside panels.

Plastic sheds.
Plastic shed kits utilizing heavy molded plastics such as PVC and polyethylene are less expensive than sheet-metal sheds. PVC resins and high-impact, UV light-resistant polyethylene make plastic outdoor sheds stronger, lighter, more durable, and more resistant to denting and chipping than wood, and tend to be more stable.

Plastic sheds are not susceptible to termite or wood-boring insect damage, and they require little maintenance. Being rot-proof they do not need to have preservative applied.

Wooden sheds.
Wooden sheds have a natural look that can blend in well with garden environments. Despite the strength of wood, over time, untreated and neglected wood can rot, split, warp or become susceptible to mold and mildew, so wood sheds should be treated for protection. Wood sheds need regular maintenance. This includes keeping plant matter and debris from piling up beside the walls and on the roof, and occasional rot-proofing with preservative. Sheds are sometimes also re-stained or varnished at times for aesthetic reasons. Fire and, in some regions, termite attack are also potential problems.

One advantage of using wood sheds over metal versions is that it is easier to modify them by adding windows, doors, shelving, or exterior trim (etc.) because wood can be cut and drilled using commonly available tools. Some homeowners may prefer wood sheds because wood is a renewable resource.