> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/maps-and-imagery-portfolio/os-mastermap-topography-layer/os-mastermap-topography-layer-technical-specification/product-themes/buildings.md).

# Buildings

Buildings are defined as permanent roofed constructions, usually with walls. This includes permanent roofed constructions that exceed 8.0m² in area (12.0m² in private gardens). Exceptions are made to this area rule for smaller buildings that, due to their detached position, form relatively important topographic features; these are shown at minimum size, as stated above. With a few exceptions (for example, by describing government offices or hypermarkets), no distinction is currently made between residential, private, public, commercial, or industrial buildings.

Physical features shown in the Buildings theme include:

* Roofed Buildings (identified as being of sufficient size or importance to be shown)
* Mobile or Park Homes that are permanent, residential and have a postal address
* Archways and Covered Passageways, where the alignment can be determined from outside the building
* Horticultural Glasshouses over 50m²
* Covered Tanks

Features such as cooling towers, uncovered tanks, bridges, and monuments are shown within the Structures theme.

Only glasshouses over 50m² that serve a horticultural purpose will continue to be captured as glass structures. Other glass structures, such as office buildings and conservatories, exist within OS MasterMap and will be recorded as buildings. There are some non-physical features shown in the Buildings theme, represented as the following text features:

* House Numbers
* Descriptive Building Names
* Distinctive Building Names

Detail in private gardens attached to residential buildings, such as sheds, pathways and ornamental ponds, is not captured as part of the specification. Where possible, all gardens of this type are generalised and represented by a single garden polygon.


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