Orthogonal plan
The term 'orthogonal' refers to objects that, in Euclidean geometry, are related by perpendicularity. The etymology of the term is the Greek ‘ortho’ meaning ‘right’, and ‘gon’ meaning ‘angled’.
Orthogonal projection is a drawing technique used to represent three-dimensional objects as a series of two-dimensional 'flat' drawings in which there is no perspective.
Orthographic projection is a type of 'parallel' projection in which the four orthogonal views of an object are shown. The orthographic projection commonly used in the UK is called first angle projection.
Buildings are commonly depicted orthogonally by a series of elevations and plans.
The orthographic projection commonly used in the UK is called first angle projection.
The term 'orthogonal plan' may also refer to a type of urban design layout that consists of mostly square street blocks with straight streets intersecting at right angles. This forms a grid pattern, commonly referred to as a ‘grid plan’ or ‘gridiron’.
Orthogonal plans for urban design date back to antiquity, and contributed to the building of some the earliest planned cities. The layout is commonly credited to the 5th-century Greek philosopher Hippodamus, who championed this method of urban planning in his Hippodamian Plan. However, archaeologists have cast doubt on his true claim having found evidence of such plans (more accurately referred to as Milesian layouts) in ancient Egypt.
The regular orthogonal plans of the ancient Greek and Hellenic societies influenced the ancient Romans, who established design principles that are often followed to this day; particularly the work of the engineer Vitruvius.
In a modern context, grid plan urbanism has come to be closely associated with America and recently-redesigned cities such as Barcelona (outside of its historic core).
Although orthogonal plans can help with orientation and enable directness of route due to frequent intersections, the infrastructure cost associated with regular grid patterns is often higher than for patterns with discontinuous streets.
[edit] Related articles on Designing Buildings
Featured articles and news
Shading for housing, a design guide
A look back at embedding a new culture of shading.
The Architectural Technology Awards
The AT Awards 2025 are open for entries!
ECA Blueprint for Electrification
The 'mosaic of interconnected challenges' and how to deliver the UK’s Transition to Clean Power.
Grenfell Tower Principal Contractor Award notice
Tower repair and maintenance contractor announced as demolition contractor.
Passivhaus social homes benefit from heat pump service
Sixteen new homes designed and built to achieve Passivhaus constructed in Dumfries & Galloway.
CABE Publishes Results of 2025 Building Control Survey
Concern over lack of understanding of how roles have changed since the introduction of the BSA 2022.
British Architectural Sculpture 1851-1951
A rich heritage of decorative and figurative sculpture. Book review.
A programme to tackle the lack of diversity.
Independent Building Control review panel
Five members of the newly established, Grenfell Tower Inquiry recommended, panel appointed.
Welsh Recharging Electrical Skills Charter progresses
ECA progressing on the ‘asks’ of the Recharging Electrical Skills Charter at the Senedd in Wales.
A brief history from 1890s to 2020s.
CIOB and CORBON combine forces
To elevate professional standards in Nigeria’s construction industry.
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.