- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 05 Feb 2018
Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by ‘projecting’ its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
In the construction industry, the term ‘elevation’ refers to an orthographic projection of the exterior (or sometimes the interior) faces of a building, that is a two-dimensional drawing of the building’s façades. As buildings are rarely simple rectangular shapes in plan, an elevation drawing is a first angle projection that shows all parts of the building as seen from a particular direction with the perspective flattened. Generally, elevations are produced for four directional views, for example, north, south, east, west.
Simple elevation drawings might show:
- The outline of a building.
- Openings such as doors and windows.
- Projections such as eves and pipes.
- Level datums such as finished ground level and floor positions.
- Key dimensions such as wall lengths and heights.
- Exterior features such as decks, porches and steps.
- Any portion of the foundation that may be visible.
- Exterior wall and roof finishes.
However, they can contain a great deal of detail depending on the reason for their preparation. Whilst insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be very time consuming and so expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
Elevations might be prepared for a number of reasons, including:
- As part of a survey of existing buildings.
- To create a record of a building.
- To explore and communicate interior and exterior design options.
- To communicate construction information.
- As part of an application for planning permission.
- As part of an application for building regulations approval.
- For sales and marketing.
Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
 Related articles on Designing Buildings Wiki
- As-built drawings and record drawings
- Assembly drawing.
- Building information modelling.
- CAD layer.
- Component drawing.
- Computer aided design.
- Concept drawing.
- Detail drawing.
- Engineering drawing.
- Exploded view.
- Floor plan.
- General arrangement drawing.
- How to draw a floor plan.
- Installation drawings.
- North American Paper Sizes
- Notation and symbols.
- Orthogonal plan.
- Paper sizes.
- Principal elevation.
- Production information.
- Scale drawing.
- Shop drawings.
- Site plan.
- Standard hatching styles for drawings.
- Technical drawing.
- Techniques for drawing buildings.
- Types of drawings for building design.
- Working drawing.
 External references
- The House Plans Guide – Elevation drawings
Featured articles and news
Grouting refers to the injection of materials into a soil or rock formation to change its physical characteristics.
Part of Designing Buildings Wiki, BREEAM Wiki will advance knowledge sharing for the BRE family of sustainability tools.
From the decorative to the utilitarian, and from the photographed to the forgotten.
New BRE book considers the progression from project-based knowledge creation to whole-life urban knowledge management.
This CIOB article explores the concept of value in building design and construction.
BREEAM and Measurabl announce integration to improve the financial performance of commercial real estate.
Rogers Stirk Harbour + Partners' release new images of soon-to-open 3WTC tower in New York.
A document can be called a bond or a guarantee. Does the name matter and what is the difference between them?
New briefing note is launched focusing on increasing knowledge of housing that promotes health and wellbeing.
Arbitration is a private, contractual form of dispute resolution used in the construction industry.
The European Parliament has approved a revised Energy Performance of Buildings directive.
One in six MPs supports the ring-fencing of retentions as proposed in the 'Aldous Bill'.