Section drawing
A 'section drawing', 'section' or 'sectional drawing' shows a view of a structure as though it had been sliced in half or cut along another imaginary plane.
For buildings, this can be useful as it gives a view through the spaces and surrounding structures (typically across a vertical plane) that can reveal the relationships between the different parts of the buildings that might not be apparent on plan drawings. Plan drawings are in fact a type of section, but they cut through the building on a horizontal rather than vertical plane.
The direction of the plane through which the section is cut is often represented on plan drawings and elevations by a line of long and short dashes, called a section plane. If there are a number of sections, the line may have letters at each end indicating the name of the section drawing and an arrow showing the direction that the view takes.
The section line can take an indirect route through a building if this helps show the most important features or junctions in the building, as illustrated on the drawing below.
In this case, the section drawing would be named 'Section B-B'.
Shading, cross hatching or other fill styles and / or thicker lines can be used to indicate parts of the structure that have been cut through, such as walls, roofs and floors.
The scale of a section drawing will depend on the size of the building being drawn and the level of detail that needs to be shown. Sections may show the entire building, or may focus on a particular component, junction or assembly. In this case they can be similar to assembly drawings but differ in that they don’t usually include details of the actually assembly process.
Different types of cross hatching can be used to differentiate between different types of component on detailed sectional drawings. Standards exist for hatching that should be used on some common materials, for example, double diagonal lines indicate brickwork, a wave indicates insulation and so on.
Perspective sections include 3D projection of the spaces beyond the section plane and can be used to give a graphical illustration of the relationship between spaces and building components as well as their depths that can be very helpful in trying to interpret a complex design.
Increasingly, section drawings can be generated automatically by 3D modelling software, including perspective sections where required.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- As-built drawings and record drawings.
- Assembly drawing.
- Building information modelling.
- Component drawing.
- Computer aided design.
- Concept drawing.
- Design drawings.
- Detail drawing.
- Engineering drawing.
- General arrangement drawing.
- How to draw a floor plan.
- Installation drawings.
- Manual of Section - review.
- North American Paper Sizes
- Notation and symbols.
- Paper sizes.
- Production information.
- Projections.
- Scale drawing.
- Shop drawings.
- Site plan.
- Technical drawing.
- Types of drawings for building design.
- Working drawing.
[edit] External references
- ‘Building Construction Handbook’ (6th ed.), CHUDLEY, R. and GREENO, R., Butterworth-Heinemann (2007)
Featured articles and news
A sun, tide, mass or scratch dial.
A brief description of time in the sun.
ICE Trustee Board update June 2022
Given by ICE President Ed McCann.
Artificial intelligence and project management
Two new research reports published by APM.
Association for Project Management membership offer
50% off APM Associate membership for Designing Buildings users.
Building safety, a shifting landscape for professionals
A commentary from the insurance perspective.
In brief with further links.
Walter Segal: self-built architect
A definitive book on a pioneer of green architecture.
Funding for heritage on the high street
Using heritage as a catalyst for reviving historic centres.
Commonwealth Heads of Government Meeting update.
Declaration prioritising sustainable urbanisation adopted.
A small hidden, often distant but key building component.
Some brief words about the actuator.
CIAT Chief Executive steps down.
After 34 years at the Institute.
Volunteer opportunity launched by the ICE
To support the next generation of engineers.
Provisional findings show illegal cartels in the industry.
CIAT reporting from the Competition and Markets Authority.
Making sustainable construction number one priority.
The future of construction report.
Interview with ECA CEO.
Many provisions came into force on June 28, 2022.
With room to expand.
An information packed session at the BSRIA conference.
Refurbishment, Energy Efficiency, Indoor air and process.
Create a profile, write informed product articles and share.
Aluminium Composite Panels (ACP) is one example.
We are indeed now 10 years old, so go on and be bold !
Write about something you know, help us build and grow !