Live loads
Contents |
[edit] Introduction
Loads are forces that may cause stresses, deformations, displacement and accelerations on a building. Different types of load can act upon a structure or building element, the nature of which will vary according to design, location, and so on. Assessing loads forms part of an engineer’s structural calculations – a crucial part of ensuring the safe design of building structures and other built assets such as tunnels, bridges and dams. Design requirements are generally specified in terms of the maximum loads that a structure must be able to withstand.
Loads are generally classified as either live loads (LL) or dead loads (DL).
For more information see: Types of load.
[edit] Live loads
Live loads (also known as applied or imposed loads, or variable actions) may vary over time and often result from the occupancy of a structure. Typical live loads may include; people, the action of wind on an elevation, furniture, vehicles, the weight of the books in a library and so on.
A live load can be expressed either as a uniformly distributed load (UDL) or as one acting on a concentrated area (point load). It may eventually be factored into the calculation of gravity loads. In the UK and much of Europe, live loads are expressed as kilo Newtons per square metre (kN/m2) while in the US the unit is pounds per square foot (PSF).
NB Loads such as wind loading are sometimes considered separately from live loads as environmntal loads. For more information see: Types of load.
[edit] Dead loads
In contrast, dead loads (also known as permanent or static loads, or permanent actions) remain relatively constant over time and comprise, for example, the weight of a building’s structural elements, such as beams, walls, roof and flooring components. Dead loads result from the weight of the structure or other fixed elements before any live loads are taken into consideration. They may include permanent non-structural elements such as partitions, immovable fixtures and even built-in cupboards.
Live loads are added to dead loads to give the total loading exerted on a structure.
For more information see: Dead loads.
[edit] Standards
Eurocode BS EN 1991-1-1:2002 Eurocode 1 Actions on structures (General actions. Densities, self-weight, imposed loads for buildings (formerly BS 6399-1:1996)) is the European code of practice for dead and imposed loads and gives guidance on the structural design of buildings.
[edit] Related articles on Designing Buildings
Featured articles and news
Professional practical experience for Architects in training
The long process to transform the nature of education and professional practical experience in the Architecture profession following recent reports.
A people-first approach to retrofit
Moving away from the destructive paradigm of fabric-first.
International Electrician Day, 10 June 2025
Celebrating the role of electrical engineers from André-Marie Amperè, today and for the future.
New guide for clients launched at Houses of Parliament
'There has never been a more important time for clients to step up and ...ask the right questions'
The impact of recycled slate tiles
Innovation across the decades.
EPC changes for existing buildings
Changes and their context as the new RdSAP methodology comes into use from 15 June.
Skills England publishes Sector skills needs assessments
Priority areas relating to the built environment highlighted and described in brief.
BSRIA HVAC Market Watch - May 2025 Edition
Heat Pump Market Outlook: Policy, Performance & Refrigerant Trends for 2025–2028.
Committing to EDI in construction with CIOB
Built Environment professional bodies deepen commitment to EDI with two new signatories: CIAT and CICES.
Government Grenfell progress report at a glance
Line by line recomendation overview, with links to more details.
An engaging and lively review of his professional life.
Sustainable heating for listed buildings
A problem that needs to be approached intelligently.
50th Golden anniversary ECA Edmundson apprentice award
Deadline for entries has been extended to Friday 27 June, so don't miss out!
CIAT at the London Festival of Architecture
Designing for Everyone: Breaking Barriers in Inclusive Architecture.
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.