On site
The term ‘on site’ (or on-site) typically refers to work which is carried out on the construction site itself. This is as opposed to ‘off-site’ which is generally associated with prefabrication or pre-assembly techniques. For more information see: Offsite construction.
Generally, on-site construction techniques tend to be more labour and time intensive, and they may have lower quality due to the complexities of working in an uncontrolled environment, subject to weather and other changeable conditions, space and access restrictions and so on. However, they can be more flexible in response to changes that may arise on site.
See also: In situ.
Workers on a project may be described as ‘on site’ or ‘off site’.
On site may also refer to the storage of materials. This is as opposed to off site materials, where the client has paid for materials, but they have yet to be delivered to site. The client may do this to ‘reserve’ the items, protecting the programme, but this does put the client at risk, for example if the contractor becomes insolvent and the items are then not delivered, even though payment has been made. For more information see: Off site materials.
On site may also refer to the generation of heat and / or power. Localised, point generation of heat and power provides an independent, responsive, sustainable method of supply. On-site generation can include renewable energy technologies, such as photovoltaics, anaerobic digestion, wind turbines, water turbines, combined heat and power (CHP) and so on. For more information see: On site generation of heat and power.
The feed-in tariff scheme allows consumers who generate their own electricity from a renewable or low-carbon source to qualify for a payment for each unit of electricity generated. Consumers can also qualify for an ‘export tariff’ by selling surplus electricity back to their supplier. For more information see: Feed-in tariff.
The renewable heat incentive (RHI) is similar to the feed in tariff scheme, but is designed to incentivise heat generation. For more information see: Renewable heat incentive.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
Guidance notes to prepare for April ERA changes
From the Electrical Contractors' Association Employee Relations team.
Significant changes to be seen from the new ERA in 2026 and 2027, starting on 6 April 2026.
First aid in the modern workplace with St John Ambulance.
Ireland's National Residential Retrofit Plan
Staged initiatives introduced step by step.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.
Reflecting on the work of the CIOB Academy
Looking back on 2025 and where it's going next.
Procurement in construction: Knowledge hub
Brief, overview, key articles and over 1000 more covering procurement.
Sir John Betjeman’s love of Victorian church architecture.
Exchange for Change for UK deposit return scheme
The UK Deposit Management Organisation established to deliver Deposit Return Scheme unveils trading name.
A guide to integrating heat pumps
As the Future Homes Standard approaches Future Homes Hub publishes hints and tips for Architects and Architectural Technologists.
BSR as a standalone body; statements, key roles, context
Statements from key figures in key and changing roles.
Resident engagement as the key to successful retrofits
Retrofit is about people, not just buildings, from early starts to beyond handover.