Extra over (EO)
‘Extra over’ (EO) is a term that is often used when taking off for a bill of quantities (BoQ). Taking off is the process of identifying elements of construction works that can be measured and priced.
When taking off for a BoQ, the term ‘extra over’ can be used to refer to items that to a certain extent have already been measured, but have not been priced at the full value of all their labour and materials. A common example of this is when measuring drain pipes, for which the estimator may determine a cost based on the full length of the pipe measured along its centre-line, and then assess an ‘extra over’ cost for the additional cost necessary to pay for fittings such as bends and junctions. So the cost of a section of pipe with a bend is the cost of the length of the pipe plus the extra over cost for the bend.
EO items should be listed directly beneath the main item over which they are measured, as this simplifies the the interpretation of the BoQ by suppliers. If the EO item cannot be listed immediately beneath, reference should be given in its description in the main item it relates to.
[edit] Related articles on Designing Buildings Wiki
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
New and updated CLC building safety guidance.
New UK National Buildings Database.
Building Safety Wiki Interviews
Chief executive of the British Woodworking Federation.
Planning condition discharge in England and Wales
A brief explanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
Comments
good explanation