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.