Maintaining bills of quantities through a changing redevelopment design

We supported a main contractor preparing bills of quantities for a market redevelopment with several buildings and substantial external works. The commission developed into more than 100 elemental bills, with staged issues and later add-and-omit schedules as the design changed. We coordinated measurement, queries, checking and document control so the client could follow both the current quantities and the revisions behind them.

Background

The development brought together new and altered buildings, production spaces, trading areas and external infrastructure. Its measurement needed to cover repeated building elements as well as site preparation, paving, landscaping, fencing, services and drainage.

The information continued to develop after the first bills were prepared. A single final measurement would not meet the client’s needs: packages had to be released in stages, then updated in a way that made the additions and omissions clear.

Our approach

We organised the work by building and element, with a progress tracker recording take-off, bill preparation, checking and issue. This gave the client visibility of which parts were ready and which depended on further information or design development.

Early queries addressed matters that would materially affect the quantities. These included how foundation excavation and mass fill were to be interpreted, whether reinforcement descriptions and allowances overlapped, and what work was needed around existing retaining structures. Where a drawing and its annotation differed, the measurement basis was raised explicitly.

The external-works review also identified information needed to describe the work reliably. Queries concerned the condition and reuse of existing sub-base material, the basis of levels and the absence of drainage details such as chambers, backdrops and attenuation information. These were recorded as specific questions rather than absorbed into unexplained allowances.

Initial bills were issued in stages, followed by controlled updates as the design progressed. The tracker retained earlier versions alongside the current position, allowing the building and element affected by each issue to be identified. The records span the initial early-summer submissions through further updates later in the season.

Later revisions were measured as additions and omissions. This retained the link to the previous bill and made the effect of revised design visible without requiring the client to compare two complete documents line by line.

The drainage update demonstrates the level of detail. It distinguished removed channel lengths and fittings from the revised channels, outlets and access points. Pipe trenches were separated by pipe size and depth, with excavation, disposal, support and backfilling described as part of the measurement basis.

The resurfacing review dealt with a different issue: the regulation needed beneath the finished surface. The additional bill separated areas by thickness band so that the underlying work was visible alongside the resurfacing description.

We coordinated the queries and revised submissions with the client and the measurement team, retaining marked-up records and issuing the bills in Excel and CITE formats. This supported the client’s use of the information within its estimating process.

Outcome

The client had a structured set of bills and revision records across the buildings and external works, with updated quantities capable of being traced through the successive issues. The add-and-omit approach made later design changes easier to identify and price.

The value extended beyond producing quantities. We maintained continuity between the original information, the questions raised and the changing scope, giving the client a clearer record to use as the redevelopment progressed.