Checking a refurbishment bill of quantities against the design

We supported a main contractor reviewing an existing bill of quantities for a substantial refurbishment and extension. The tender information contained more than 2,000 drawings, surveys and other files, with the initial review focused on finishing trades and envelope work. We checked selected bill sections against the design and specifications, identifying missing items, quantity differences and duplicated allowances before the contractor relied on the bill for pricing.

Background

The scheme combined work to an existing multi-level building with a new extension. Its bill separated refurbishment, conversion and fitting-out work from the new construction, with further references to surveys, schedules and specialist requirements.

The client needed additional quantity surveying capacity to test whether the selected sections represented the information it had received. A useful review had to go beyond recalculating quantities: an apparently complete bill could still omit a drawing requirement, duplicate an allowance or rely on a superseded document.

Our approach

We agreed a focused review with the estimating team. The initial parameters covered the reasonableness of measured quantities, the relevance of referenced drawings and specifications, and work shown in the design that did not appear in the bill. The task was a targeted verification exercise, with the scope and remaining work kept visible.

The drawing register compared the issue-sheet revision with the version actually received. That allowed gaps and revision differences to be identified before a quantity was treated as checked. The record covered plans, sections, elevations, detailed schedules and finishes information.

We then structured the bill review so that the original description and quantity remained alongside our quantity, the variance and the supporting drawing reference. Separate fields recorded the drawing and specification checks, comments and additional items. The client could therefore follow a finding back to both the original bill and its source.

The window and external-door review illustrated the value of that approach. The checked sections identified glazing that had not been measured, sealant quantities requiring attention and ironmongery work that was either duplicated or omitted. A dozen additional items were identified within two of those bill sections.

The review also compared finishes with the wider design requirements. It identified apparent differences in the extent of acoustic floor work and work described in historic-repair information that was not represented in the bill. Where the drawings or schedules remained unclear, the issue was recorded rather than converted into an unsupported quantity.

A summary sheet brought the findings and review status together by bill section. It distinguished completed checks from sections still being worked through, helping the estimating team see both the issues raised and the extent of the verification undertaken.

This format made the review usable. It provided more than a list of concerns: the original item, the proposed correction or additional scope, the reference and the reason could be considered together.

Outcome

The review produced an annotated bill and drawing reconciliation that made omissions, potential overmeasurement and unresolved design questions visible to the contractor’s estimating team. The record gave it a defined basis for refining the pricing information and directing further enquiries.

Our contribution was to test the content behind the bill, helping the client understand where the selected sections reflected the design and where further work was needed before the commercial position could be relied on.