Defining concrete-frame quantities across towers and basements

We supported a specialist contractor tendering reinforced-concrete works across three towers and a substantial basement. Five bills separated the principal areas of work, supported by a drawing register, marked-up take-offs and a clarification record. The exercise required careful treatment of structural interfaces and design assumptions, followed by further reconciliation when comparison quantities were received.

Background

The tender information combined basement plans, tower drawings and a developing design for one building. The same structural area could therefore appear in more than one drawing set, while some levels and details remained incomplete.

The contractor needed quantities for concrete, reinforcement, formwork and falsework, arranged to support its bid. A useful bill had to explain the measurement boundaries and assumptions as well as identify the principal volumes and areas.

Our approach

We agreed an SMM7 measurement basis and an Excel output broken down by basement level and building. The deliverables comprised a basement bill, separate bills for the three tower structures and a further substructure bill for the building whose design was being considered separately.

The measurement covered slabs, beams, liner and core walls, columns and the associated formwork and falsework. Descriptions distinguished relevant sizes, thicknesses and working-height ranges so that the pricing could reflect the nature of the construction.

A particular interface concerned the relationship between the original basement information and the newer building sketches. At the client’s request, we separated that building’s basement area and measured the alternative detail independently. This preserved a basis for comparing the developing design without silently treating both versions as one coordinated construction arrangement.

The clarification process addressed matters that materially affected quantity. These included whether beam depths were measured below the slab, the dimensions adopted for incomplete sections, the treatment of liner walls against existing retaining construction, and the reinforcement allowances for transfer locations.

We also recorded exclusions and responsibilities. Where stair and landing details were absent, the basis adopted was stated. Items such as water bars, certain service openings and contractor preliminaries were treated in accordance with the agreed scope rather than assumed to form part of every measured section.

The bills were backed by marked-up drawings and calculation records. This retained the reasoning behind the quantities and made it possible to revisit a particular level or component when a query arose.

After the initial issue, comparison quantities were received and we reviewed differences against the retained measurement and clarification record. The working comparison separated original quantities, revised quantities and review comments. It identified the effect of additional detail and items requiring adjustment, with references explaining the basis rather than relying on a single unexplained total.

Outcome

The client received a structured set of tender quantities with the source drawings, assumptions and scope boundaries recorded alongside them. The later comparison provided a route for investigating and adjusting differences within the same measurement framework.

Our contribution was to make a complex structural scope easier to price and interrogate, retaining the detail needed to explain how the quantities had been assembled as the tender information developed.