Quantity take-offs and cost estimates

Measuring the works

Quantity take-offs measure the identified works using the available information and agreed criteria. The scope should identify the building areas and design disciplines covered, drawing versions and supporting information used. Quantities that still need confirmation should be clearly identified.

Bills of quantities

The bill organises the works into items with descriptions, units and quantities at the level of detail defined for the enquiry. This structure makes clear what has been measured and relates each item to the intended work. Descriptions should clarify the components included, so that a broad label does not conceal differences between proposals.

Cost estimates

An estimate associates a cost reference with the scope assessed, identifying the information and assumptions used. It can support preparation for a decision or comparison of options. A bill of quantities and an estimate are related deliverables, but the enquiry should clarify whether it covers measurement alone or cost assessment as well.

Bring together the available designs, drawings, specifications and written descriptions. Identify their dates or versions and any known changes not yet incorporated. Preparation should clarify which documents provide the basis and which parts of the work are still being developed.

Where several design disciplines are involved, work at their interfaces needs to be recognised so that measurement can be defined and possible overlaps or gaps identified. A quantity should not be filled in by assumption without that condition being recorded. If site measurements or further information are needed, that work and the corresponding access arrangements should be included in the agreed scope.

Changes made after the reference documents require an identified update. The deliverables should distinguish the initial measurement from revisions and make clear which areas each version covers.

Defining the criteria clarifies how the works will be organised and measured. Lengths, areas, volumes or numbers of units should be related to the item description and supporting information. The same work title can cover different content where the included components have not been identified.

The proposal should state the level of detail and the intended treatment of associated work, removal, preparation or finishing details where these form part of the enquiry. Materials, finishes or equipment still to be selected should be marked as outstanding decisions. Measurement does not replace the technical definition of those elements.

If the bill needs to follow an organisation or criteria already adopted by another party, send that reference. The aim is to prepare a deliverable suited to the intended stage, with criteria and limits that can be read alongside the quantities.

An estimate should identify its reference date, how far the works have been defined and the source of the cost information used. If supplier quotations or other figures are available for review, send them with their scope and conditions. Comparison needs to retain that information, without treating figures for different works as equivalent.

Choices awaiting confirmation, work outside the scope and figures requiring clarification should be identifiable. The deliverable should also explain how charges, taxes or other components have been treated, rather than leaving them implicit in a total. No fixed contingency percentage or uniform price for every intervention is assumed.

The estimate relates to the information and scope assessed. Appointing a contractor depends on the construction proposal and the conditions agreed. Changes to design, supplies or work should be related to the need to revise the cost reference.

A bill can provide a basis for requesting prices for identified works. If the enquiry includes comparison of proposals received, the review should show differences in scope, quantities, inclusions and exclusions alongside the figures. A lower total alone does not establish whether the proposed works are the same.

Support with comparison should have defined deliverables: a schedule of differences, questions to clarify or an updated estimate, according to the scope. Negotiation, appointment and management of construction are tasks to identify where wanted; producing the bill does not automatically include them.

At handover, files should identify the version, reference documents, criteria and outstanding points. Editable formats, organisation into work sections and later revisions are defined in the proposal. When the design changes, the update should make clear what has changed and the information on which the new version is based.

Give the location, type of intervention and the decision you want to support: preparing a request for prices, comparing options or organising an estimate. Send the available information and include:

• Designs, drawings and specifications, with known versions.
• Areas and design disciplines to be measured.
• Work already defined and choices still open.
• Previous bills or estimates and subsequent changes.
• Proposals received, if their comparison is to be included.
• Delivery formats and dates relevant to the decision.

If the design is not yet sufficiently developed, explain the objective and available information. The proposal should identify the level of estimate that can be prepared, the assumptions needed and the information to complete before more detailed measurement can proceed.

• Architectural design

  Develop the architectural decisions and documents that form the basis for measurement.

• Specialist engineering design and coordination

  Define the technical components and interfaces to consider in the measurement.

• Technical direction, construction management and coordination

  Define the management and coordination support required after the works have been identified.

We welcome enquiries in Lisboa, Oeiras, Cascais, Sintra, Amadora, Odivelas and Loures. Availability and the feasibility of the work are assessed for each enquiry.