Before you price a subcontract package, you need more than a marked-up drawing and a rough total. A good trade take-off shows what has been measured, which information was used, what has been assumed and where your work starts and ends.
This applies to packages such as groundworks, brickwork, drylining, roofing, joinery, flooring, painting and building services. Measurement guidance from RICS covers the detailed information needed for bills of quantities, schedules and work packages. It also separates matters such as site running costs, risks, design duties, overheads and profit. See RICS NRM 2.
1. Gather and check the tender information
Start by recording exactly which documents you are using. Note each drawing’s number, title, revision, date and status. Do not assume a file is current just because its name says “latest”. Check that the architectural, structural and services information agrees, and look for later changes that affect your work.
Your document set may include plans, elevations, sections, detail drawings, structural information, room and door schedules, finish schedules, specifications, employer’s requirements, programme details, access information and tender queries. Include any written answers or addenda issued during the tender.
If a digital building model is supplied, check it against the drawings and written requirements before using its measurements. Confirm its status, purpose and supporting information. A model can help you review the design, find clashes and inspect quantities, but its information still needs to be understood and checked. The RICS guidance on BIM at tender stage explains this further.
2. Set the package boundary
Write a short scope statement before measuring. It should say what work is included, which buildings or areas are covered and what standard of finish is expected.
For example, a drylining package might include metal framing, boards, insulation, access panels and fire protection within the system. It might not include decoration, specialist doors, structural openings, service penetrations or final sealant. State these boundaries clearly instead of expecting the estimator or subcontractor to guess.
Check each connection with another trade. Who forms and trims openings? Who supplies fixings, brackets and supports? Who installs fire stopping and sealants? Who protects finished work and removes waste? Who handles testing, samples, setting out and making good? These tasks can add cost even when they are not obvious on the main drawing.
3. Measure in a way others can follow
Choose a consistent structure. Group the work by building, floor, room, zone, elevation or system. Keep the description, dimensions, quantity and unit together. Use units such as square metres, linear metres, cubic metres, kilograms or number.
Each entry should normally show:
- What the item is and where it is located.
- The material, system or specification reference.
- The dimensions or calculation used.
- Openings, deductions and how waste has been treated.
- Related fixings, accessories, preparation or sundries.
- The drawing, schedule or specification reference.
“Plasterboard lining” may not be enough detail. You may also need to record the board type and thickness, number of layers, frame depth, insulation, height and fire or acoustic requirements. State whether joints are taped and filled or fully skimmed.
Apply the same rule throughout the take-off. If small openings are not deducted, record the limit. If waste is included in the material quantity, show it separately from the installed amount. This helps prevent waste being counted twice.
4. Record assumptions, allowances and exclusions
Write assumptions down as soon as they arise. Common examples include missing dimensions, uncertain levels or depths, unconfirmed ground conditions, unclear demolition, restricted access, storage and lifting arrangements, working-hour limits, protection requirements and design still to be developed.
Separate measured quantities from allowances. An allowance is an estimated amount used where the information is not complete. Give it a description, a basis and a reason. If specialist design is needed, say whether the price includes design responsibility, coordination and production information.
Exclusions should be specific. Depending on the package, they might cover design and calculations, temporary works, scaffolding or powered access, general site facilities, hazardous-material removal, out-of-hours work, testing and certification, work connected with other trades, abnormal ground or changes made after the pricing information date.
Do not use exclusions to conceal a missing item. If something is needed but cannot yet be measured, list it as an allowance, risk or query. Seek clarification before submitting a firm price.
5. Complete the commercial check
Before issuing the price, check every scope item has a quantity, unit, description and source. Compare the take-off with plans, elevations, sections, schedules and specifications. Look for missed rooms, repeated areas, returns, vertical work, access needs and trade interfaces.
Then check the commercial requirements. Confirm the return format, programme, subcontract conditions, payment terms, retention, insurance, site attendance duties and price validity period. These may not change the quantity, but they can change the cost and the risk you accept.
You may be able to measure a small, familiar package yourself when the information is coordinated and you have time for an independent check. A professional take-off may be useful for a large or frequently revised package, incomplete information, overlapping trades, complex phasing or a quick tender return.
A professional take-off cannot remove uncertainty from unfinished design information. It should make that uncertainty clear by separating measured work, assumptions, exclusions, risks and queries. Agree the measurement basis, level of detail and checking process before the work starts. If you are unsure which packages need a measured take-off, tell us about your project.
The final test is simple: could another estimator understand what you measured, why you measured it that way and what your price does not include? If not, the take-off is not ready to support a firm subcontract price.
