The decision in one minute
Ask each shortlisted contractor to price the same issue of the drawings and specifications. Preserve their original offers. Record every difference in a separate comparison, then obtain written clarifications. Keep unresolved items visible rather than assigning them a zero cost.
This is not a reason to reject the lowest price. Once the offers are genuinely comparable, the lower price may be the better commercial proposal. The purpose is to find out whether the difference comes from efficiency, a different solution, a different allocation of risk or missing work.
Two quotations, one residence, different promises
Consider a residence with a pool, landscaped terraces and a separate technical room. Both contractors receive the same architectural plans. Contractor A returns a short quotation. Contractor B submits a longer bill of quantities, or BOQ: a document that breaks the work into described items, quantities, units and prices.
The following comparison is illustrative. It is not a record of a DALLEAU tender or a statement about Bali market prices.
| Item | Offer A | Offer B | What must be resolved |
|---|---|---|---|
| External drainage | “By owner” | Pipework and chambers included | Which drawings, outlets and connection point are included? |
| Bathroom finishes | Tile supply allowance | Named tile, adhesive and installation | Do both cover the same area and installed assembly? |
| Air conditioning | Equipment only | Equipment, installation and controls | Who provides drains, power, commissioning and access? |
| Waterproofing | “Waterproofing included” | Specified areas, preparation and testing | What is the system, who accepts the substrate, and who pays for a retest? |
| Temporary site facilities | Not mentioned | Temporary power, protection and waste removal | Is the first offer silent or genuinely inclusive? |
| Handover | “Project completion” | Listed drawings, manuals and training | Which deliverables are required before final release? |
Nothing in this table proves that B is the better contractor. It shows that comparing their totals immediately would answer the wrong question.
“By owner” means someone else must procure the work. “Not mentioned” means the allocation is unresolved. Neither means the work will be free.
1. Freeze what everyone is pricing
Send one dated pricing package. Identify the drawing revisions, specification, relevant surveys, schedule assumptions and allocation of design responsibilities. Record whether the contractor must design an element, construct an already coordinated design, or price an allowance pending a decision.
If a drawing changes during the tender, issue that change to every bidder and request a revised return. Do not let one quotation include the revised pool plant while another still prices the earlier layout.
The RICS NRM framework distinguishes cost planning from detailed measurement for building works. Its purpose includes a consistent basis for cost information and pricing documents. That is a useful methodological reference here, not a claim that a private Bali contract automatically adopts a UK measurement standard. [1]
2. Compare quantities and units before unit rates
A rate for one square metre is not comparable until the measured work is comparable.
For a tiled shower, ask what area is measured and what the item includes: substrate preparation, screed, falls, waterproofing, adhesive, tile, trims, movement joints and installation. Confirm whether a waste allowance sits in the quantity, the material rate or another line. Otherwise the same allowance can be omitted or counted twice.
A difference in quantity may be a measurement error, a scope difference or a legitimate different interpretation. Ask for the take-off and measurement basis. Do not silently replace a contractor’s quantity and call the adjusted number an agreed price.
Keep three figures distinct: the original offer, the comparison adjustment and the contractor’s subsequently confirmed price.
3. Read the exclusions as a second quotation
Review site clearance, unsuitable ground, disposal, access, temporary services, drainage, utility connections, specialist attendance, testing and handover. Not every item belongs in every contractor’s package, but each necessary item needs an owner, a scope and a budget location.
For example, excluding a final utility connection can be entirely sensible if a separate provider is already appointed. It becomes a budget gap when nobody has priced it, the connection route is unknown and the owner assumes that “turnkey” includes everything.
The useful question is not “Is this included?” alone. Ask: “Included by whom, to which boundary, against which document?”
4. Separate fixed prices from allowances
An allowance is money reserved for work or a selection that has not yet been fully defined. It is not the same as a confirmed price for a named installed product.
Suppose both offers contain a bathroom allowance. One may cover tile supply only; the other may include installation. The heading is the same, but the commitment is different. Write down what the allowance includes, how the eventual selection changes the price, what margin or attendance may be added, and who approves that change.
Avoid adding a new full allowance on top of an existing one. The comparison needs the adjustment between them, with its basis recorded.
Keep owner contingency separate. It is a reserve for uncertainty, not a device for hiding omissions or making an incomplete tender look complete.
5. Compare the assembled result, not the product name
A named waterproofing product does not describe the complete waterproofing package. A named air-conditioning unit does not describe the whole cooling installation.
Check the interfaces: preparation, supports, penetrations, power, drainage, controls, access, tests and responsibilities. In a bathroom, coordinating the shower-glass profile before tiling is a different delivery method from cutting a channel into newly installed tile. Our Delivery Partners page illustrates that sequencing question.
The contractor’s price should correspond to the coordinated method actually selected for the project. A cheaper substitution should be assessed for specification, compatibility, lead time and maintenance, not accepted solely because the initial price falls.
6. Put tax and commercial conditions on the same basis
Record whether each offer includes the applicable taxes and what treatment its supplier proposes. Have the relevant tax adviser confirm the project-specific position. Do not add a generic percentage to every quotation and assume the comparison is complete.
Then compare validity, currency, escalation provisions, mobilisation, payment milestones, retention where agreed, warranties and programme. Two equal totals can carry very different cash-flow and completion risks.
A payment request labelled “70% complete” is not enough to understand what is being paid for. Identify the contractual milestone, the work covered, the inspection record and unresolved items. This is why payment evidence belongs alongside the price comparison.
7. Ask better clarification questions
Replace “Please give us your best price” with a short, numbered clarification schedule.
For the drainage example: “Please confirm whether the terrace drains, pipework, inspection chambers and connection to the approved outfall shown on revision X are included. Identify exclusions and the corresponding price and programme effect.”
For handover: “Please identify the as-built information, equipment schedules, test records and staff training included in your offer, and the payment milestone against which they are due.”
Give the contractor space to propose a better method. Record the alternative separately from the conforming offer so that an improvement is not confused with an omission.
What the comparison should show
The final comparison needs the original total, confirmed additions or deductions, unresolved items and the resulting comparable total. It also needs a separate decision on technical acceptability, resources, programme and commercial terms.
An unresolved exclusion must not disappear into a spreadsheet formula. Our worksheet leaves the result as Not comparable while required information is missing. It does not award a contract or imply that the cheaper resolved offer must win.
A good conclusion might be: “A remains less expensive on the agreed basis. Its drainage exclusion is now priced, the technical team has accepted the proposed system, and the programme and payment terms are recorded.” That is a decision supported by a file, rather than a preference supported by a headline number.
Where DALLEAU fits
Within the appointed mandate, DALLEAU coordinates the owner’s pricing basis, consolidates questions and keeps decisions and clarifications connected. The appointed designer, engineer, cost consultant and contractor retain their own responsibilities. The owner should see both the commercial comparison and the reasons for the recommendation.
Read how the mandate works or Talk to François about the decision facing your project.
References
[1] RICS New Rules of Measurement. Methodological reference for measurement and cost information. The examples and worksheet above are DALLEAU’s illustrative owner-side explanation, not RICS forms or a prescribed Indonesian contract.
[2] DALLEAU Delivery Partners. Public procurement, communication and interface-control method.
Continue with the next decision
The €150,000 villa Reality Check explains why a sale price and a construction quotation require different complete-cost comparisons.