I-COST
Why the Lowest Quote Is Often the Most Expensive
Procurement is where theoretical estimates meet commercial reality. In construction buying, selecting a supplier solely on the basis of the lowest headline price is one of the quickest ways to trigger cost overruns. A quote that appears £2,000 cheaper on paper frequently turns out to be £5,000 more expensive once transport surcharges, unpalleted deliveries, missing fixing components, and strict payment terms are accounted for.
Professional quantity surveyors and buyers use structured like-for-like comparison techniques to normalise supplier bids before placing commitment orders.
The Quotation Normalisation Matrix
When quotes arrive from competing builders merchants, specialist manufacturers, or trade subcontractors, evaluate them against these critical criteria:
- Specification Compliance: Does the quoted product meet the exact British Standard, fire rating, thermal performance, or structural grade specified by the client's architect?
- Carriage & Offloading: Is transport included? Is delivery kerbside via articulated lorry, or does it include a mechanical offload (Hiab / crane) suitable for restricted site access?
- Minimum Order Quantities (MOQ): Are prices predicated on full truckload deliveries? What are the penalties for split or call-off deliveries?
- Price Validity Window: How long is the quoted rate fixed? Does it cover the planned site installation dates, or does it expire before the project starts?
- Lead Times & Delivery Guarantees: Can the supplier meet the programme schedule, or will an 8-week lead time delay subsequent trades?
Worked Example: Structural Timber Framing Package Comparison
Consider an actual evaluation of three supplier quotations for a £75,000 structural timber and sheet material package for a residential development:
| Evaluation Metric | Supplier A (National Merchant) | Supplier B (Regional Timber Specialist) | Supplier C (Online Broker) |
|---|---|---|---|
| Headline Quoted Price | £74,200 | £76,800 | £71,500 (Lowest) |
| Specification Check | C24 treated timber fully compliant | C24 treated timber fully compliant | Supplied C16 timber on joists (Non-compliant) |
| Delivery & Offloading | Free Hiab delivery to plot | Free offload on orders > £2,500 | £350 per drop; driver only (Contractor offloads) |
| Price Hold Period | 60 days fixed | 90 days fixed to programme | 14 days only; subject to market revision |
| Lead Time | 5 working days | 3 working days | 15 to 20 working days |
| Effective Normalised Cost | £74,200 (Best Value) | £76,800 | £79,800 (After compliance & transport) |
Although Supplier C presented the lowest initial bid (£71,500), correcting their non-compliant timber grade, adding eight required delivery charges (£2,800), and hiring forklift plant to offload materials on site raised their true cost to almost £80,000. Supplier A represented the genuine lowest compliant bid.
Best Practices for Construction Procurement
- Issue Standard RFQ Schedules: Provide suppliers with a standard schedule of quantities and specific commercial terms rather than asking for general price lists.
- Request Fixed Price Periods: Always stipulate the required delivery window in the RFQ so suppliers build inflation allowances into their quotes upfront.
- Retain Central Quotation Records: Store all quotations in a central, accessible digital database so future estimates can leverage pre-negotiated commercial rates.
Key Takeaways
- Protect Margin from Day One: Margin leakage occurs incrementally; establish committed cost controls before placing orders.
- Enforce Written Protocols: Verbal site requests carry 100% contractor risk. Require written confirmations of verbal instructions (CAIs) immediately.
- Bridge the Estimating-Buying Gap: Ensure the tender estimate baseline directly governs purchase order authorization and live project tracking.
Explore how I-Cost supports construction commercial management
I-Cost brings your client's BOQ, estimate, supplier quotations, purchase orders, mobile site timesheets, and whole life carbon into one connected system for UK contractors, calculating live forecast margin from day one.
Frequently Asked Questions
What is like-for-like quotation comparison?
Like-for-like comparison is the practice of adjusting received supplier quotations to account for differing specifications, delivery terms, payment conditions, and hidden surcharges, ensuring true total procurement costs are evaluated rather than just headline unit rates.
What hidden fees frequently appear in merchant quotes?
Common surcharges include part-load delivery penalties, crane offload fees (hiab), pallet return deposits, waiting time charges on site, and minimum order administration fees.
How long should supplier price validity typically last?
Standard merchant quotes historically held prices for 30 to 60 days. In volatile market conditions, some suppliers limit validity to 14 days or reserve the right to apply price-in-effect adjustments upon delivery.
