Reviewed for technical terminology, Turkish factory field reality and published EUR scope boundaries (not statutory engineering sign-off).
1. Normalising measurement units before looking at price
Turkish manufacturers quote in the unit that matches their production line: steel service centres and roll-formers often quote in €/tonne or €/kg, board factories quote in €/sheet or €/m², modular panel producers quote in €/m² of gross vs net cover width, and hardware factories quote per piece or per set. Before ranking any two offers, every line must be translated into the functional unit your project actually consumes.
Even when two suppliers use the same unit label, geometry shifts the arithmetic. In panel and cladding systems, one producer’s sandwich panel may provide 1,000 mm effective cover width while a second quotes gross coil feed width before joint overlap. In drywall and fibre cement boards, a 1,200 × 2,400 mm sheet (2.88 m²) at a fictional €15.60/sheet equals €5.42/m², whereas a 1,200 × 2,500 mm sheet (3.00 m²) at €16.00/sheet equals €5.33/m²—lower per nominal square metre, yet potentially higher in site cutting waste if your wall height is 2,400 mm.
In steel profiles, always check theoretical nominal weight versus coil-tolerance or scale weight. Two suppliers quoting identical €/kg rates will produce different invoice totals if Supplier A bills theoretical CAD mass at nominal 1.50 mm while Supplier B weighs bundles rolled from upper-tolerance coil or leaves punching slug weight inside the per-piece calculation.
| Product group | Typical supplier quote unit | Normalisation check required | Hidden layout / cost impact |
|---|---|---|---|
| Building boards | €/sheet or €/pallet | Convert exact length × width to nominal €/m² | Off-cut waste if sheet length mismatches stud/ceiling grid |
| Cold-formed steel | €/kg or €/tonne | Convert to €/linear metre and €/finished part at stated thickness | Base-metal vs coated thickness and theoretical vs scale billing |
| Roof & wall panels | €/m² | Check net installed cover width vs gross panel width | 4%–8% extra panel count if overlap losses are ignored |
| Doors & windows | €/unit or €/m² | Confirm frame depth, hardware set, glazing buildup & sill trims | Unpriced handles, cylinders, trickle vents or subframes |
| Insulation rolls/slabs | €/pack or €/m³ | Calculate €/m² at exact declared thickness & density/lambda | Compressed roll recovery vs rigid slab edge profile |
2. Aligning material grades, coatings and silent substitutions
Suppliers rarely reject an enquiry outright when they lack a requested grade; instead, many submit an offer based on their closest running stock and add a small footnote—or omit the grade code altogether. If your comparison spreadsheet records only “Quoted: Yes” and the unit price, silent technical downgrades slip straight into purchase orders.
Build dedicated columns in your comparison worksheet for Requested Spec vs Supplier Stated Spec across base material, thickness tolerance, coating/finish class and reference standard. Whenever a quotation leaves one of those fields blank or writes “standard quality”, mark the cell Unconfirmed — Clarification Required rather than assuming compliance with your RFQ.
Pay close attention to system completeness. A partition, façade or modular roof build-up relies on compatible fixings, EPDM washers, closures, jointing compounds, acoustic tapes and touch-up coatings. An offer that includes tested system accessories cannot be compared fairly with a bare-panel price that leaves your site team sourcing critical fixings locally at short notice.
3. Tooling, MOQs, packaging and Incoterms® handover locations
One-off and batch-dependent costs distort unit comparisons unless separated cleanly. Custom roll-forming sets, aluminium extrusion dies, embossing rollers, special RAL powder-coat setups and non-standard board edge setups may be quoted as a separate lump sum, amortised across the first batch or waived above a minimum tonnage. Separating Recurring Unit Price from One-Off Setup / Tooling lets you see both first-order cash impact and repeat-order economics.
Similarly, align delivery terms and geography. “EXW İstanbul” from a warehouse in Tuzla has very different domestic haulage and port/terminal charges compared with “EXW Kayseri” or “FCA Gemlik”. Confirm whether loading onto the buyer’s curtain-side trailer or stuffing into an ocean container (requiring ramps, dunnage or crane/stinger forklifts for 6–12 m bundles) is included in the factory’s quoted price.
Check quotation validity and raw-material indexing rules. Steel, aluminium, zinc and chemical-resin offers in Türkiye frequently carry short validity windows (often 3 to 7 days) or LME/coil-index clauses. Comparing an expired three-week-old quote against today’s offer creates a false benchmark.
- Separate recurring unit prices from one-off die, roll-tooling or small-batch colour surcharges.
- Verify exact handover district and whether container stuffing / flatbed side-loading is included.
- Check whether export pallets, ISPM-15 heat-treated timber, shrink hoods and corner guards are priced.
- Compare payment milestones, advance-payment percentages and lead-time start triggers (deposit vs drawing approval).
4. Checking supporting documents against the quoted product code
A quotation comparison is incomplete if it treats attached PDFs as automatic proof. When a supplier attaches an ISO certificate, a fire-reaction test report or a Declaration of Performance, verify four basic consistency points: (1) Is the company name on the document the same legal entity issuing the proforma invoice, or an unrelated group/third-party manufacturer? (2) Does the document cover the exact product model, thickness and density/coating quoted? (3) Are issue/validity dates current? (4) Is the document an actual product performance record or merely a general management-system certificate?
Document consistency checks do not replace review by your project engineer or notified body, but they immediately expose generic brochure attachments that do not match the offered configuration.
5. Running a structured clarification round before choosing a supplier
Once all offers are mapped into a side-by-side matrix, issue one written clarification list per shortlisted bidder so every missing grade, packing assumption or delivery detail is answered in writing and linked to a revised quotation reference. Never rely on unrecorded phone assurances for thickness, zinc mass or included accessories.
Under SerSourcing’s Quotation Comparison (SS-COMPARE, €290), we normalise up to three supplier quotations across up to 10 comparable line items, conduct one structured clarification round, separate supplier statements from verified document references and deliver an editable comparison matrix plus open-items list within a target of 3–5 business days. Additional quotations in the same comparison (€75 each) or extra blocks of up to 10 line items (€95 per block) can be added transparently when your tender is larger.