Cost Intelligence · Calibration Architecture
Three-Way Cost Calibration
The construction model is now being stress-tested against three independent evidence systems: bottom-up engineering, government/tender evidence, and developer-residual market evidence. They are compared, not averaged.
01 · Engineering
Quantity × rate
Geometry, assemblies, materials, labour, logistics and project economics. No hidden ₹/sq.ft shortcut.
02 · Tender / SOR
Observed work
Government schedules and accepted tender observations provide external assembly/item reference points.
03 · Developer residual
House − land
Matched market evidence estimates the building component, then applies the documented 15% selling-price margin assumption.
First engineering finding: the calibration run exposed and corrected a unit-conversion defect in the POC perimeter geometry. The footprint was in ft² while perimeter was being interpreted as metres. The core now converts footprint to m² before deriving perimeter. All four calibration cases below therefore use the corrected engine.
Four canonical houses — live engine output
Loading the current pricing core…
Component variance matrix
Only like-for-like or explicitly qualified comparisons are shown. A tender item with materially different scope is not treated as a production rate merely because its unit is the same.
| Component | Engineering rate | Tender comparator | Market comparator | Variance / interpretation | Evidence status |
|---|---|---|---|---|---|
| PCC / foundation concrete | ₹3,500/m³ | SECL Manikpur: median ₹3,500/m³, PCC 1:3:6 | — | Nominal rate alignment; verify mix, tax, carriage and scope before authorization. | research calibration |
| M25 structural concrete | Raipur ₹5,229/m³; Indore ₹5,415/m³ RMC proxy | SECL Manikpur: median ₹2,591/m³; design-mix item, scope differs. SECL Raigarh: ₹6,602.20/m³ to plinth, different mix/scope. | Raipur M25 RMC research anchor ₹5,229/m³; Indore ₹5,415/m³ | Not a clean tender variance: RMC supply and installed tender work have different inclusions/exclusions. | scope mismatch |
| Fe500D reinforcement | ₹78/kg = ₹58 material + ₹20 provisional fixing | SECL Manikpur: median ₹59.68/kg installed reinforcement work | Fe500D research observations around ₹58/kg | Engineering composite is about 31% above the tender median; likely scope/component-definition issue, not a justified production uplift. | investigate |
| RCC formwork | ₹195/m² | SECL Manikpur foundation formwork median ₹195/m² | Raipur research observation ₹297/m² for column formwork | Foundation comparator aligns exactly; column/suspended-floor evidence is not equivalent and suggests scope/geometry segmentation is needed. | partial match |
| 230 mm brick masonry | Derived from cement/sand/labour + provisional base | No validated like-for-like comparator currently loaded | No sufficiently equivalent current installed-rate observation loaded | Do not manufacture a variance. Evidence gap remains. | evidence gap |
| Cement plaster | 12 mm / 15 mm derived from CPWD coefficients + regional inputs | Coefficient basis available; no current equivalent installed tender rate loaded | — | Input calibration is possible, but complete installed-rate validation is still missing. | provisional |
| Flooring | Tile ₹850/m²; stone ~₹1,077–1,110/m² after premium factor | — | Kota/stone research observations are not equivalent to the complete installed system | Material-only or differently scoped flooring observations must not be used as installed-system variance. | scope gap |
| Electrical points | Raipur ₹781.70/point; Indore ₹804.20/point | CPWD DSR 2025 standard point ₹1,417; modular ₹1,440 | Indore concealed-point research range ₹987–1,380 | Engineering rate is below external installed-point references; scope, point definition, accessories and labour need reconciliation. | investigate |
| Bathroom package | Raipur ₹74,245/bath; Indore ₹75,008/bath | — | Only individual sanitary-item evidence currently loaded | Package-level market validation is absent; individual basin prices cannot calibrate the package. | evidence gap |
| Terrace waterproofing | ₹874/m² named-system provisional build | — | Dr Fixit consumption evidence exists, but complete installed regional rate does not | Consumption is evidenced; installed cost remains provisional. | provisional |
Developer-residual building-level references
| Market evidence | Residual reference after 15% selling-price margin | Interpretation |
|---|---|---|
| Raipur · VIP City | ₹2,487.81/carpet ft² | Class B calibration evidence; matched project/plot/house relationship with carpet inferred. |
| Raipur · Aurum historical candidate | ₹2,040/salable ft² | Class B candidate only; historical listings exist, but exact parcel/configuration pairing is not proven. |
| Indore · Victoria City | ₹2,002.22–2,408.33/carpet ft² | Class B; portal area variants retained rather than collapsed. |
| Indore · Omaxe City-1 | ₹3,740–4,165/carpet ft² | Class A matched evidence but explicitly premium/atypical because of exceptional amenities and built-up intensity. |
What the first pass tells us
We do not yet have a validated construction rate. The useful output is the list of things that must be fixed. The corrected geometry substantially changes masonry/plaster/opening quantities; reinforcement remains a major reconciliation item; RCC tender evidence is scope-divergent; and several finish/service packages still lack complete installed-rate evidence.
- Keep the perimeter unit fix in the production branch.
- Reinforcement: the ₹20/kg add-on is now explicitly tagged as provisional. External evidence shows ₹59.68/kg in the local SECL calibration set and ₹76.52/kg in a 2024–25 Fe500D SOR benchmark, while 2026 government documents confirm that reinforcement assemblies can include cutting, bending, binding, spacers and handling. The next gate is local delivered material + installed-work decomposition; no rate is promoted yet.
- Formwork: the one-pass review confirms materially different local observations — foundation ₹195/m² at Manikpur, ₹273.60/m² at Raigarh, beam/plinth/lintel ₹499.45/m² and column ₹649.85/m². We are not promoting these into production because the local evidence is not yet specification/reuse-cycle/tax normalised. The POC therefore retains ₹195/m² as a provisional foundation-calibrated proxy rather than pretending it is a universal validated rate.
- Build a validated masonry assembly before allowing masonry into production calculations.
- Build installed-rate evidence packs for flooring, electrical and bathroom packages.
- Rerun all four houses after those reconciliations and compare the engineering totals with residual evidence only at the building level.
Production rule: no calibration agreement by itself authorizes production. The production chain remains physical quantity → evidenced component/assembly rate → explicit project additions → auditable total.
Formwork audit: data/cost-intelligence/formwork-assembly-audit-mp-cg-2026-09.json. Reinforcement audit: data/cost-intelligence/reinforcement-assembly-audit-mp-cg-2026-09.json. Live calculations use cost-intelligence/poc-pricing-core.js. Framework: data/cost-intelligence/three-way-calibration-framework-2026-09.json. External figures remain calibration/research evidence.