Quantity comparison, Tender issue to Contract issue
Structural, architectural and finishes quantities taken from the two issued models, aligned by level and element category, and compared line by line.
1Result at a glance
1,620 lines are unchanged within the rounding stated in section 5. Increased, decreased and new lines are listed in sheets 2 to 4 of the full report.
2Principal quantity changes
Twelve lines with the largest effect. Difference is Contract less Tender.
| Ref | Item | Unit | Tender | Contract | Difference | % | Cause | Effect |
|---|---|---|---|---|---|---|---|---|
| Q-0412 | Concrete, floor slabs L1 to L4 | m³ | 1,184 | 1,421 | +237 | +20.0 | Slab thickness 250 to 300 mm at L1 to L4 | Major |
| Q-0388 | Concrete, core walls L1 to L8 | m³ | 1,038 | 1,172 | +134 | +12.9 | Core wall 300 to 350 mm; second lift shaft added at grid E | Major |
| Q-0401 | Concrete, podium transfer slab | m³ | 612 | 668 | +56 | +9.2 | Transfer slab extended over the ramp bay, grids C to D | Medium |
| Q-0436 | Concrete, columns L9 to L14 | m³ | 486 | 471 | −15 | −3.1 | Column 600 × 600 to 500 × 700 at L9 to L14 | Minor |
| Q-0520 | Formwork, slab soffits | m² | 14,220 | 14,655 | +435 | +3.1 | Balcony slabs widened at L1 to L4, north face | Minor |
| Q-0533 | Formwork, core walls | m² | 9,870 | 10,310 | +440 | +4.5 | Follows the core wall change and the added lift shaft | Medium |
| Q-0611 | Reinforcement, slabs | t | 196.4 | 241.9 | +45.5 | +23.2 | Thicker slabs L1 to L4; top mesh T12 to T16 at columns | Major |
| Q-0624 | Reinforcement, columns | t | 88.2 | 85.9 | −2.3 | −2.6 | Column size reduction at L9 to L14 | Minor |
| Q-0810 | Blockwork, 200 mm internal | m² | 11,460 | 10,985 | −475 | −4.1 | Corridor partitions changed to drywall at L5 to L14 | Medium |
| Q-0814 | Blockwork, 100 mm internal | m² | 6,210 | 6,585 | +375 | +6.0 | Bathroom layout revised in type B apartments | Medium |
| Q-1102 | Floor finish, porcelain 600 × 600 | m² | 18,340 | 18,920 | +580 | +3.2 | Living rooms extended onto balconies at L1 to L4 | Minor |
| Q-1340 | Doors, single leaf internal | nr | 842 | 868 | +26 | +3.1 | Storage rooms added in type B apartments, L5 to L14 | Minor |
| Concrete, all categories | 8,964 | 9,376 | +412 | +4.6 | Four lines above account for the whole net change | |||
Effect grades the line by its share of the category total and by whether other trades follow the change.
3Concrete volume per level
Tender against Contract, m³ per level. Slab, walls and columns rising from each level.
Tender issue Contract issue, increased Contract issue, decreased
The podium includes the transfer slab. Differences above the bars are in m³.
4Traced to elements
Elements behind the net concrete change
- SLB-L1-001 Floor slab L1, grids A to D · 250 to 300 mm +61.3 m³ · +11.7 t rebar
- SLB-L2-001 Floor slab L2, grids A to D · 250 to 300 mm +60.8 m³ · +11.6 t rebar
- WAL-CORE-E-03 Core wall, grid E, L1 to L8 · 300 to 350 mm, lift shaft added +134.2 m³ · +440 m² formwork
- SLB-P0-TR-002 Transfer slab, podium, grids C to D · extended over ramp bay +56.0 m³ · +38 m² soffit
- COL-L9-C4 + 11 alike Columns L9 to L14 · 600 × 600 to 500 × 700 −15.1 m³ · −2.3 t rebar
Element ids are those carried in the issued models. Slabs L3 and L4 and the remaining column ids follow in sheet 5. Contributions are rounded to 0.1 m³.
Evidence. Section at L2, grid B
Finished floor level held; the soffit drops 50 mm. The dashed line in the contract crop is the tender soffit. The circle marks the change the quantity line is traced to.
5Units and rounding
Volumes in m³ to the nearest unit in the summary and to 0.1 m³ per element; areas in m² to the nearest unit; reinforcement in tonnes to 0.1 t; doors and windows counted as number (nr). Percentages are of the Tender quantity. A line is reported as unchanged when the difference is within 0.5 % and within one unit. Quantities are measured from the issued models as modelled; they are not a bill of quantities and carry no waste, laps or deductions beyond those in the models.
The model-derived quantities module of NABU Compare is in development. The layout, categories and traced-element format shown here are those of the current build and may be refined before release.