Deciding the settlement of tower-crane base, erection-and-dismantling and off-site transport charges (including where the tower crane was never installed): three charges kept in separate accounts + the "charge as actually incurred" principle + recomputation of preliminaries at final account under BOQ pricing

Topic Positioning

This card answers how the tower-crane base, erection-and-dismantling and off-site transport charges are separately settled at final account - especially the basis where the tower crane was never installed (or not installed as planned). Method: first split the three charges of different natures into separate accounts, then apply the "charge as actually incurred" principle to each, and finally recompute the preliminaries under the BOQ pricing rules.

Core Conclusions

1. First, three separate accounts (prevailing quota positions)

1. Tower-crane base (fixed or rail-mounted) - one of the "separately computed charges" of plant machine-shift costs, in neither the machine-shift rate nor the erection-and-dismantling charge. Shandong Rules for Compiling Plant Machine-Shift Costs: "separately computed charges cover tower-crane and builder's-hoist bases and the erection / dismantling and off-site transport of certain plant"; "the fixed base applies to tower-crane or builder's-hoist bases of concrete volume within 10 m3". Hunan 2024 consumption standard appendix: "the erection-and-dismantling charge is a one-off charge for erection and dismantling and excludes tower-crane and builder's-hoist bases, ground improvement and other fixed bases; fixed bases follow the corresponding items of the building works consumption standard, and demolition, where required, is computed separately." Jiangsu building and decoration quota tower-crane base item notes: "1. This table is for budget compiling only; at final account adjust to site conditions. 2. For eaves over 20 m, add 0.04 t of tie steel per additional 10 m. 3. Where the base needs piling under it or floor strengthening, the cost follows the construction method statement." Shaanxi new consumption quota: "the fixed base applies to tower-crane bases of concrete volume within 60 m3; beyond that, compute the concrete, formwork and rebar separately ... where piling is required under the fixed base, the piling cost is computed separately." -> The base is a physical work, measured on the physical quantity actually completed (built, physical and accepted = chargeable; not built = not chargeable).

2. Erection-and-dismantling charge - a one-off charge for erection and dismantling, including trial running after erection, excluding ground improvement. Shandong: "the erection-and-dismantling charge is one-off for erection and dismantling and excludes ground improvement"; "trial running after erection is included". Hunan: "one-off for erection and dismantling ...". The charge counts per actual set-ups (machine occasions); no erection or dismantling, no charge.

3. Off-site transport charge (mobilisation / demobilisation) - per set-up; Jiangsu plant machine-shift reference table: "large plant at one project location generally computes off-site transport (mobilisation / demobilisation) and erection / dismantling only once". Distance bases differ: Shandong "off-site transport covers plant mobilisation within 30 km"; Hunan within 25 km.

4. Piling under the base, ground improvement, floor strengthening - outside the base items; absent contract agreement otherwise, charged per the construction method statement or actual occurrence (Shandong item 6; Jiangsu base note 3; Shaanxi item 3).

2. Measurement: budgets by rule, settlement by site Shaanxi quota: "plant erection-and-dismantling counts per machine occasion ... 3. tower cranes count set-ups per unit work or per 6000 m2 of single-storey floor area per crane" - a budget-time estimating rule. The Jiangsu base note expressly says "for budget compiling only; at final account adjust to site conditions": settlement therefore follows the actual set-ups and the actual base as built, not the budgeted estimate.

3. BOQ-priced works: final account charges only the preliminaries "contained in the completed works" GB/T 50500-2024 clause 10.2.7: "the preliminaries computed under clause 10.2.5 and the main contractor's attendance computed under 10.2.6 serve only to compute and pay interim (process) settlement prices and are not a basis for the final account price. At final account of the whole contract works, the preliminaries and main contractor's attendance shall be recomputed per the contract and adjusted up or down per the confirmed result." Clause 10.3.3: "at final account the parties shall recompute the preliminaries and main contractor's attendance listed in the interim settlement documents, complying: 1 the preliminaries shall be computed per section 7.3 and chapter 8 as the full preliminaries contained in the completed works, including adjustments to the statutory work-safety levy. Preliminaries listed in interim settlements do not bind the final account." -> A tower crane never installed is not a preliminary "contained in the completed works": the listed base / erection / transport charges are reduced accordingly; interim payments already made trues up on recomputation.

4. Review basis and the capped-pricing red line T/ZBD 100.5-2023 Guidance for Settlement Review Practice, clause 3.1.6: for fixed-unit-rate contracts, preliminaries adjust per the items and pricing methods agreed in the contract; absent or unclear agreement - (1) preliminaries tied to divisional work items (formwork, scaffolding etc.) move with those quantities and price at the agreed all-in rates; (2) competitive stand-alone preliminaries (slope protection, dewatering, retention, temporary roads, hoarding etc.) follow the contract or the original tender; (3) project-wide percentage- or scheme-based preliminaries (statutory HSE provisions, vertical transport, superheight increment etc.) compute or adjust per State rules and the contract on the tendered base and rates. And the preliminaries cap: GB/T 50500-2024 clause 3.3.7 - "the preliminary-work method statement in the contractor's tender is deemed reasonable, feasible and matching actual construction; the preliminaries are priced on a capped basis, and the contractor bears the risk of increases caused by its own method changes. Except for variations, works not fully foreseen or detailed under provisional sums, and employer-caused extended use, removal and re-provision of preliminaries, which adjust under chapter 8, no other adjustment is made." That is, the contractor's unilateral method change (fewer or no tower cranes) is no basis for increasing or retaining preliminaries; conversely, preliminaries for what never occurred are reduced at settlement on the facts.

Applicability Boundaries

• Splitting the three accounts and charging nothing for what did not occur presupposes the contract is silent on the preliminaries; express contract agreement prevails.
• Quota parameters differ by province and follow the project location's current quota; those cited are examples: fixed-base concrete caps (10 m3 / 60 m3), transport distance (30 km / 25 km), rail-laying arc factor 1.15, self-climbing tower-crane erection charges banded by crane height (45 m / 50 m) plus 10% per additional 10 m, set-ups per 6000 m2 per crane.
• GB/T 50500-2024 is a recommended standard; contract agreement prevails; projects without interim (process) settlement follow the contract's settlement terms.
• This card summarises the settlement decision basis; it does not replace the project's contract clauses and quota item verification, and contains no monetary computation.

Further Reading

• GB/T 50500-2024 Standard for Pricing of Works on a Bill of Quantities Basis, clause 3.3.7 (preliminaries cap and exceptions), clauses 10.2.7 and 10.3.3 (recomputing preliminaries at final account), section 7.3 and chapter 8 (measurement exceptions and price adjustment).
• T/ZBD 100.5-2023 Guidance for Settlement Review Practice, clause 3.1.6 (fixed-unit-rate review: adjustment of preliminaries and other charges).
• Local plant machine-shift quota notes: Shandong Rules for Compiling Plant Machine-Shift Costs, "separately computed charges"; Hunan 2024 consumption standard appendix (plant machine-shifts); Jiangsu reference table of plant and machine-shift costs (definitions of erection / dismantling and off-site transport; "once per project location"); Jiangsu building and decoration quota tower-crane base item notes; Shaanxi new consumption quota (measurement of large-plant mobilisation and erection, superheight).