Super-height inefficiency (super-height fee) in installation works: Beijing DB11/T 2382-2024's 6m starting threshold and coefficient system, compared with the '20m' basis in civil-works costing (Jiangsu/Hunan)

Topic Positioning

The costing basis for the installation 'super-height fee' (standard name: 'super-height construction labour inefficiency' / 'super-height inefficiency'): Beijing's current standard adopts a '6m starting threshold + coefficient system, labour only', whereas the '20m threshold, calculated on labour cost (or labour cost + plant cost)' commonly found in building/decoration systems is a different basis. Before applying either, confirm the discipline system and the quota edition concerned, so as to avoid applying it across systems.

Core Conclusions

1. Beijing installation basis (DB11/T 2382-2024, clause 6.1.2, original text): 'Where the installation height of equipment or materials exceeds 6m, the labour inefficiency caused by super-height working shall be calculated by multiplying the labour consumption of the relevant item by the super-height inefficiency increase coefficient, which shall comply with Table 6.1.2.' Table 6.1.2: operating height up to 10m — coefficient 0.10; up to 30m — 0.20; up to 50m — 0.50. That is: no adjustment at ≤6m; >6m and ≤10m × 0.10; >10m and ≤30m × 0.20; >30m and ≤50m × 0.50. The base of adjustment is 'the labour consumption of the relevant item'; material and plant consumption are not multiplied by the coefficient.
2. Cost attribution (GB/T 50856-2024, clause 3.0.12, original text): 'Operating-height increases under this standard are included in the billed BOQ items for work sections.' — super-height inefficiency is not billed separately as a preliminary item; each BOQ item is classified according to the installation height of its equipment/materials, and the additional labour consumption is included in labour cost under that BOQ item; where an audit trail is required, a separate 'super-height inefficiency additional labour' line may be shown within the labour/material/plant breakdown of that BOQ item, without changing the cost attribution.
3. Computation: additional labour consumption for super-height inefficiency = original labour consumption × coefficient; adjusted labour consumption = original labour consumption × (1 + coefficient). Examples: original labour consumption 10 workdays, installation height 24m (band up to 30m) → 10 × (1 + 0.20) = 12 workdays; installation height 45m (band up to 50m) → 10 × (1 + 0.50) = 15 workdays.
4. Basis analysis ('20m' belongs to the building/decoration system, not the Beijing installation basis):

• Jiangsu 2026 edition consumption standard for building and decoration works: 'Where the structural height from the designed external ground level to the floor level of a storey exceeds 20m, or the number of storeys exceeds 6, super-height inefficiency shall be calculated'; meeting either the 'height' indicator or the 'storey' indicator is sufficient to apply that sub-item; the calculation base is the labour cost of the portion above the threshold; it excludes vertical transport, component transport and installation works, comprehensive scaffolding, lift-shaft scaffolding, chimney and water-tower scaffolding, and on-site precast concrete and steel component fabrication items.
• Hunan 2025 edition consumption standard for building and decoration works: 'Where the eaves height of the building exceeds 20m, the super-height increase fee shall be calculated in accordance with this consumption standard'; Chapters 11 to 17 calculate the super-height increase fee by multiplying labour cost and plant cost by a coefficient, while other chapters calculate it on the gross floor area (GFA) above the 20m eaves height; where a building has different eaves heights, it shall be divided vertically according to the different eaves heights, with GFA calculated separately and items applied separately.

Applicable Boundaries

• Items 1–3 above apply only to projects executed under Beijing DB11/T 2382-2024, Consumption Standard for Construction Works, general installation works; the coefficient clause is set out in Chapter 6.1 'Mechanical Equipment Installation Works', and when applying other discipline volumes (electrical equipment installation, water supply/drainage/heating/gas, information and communication technology, painting and anti-corrosion/insulation, etc.), the citation basis in that volume's chapter notes shall be checked.
• Table 6.1.2 tops out at 'up to 50m'; cases where the installation height exceeds 50m are not covered by this table and the basis must be confirmed separately.
• Super-height inefficiency adjusts labour consumption only; material and plant consumption are not adjusted.
• The calculation bases and coefficients in Jiangsu and Hunan are not transferable across regions or disciplines; where a project contract locks an older pricing basis (e.g. the 2021 edition), the volume notes of the edition stipulated in the contract prevail.
• Where a basis document states 'above 20m, calculated on labour cost (or labour cost + plant cost)', this generally belongs to the building/decoration or another quota system; the system to which the document belongs must be verified first and it cannot be applied directly to installation works.

Further Reading

• DB11/T 2382-2024, Consumption Standard for Construction Works, general installation works, Chapter 6.1 'Mechanical Equipment Installation Works', clauses 6.1.1–6.1.2 and Table 6.1.2 (super-height inefficiency increase coefficient table).
• GB/T 50856-2024, Standard for Measurement of General Installation Works, clause 3.0.12 and its commentary (cost attribution of operating-height increases).
• Jiangsu 2026 edition consumption standard for building and decoration works, 'Building super-height inefficiency' chapter notes and method of measurement.
• Hunan 2025 edition consumption standard for building and decoration works, 'Chapter 21 Super-height increase fee' notes and method of measurement.