How the building superheight increment cost is charged (building and decoration works, railway building works): triggered at 20 m eaves or 6 storeys, on labour cost (or labour plus plant cost) times a coefficient - and its distinction from the working-height allowance of installation works

Topic Positioning

How the "building superheight increment cost / superheight efficiency loss" is charged in building and decoration works (civil system) and railway building works - trigger conditions, computation base and banding - and how it differs from the "working-height allowance" of installation works.

Core Conclusions

1. Trigger conditions Where the building eaves height (outdoor design ground to eaves) exceeds 20 m, or the storeys exceed 6, the superheight increment cost / efficiency loss is chargeable; either the "height" or the "storeys" indicator suffices (stated expressly in the Jiangsu 2024 building and decoration consumption standard, 2026 edition in the source data). The Hunan 2024 building and decoration consumption standard (2025 edition in the source data) reads: "where the building eaves height exceeds 20 m, the superheight increment cost is computed under this consumption standard."

2. Different eaves heights Hunan standard: where a building has different eaves heights, split vertically by eaves height, compute floor areas separately, and apply the corresponding items by each eaves height.

3. Computation base and coefficient (varies by system)

• Hunan 2024 building and decoration consumption standard: for decoration chapters 11 to 17 the superheight increment cost is computed on the corresponding quantities above 20 m eaves height as "labour plus plant cost" times the superheight coefficient; for the other chapters, on the floor area above 20 m eaves height.
• Jiangsu 2024 building and decoration consumption standard (2026 edition in the source data): the efficiency-loss coefficient takes the "labour cost" of the parts with structural height from outdoor design ground to floor level above 20 m or storeys above 6 as its base; the superheight loss excludes vertical transport of building works, transport and erection of members, comprehensive scaffolding, lift-shaft frames, chimney and water-tower scaffolds, and fabrication of site-precast concrete and steel members.
• Railway building works (TB/T 10831-2024 Volume 10, chapter 1 civil works, section 8 vertical transport and superheight): the superheight increment cost is computed per 100 m2 with quota bands FY-1026 (eaves over 20 m up to 40 m), FY-1027 (over 40 m up to 60 m), FY-1028 (each additional 10 m of eaves). Work content includes reduced worker efficiency on shift, added time going up and down and for natural rest, time affected by vertical transport, plant efficiency loss induced by labour loss, and booster-pump machine-shifts where water pressure falls short.

4. Distinction from installation works (the key point) This card addresses "building superheight" (for the building as a whole / decoration works; base labour cost or labour plus plant cost; trigger 20 m or 6 storeys); the "operating-height increment / efficiency loss" of installation works triggers at 5 m or 6 m on the labour consumption of the corresponding items. Two separate systems - "above 20 m on labour plus plant cost" must not be carried over to installation works.

Applicability Boundaries

• Applies only to the building and decoration (civil) system and railway building works; general installation works, urban rail transit M&E works, railway information / power / rolling-stock works and similar installation volumes do not apply - charge under their operating-height provisions.
• Exclusions stipulated by the system (Jiangsu: vertical transport, member transport and erection, comprehensive scaffolding, lift-shaft frames, chimney and water-tower scaffolds, site-precast concrete and steel member fabrication) must not be charged twice.
• Trigger height, base and banding coefficients differ by region / system - follow the notes and measurement rules of the consumption standard or quota in use.

Further Reading

• Hunan 2024 building and decoration consumption standard, chapter 21 superheight increment cost (notes and measurement rules).
• Jiangsu 2024 building and decoration consumption standard (2026 edition in the source data), chapter 20 superheight efficiency loss of building works (notes and measurement rules).
• TB/T 10831-2024 Railway Works Budget Quota Manual, Volume 10 building works, chapter 1 civil works, section 8 vertical transport and superheight, item 2 building superheight increment cost (FY-1026 to FY-1028).
• Related: the installation-works position is on the companion card "charging the installation-works superheight efficiency loss (superheight cost)".