Deciding deductions for reserved bolt holes under the two measurement bases of concrete and formwork (including raft / foundation member classification, the 0.30 m2 hole threshold, and the equipment-foundation pocket exception)

Topic Positioning

Deciding whether "reserved bolt holes" - anchor-bolt pockets, tie / through-wall bolt holes, embedment pockets - are deducted under the two measurement bases of concrete quantities (volume m3) and formwork quantities (contact area m2); and stating the rules for rafts (flat slab / beam-slab raft foundations, full raft foundations) listed as foundation members, the 0.30 m2 individual-hole threshold, and the equipment-foundation pocket exception.

Core Conclusions

1. Concrete basis: bolts and bolt holes not deducted

GB/T 50854-2024 (quantity take-off standard for building and decoration works), Annex E (concrete and reinforced concrete works), E.7.1 "general notes on cast-in-place members", item 2, original:

"Cast-in-place reinforced concrete members do not deduct the volume of rebar, bolts, embedded parts or ducts within the member, but do deduct the volume of the structural steel of rigid skeletons." "Bolts" is expressly on the no-deduction list; item 1 of the same note also allows "concrete types" in item descriptions - ready-mixed, site-mixed, fair-faced, coloured, waterproof, acid-resistant, rubble and lightweight-aggregate concretes etc.

The Jiangsu building and decoration consumption standard (2026 edition in the source data) is more direct, listing "bolt holes" by name:

"Unless otherwise provided, concrete quantities are computed by volume at the dimensions shown. No deduction for the volume of rebar, cradles, bolt holes, bolts, embedded parts, or holes of 0.3 m2 or less within walls and slabs. The labour and materials added by leaving holes are charged no extra. 1. The volume of pile heads projecting into the foundation of a structure is not deducted. ..." (The same system on precast member fabrication: by volume at design-shown dimensions, no deduction for rebar, bolts, embedded parts or ducts, deducting the structural steel of rigid skeletons.)

Beijing DB11/T 2382-2024 Construction Works Consumption Quota Standard, clause 7.4.12 (network works; bridges and culverts the same):

"Cast-in-place concrete quantities are computed by volume at design-shown dimensions, with no deduction for embedded parts, rebar, through-wall bolts or holes of 0.30 m2 or less."

Shenzhen SJG 181.2-2024 Municipal Consumption Quota Standard, Volume 2 (bridges and culverts), clause 2.2.1, splits foundation-type and wall / slab bases:

"Blinding, foundations, pile caps, beams, piers and abutments of cast-in-place concrete are computed in cubic metres on the solid volume at design-shown dimensions (solid volume excluding the voids of beams and slabs), with no deduction for the volume of rebar, wire, ironmongery, reserved grouting ducts and bolts; cast-in-place concrete walls and slabs do not deduct hole volumes of individual area within 0.3 m2."

Railway TB/T 10831-2024 Railway Works Budget Quota Manual, Volume 10 building works, volume notes "measurement rules":

"(1) Cast-in-place concrete member quantities make no deduction for the volume of rebar, ironmongery and bolts. (2) Cast-in-place walls and slabs make no deduction for concrete volumes of holes within 0.30 m2." "(3) Foundations ... 2. Equipment foundations other than block types compute under the corresponding foundation, column, beam, wall and slab items. The volume of reserved pockets in equipment foundations is deducted." "(9) Precast concrete member quantities ... 1. Concrete quantities are computed on solid volume, deducting neither rebar, ironmongery, bolts nor holes of 300 x 300 or less, and deducting the voids of hollow slabs."

Conclusion: rafts (raft foundations, full raft foundations) are listed as foundation-type members; the foundation-type no-deduction list expressly covers bolts / bolt holes, and reserved bolt hole diameters usually sit far below 0.30 m2 - concrete quantities are not deducted.

2. Formwork basis: by contact area; individual holes 0.30 m2 or less not deducted, reveals not added

Formwork is computed in m2 on the contact area with the concrete member; overlapping at member junctions is not measured; holes follow the individual-hole 0.30 m2 threshold:

Hunan 2024 building and decoration consumption standard (2025 edition in the source data):

"3. Holes of individual area within 0.3 m2 in cast-in-place reinforced concrete walls and slabs are not deducted and the formwork to the hole reveals is not added; beyond 0.3 m2 they are deducted, and the reveal formwork area merges into the wall / slab formwork quantities."

The Jiangsu standard (2026 edition in the source data) on slab formwork:

"9. Cast-in-place slab and other-slab formwork deducts holes of individual area over 0.3 m2, the reveal area merging into the computation; holes of individual area 0.3 m2 or less are not deducted and their reveal area is likewise not computed." (Walls the same basis: door and window openings and holes over 0.3 m2 deducted with reveals merged; holes 0.3 m2 or less not deducted, reveals not computed; formwork at post-cast wall strips not deducted.)

Conclusion: reserved bolt holes of individual area generally far below 0.30 m2 - formwork quantities are not deducted and the reveal formwork area not added; the labour and materials added by leaving holes attract no extra charge under the quota basis.

3. Exceptions that change the conclusion

1. Individual hole area over 0.30 m2: concrete deducts the hole volume on the slab / wall basis; formwork deducts the hole area and merges the reveal formwork area into the wall / slab formwork quantities.
2. Equipment-foundation pockets: railway and like systems provide "the volume of reserved pockets in equipment foundations is deducted" - "ordinary-member bolt holes not deducted, equipment-foundation pockets deducted" are two distinct bases, never to be mixed.
3. Configuration / boundary rules changing the member class: e.g. a strip foundation whose rib height exceeds 4 times the rib width computes its bottom slab as a flat strip foundation and the part above as a wall (railway) - once the class changes, the applicable deduction clause changes with it.

Applicability Boundaries

• The threshold is judged on individual hole area, not cumulative hole area; "0.30 m2 or less" includes equality (the equal side does not deduct).
• The formwork 0.30 m2 threshold in local quotas expressly targets wall and slab members; raft edge forms with no hole contact faces need no test - where a through hole touches the formwork per the design, judge on the actual contact area.
• Regional and sector systems word things differently (whether "bolt holes" are named; whether equipment-foundation pockets are listed separately); execution follows the pricing basis agreed in the contract (bill measurement standard or local consumption quota / railway budget quota); bill and quota quantities may run on two tracks.
• This decision settles quantity measurement only; whether the quota item's work content already covers hole-forming labour and materials (Jiangsu: "no extra charge") is governed by the quota's work content and cost make-up.
• Local quotas name and split rafts / full rafts differently (flat strip foundations, full rafts, equipment foundations) - locate the member in the executed quota's chapter before applying the deduction rules.

Further Reading

• GB/T 50854-2024 quantity take-off standard for building and decoration works, Annex E "concrete and reinforced concrete works", E.7.1 general notes on cast-in-place members; the measurement rules and item-description requirements of the corresponding formwork items.
• Jiangsu building and decoration consumption standard (2026 edition in the source data), "concrete quantity rules" and "formwork quantity rules" (cast-in-place and precast members, member boundaries, hole deduction clauses).
• Beijing DB11/T 2382-2024 Construction Works Consumption Quota Standard, clause 7.4.12 (network works, "II concrete works"); the same-basis clause in the bridges and culverts chapter.
• Shenzhen SJG 181.2-2024 Municipal Consumption Quota Standard, Volume 2 bridges and culverts, clause 2.2.1.
• Hunan 2024 building and decoration consumption standard (2025 edition in the source data), "formwork quantities of cast-in-place concrete and reinforced concrete", rule 3.
• Railway TB/T 10831-2024 Railway Works Budget Quota Manual, Volume 10 building works, volume notes "measurement rules" (1), (2), (3)2, (9)1.