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MINISTRY OF CONSTRUCTION -------	SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom – Happiness ----------------
No. 06/2021/TT-BXD	Hanoi, June 30, 2021

CIRCULAR

CLASSIFICATION OF CONSTRUCTIONS AND GUIDELINES FOR APPLICATION IN MANAGEMENT OF CONSTRUCTION INVESTMENT

Pursuant to Law on Construction dated June 18, 2014; Law on amendments to Law on Construction dated June 17, 2020;

Pursuant to Law on Architecture dated June 13, 2019;

Pursuant to Decree No. 06/2021/ND-CP dated January 26, 2021 of the Government on elaborating to quality control, construction, and maintenance of constructions;

Pursuant to Decree No. 15/2021/ND-CP dated March 3, 2021 of the Government on elaborating to management of construction project;

Pursuant to Decree No.81/2017/ND-CP dated July 17, 2017 of the Government on functions, tasks, powers, and organizational structure of the Ministry of Construction;

At request of Director General of the State Agency for Construction Quality Inspection;

Minister of Construction promulgates Circular on classification of constructions and guidelines for application in management of construction investment.

Article 1. Scope and regulated entities

1. Scope

This Circular elaborates to classification of constructions and guidelines for application of construction classification in management of construction investment according to Clause 4 Article 5 of Law on Construction 2014 and amendments thereto under Clause 3 Article 1 of Law on amendment to Law on Construction 2020 and Clause 2 Article 3 of Decree No. 06/2021/ND-CP.

2. Regulated entities

This Circular applies to individuals making investment decisions, project developers, owners, managers, users of constructions, domestic, overseas contractors, construction regulatory agencies, and other organizations, individuals relating to construction investment conducted in Vietnamese territory.

Article 2. Principles of determining construction classes

1. Construction classes under this Circular are determined based on following criteria:

a) Level of importance, capacity level: Apply to independent constructions or a group of constructions or a technology line consisting of multiple work items under construction investment projects based on structures under Annex I attached hereto;

b) Scale: Apply to independent constructions under construction investment projects based on types of structures under Annex II attached hereto.

2. Class of an independent construction shall be the highest class determined under Annex I and Annex II attached hereto. In case independent constructions are not specified under Annex I attached hereto, construction classes shall be determined according to Annex II attached hereto and vice versa.

3. Construction class of a combination of constructions or a technology line consisting of multiple work items is determined as follows:

a) In case of groups of constructions or technology lines consisting of multiple work items under Annex I hereof, construction class shall conform to Annex I hereof;

b) In case of groups of constructions of technology lines consisting of multiple work items not specified under Annex I hereof, construction class is determined based on the highest classes of primary constructions (of groups of constructions or technology lines). Classes of primary constructions shall conform to Clause 2 of this Article.

4. Class of current constructions that are repaired, renovated, and upgraded is determined as follows:

a) In case the repair, renovation, or upgrade alters criteria for determining construction classes under Clause 1 of this Article, classes of constructions after repair, renovation, and upgrade are determined according to this Article;

b) For cases other than those under Point a of this Clause, classes of constructions before and after repair, renovation, and upgrade do not change.

Article 3. Application of construction classes in management of construction investment

1. Construction classes under this Circular are applied to serve as the basis for managing following construction investment:

a) Determining entitlement when appraising feasibility reports; appraising or providing remarks for technology for construction investment projects utilizing technologies restricted for transfer or construction investment projects that potentially negatively impact the environment and employ high technology according to Law on Technology Transfer; appraising design for implementation after fundamental design; examining inspection for acceptance during construction and completion of construction;

b) Classifying construction capacity of organizations and individuals to issue certificate of construction capacity and certificate of construction practice;

c) Identifying constructions that do not require construction permit;

d) Identifying constructions that must attend architectural measure examination according to Clause 2 Article 17 of Law on Architecture;

dd) Identifying constructions that require separate technical instructions;

e) Identifying constructions that have major impact on community safety and benefits;

g) Identifying constructions that require professional liability insurance;

h) Identifying constructions that must perform periodic assessment regarding safety of constructions during use;

i) Classifying construction incidents and entitlement for dealing with construction incidents;

k) Managing construction investment cost;

l) Determining duration and amount of construction warranty;

m) Identifying constructions that require maintenance procedures;

m) Other activities according to regulations and law on management of construction investment.

2. Apply construction classes to manage construction investment under Point a Clause 1 of this Article as follows:

a) In case a construction investment project only consists of 1 independent construction: Apply construction class according to Clause 2 Article 2 hereof;

b) In case a construction investment project consists of multiple independent constructions or constructions built in lines: Apply class of the constructions with the highest class determined according to Clause 2 Article 2 hereof;

c) In case a construction investment project consists of groups of primary constructions or technology lines with multiple work items: Apply construction classes determined according to Clause 3 Article 2 hereof;

d) In case a construction investment project consists of multiple primary constructions, multiple primary technology lines or a combination: Apply classes of groups of primary constructions or primary technology lines with the highest classes as determined according to Clause 3 Article 2 hereof.

3. Principles of applying construction classes to manage construction investment specified under Point b through Point n Clause 1 of this Article are as follows:

a) In case the scope is an independent structure, apply construction class determined according to Clause 2 Article 2 hereof.

b) In case the scope is several constructions under construction investment projects, apply construction class determined according to Clause 2 Article 2 hereof to each construction in question;

c) In case the scope is the entire groups of constructions or the entire technology lines with multiple work items, apply construction class determined according to Clause 3 Article 2 hereof. In case a construction investment project includes constructions built in lines, conform to Point d of this Clause;

d) In case the scope is a construction, a number of constructions or the entire constructions under construction investment project for constructions built in lines, apply construction class determined according to Clause 2 Article 2 hereof for each construction built in line.

Article 4. Transition clauses

1. Class of constructions under construction investment projects decided for investment before effective date hereof shall be determined according to regulations and law applicable at the time of approving construction investment projects.

2. In case constructions face design revision after effective date hereof:

a) If revision of construction design does not alter criteria for determining construction class specified under Clause 1 Article 2 hereof, construction class shall be determined according to regulations and law applicable at the time of approving construction investment projects;

b) If revision of construction design alters criteria for determining construction class specified under Clause 1 Article 2 hereof, construction class shall be determined according to this Circular.

Article 5. Entry into force

1. This Circular comes into force from August 15, 2021 and replaces Circular No. 03/2016/TT-BXD dated March 10, 2016 of Minister of Construction and Circular No. 07/2019/TT-BXD of Minister of Construction.

2. Difficulties that arise during the implementation of this Circular should be reported to the Ministry for consideration./.

PP. MINISTER
DEPUTY MINISTER

Le Quang Hung

ANNEX I

CLASSIFICATION OF CONSTRUCTIONS BY LEVEL OF IMPORTANCE OR CAPACITY LEVEL
(Attached to Circular No. 06/2021/TT-BXD dated June 30, 2021 of Minister of Construction)

Schedule 1.1 Classification of constructions serving civil purposes (civil constructions)

No.

Type of construction

Criteria

Construction class

Special

III

1.1.1

Education and training constructions

1.1.1.1 Kindergartens, preschools

Level of importance

Class III

1.1.1.2 Primary school

Total number of students

≥ 700

< 700

1.1.1.3 Lower secondary schools, upper secondary schools, multi-level secondary schools

Total number of students

≥ 1,350

< 1,350

1.1.1.4 Higher education institutions, colleges, professional intermediate schools, vocational education institutions, technical personnel schools, professional operation schools

Total number of students

> 8,000

5,000 ÷ 8,000

< 5,000

1.1.2

Medical constructions

1.1.2.1 General hospitals, specialized hospitals from central to local administrative divisions (Central hospitals are no lower than class I)

Total number of hospital beds

> 1,000

500 ÷ 1,000

250 ÷< 500

< 250

1.1.2.2 Biosafety testing centers (Biosafety level is determined according to regulations of medical sector)

Biosafety level

Biosafety level 4

Biosafety level 3

Biosafety level 1 and level 2

1.1.3

Sports constructions

1.1.3.1 Stadiums, outdoor sports competition grounds with bleachers (National stadiums, national sports competition grounds are no lower than class I)

Seat capacity (thousand seats)

> 40

> 20 ÷ 40

5 ÷ 20

< 5

1.1.3.2 Training facilities for sports with bleachers (National sports stadiums are no lower than class I)

Seat capacity (thousand seats)

> 7.5

5 ÷ 7.5

2 ÷ < 5

< 2

1.1.3.3 Golf course

Number of holes

≥ 36

18 ÷ < 36

< 18

1.1.3.4 Outdoor swimming pools and sports grounds

Level of importance

Eligible for national sports competition

Sports activities

1.1.4

Cultural constructions

1.1.4.1 Convention centers, cultural houses, clubs, dance clubs, and other crowded cultural constructions (National convention centers are no lower than class I)

Total capacity (thousand people)

> 3

> 1.2 ÷ 3

> 0.3 ÷ 1.2

≤ 0.3

1.1.4.2 Theaters, cinemas, circuses

Total capacity (thousand people)

> 3

> 1.2 ÷ 3

> 0.3 ÷ 1.2

≤ 0.3

1.1.4.3 Museums, libraries, exhibits, exhibition

Level of importance

Country

Province, sector/field

Remaining cases

1.1.5

Markets

Number of businesses

> 400

≤ 400

1.1.6

Religious constructions

Level of importance

Class III

1.1.7

Head offices of regulatory authorities, political organization, socio-political organizations

Level of importance

National Assembly building, President building, Government head office, Central Communist Party head office; other particularly important constructions

Head office of Communist Party authority of provinces; People’s Committees and People’s Councils of provinces; ministries, general departments and equivalent; People's Court, Supreme People’s Procuracy

Head office of Communist Party authority of districts; People’s Councils, People’s Committees of districts; departments, agencies and equivalent; People's Courts, People’s Procuracy of provinces

Head office of Communist Party authority, People’s Councils, People’s Committees of communes; sub-departments and equivalent; People's Courts, People’s Procuracy of districts

Note:

- In case other civil constructions with use purposes suit constructions under Schedule 1.1, employ schedule 1.1 to determine classes depending on level of importance or capacity level.

- Consult examples on classes of civil constructions under Annex III.

Schedule 1.2 Classification of constructions for industrial production (industrial constructions)

No.

Type of construction

Criteria

Construction class

Special

III

1.2.1

Constructions producing construction materials and products

1.2.1.1 Mining for construction materials (limestone cement, clay cement, cement additives, kaolin, feldspar, fire clay, white clay, white sand, dolomite, limestone for line, construction stones, minerals serving as construction materials)

a) Constructions using explosive materials

Level of importance

Class II

b) Constructions not using explosive materials

Total capacity (million m3 product/year)

≥ 1

< 1

1.2.1.2 Clinker and cement manufacturing factories

Total capacity (million tonne/year)

≥ 1

< 1

1.2.1.3 Grinding stations, cement distribution stations

Total capacity (million tonne/year)

≥ 0.3

< 0.3

1.2.1.4 Manufacturing factories for regular concrete products, components; cement brick manufacturing factories

Total capacity (thousand m3 final product/year)

> 150

≤ 150

1.2.1.5 Manufacturing factories for centrifugal concrete components, prestressed concrete components, pre-molded concrete walls

Total capacity (thousand m3 final product/year)

> 150

30 ÷ 150

< 30

1.2.1.6 Manufacturing factories for light concrete bricks, walls using light concrete

Total capacity (thousand m3 final product/year)

> 200

100 ÷ 200

< 100

1.2.1.7 Manufacturing bricks from clay

Total capacity (million standard compliant brick/year)

> 40

20 ÷ 40

< 20

1.2.1.8 Tiling product factories

a) Ceramic tile factories

Total capacity (thousand m2 final product/year)

> 5

3 ÷ 5

< 3

b) Synthetic tile factories

Total capacity (thousand m2 final product/year)

> 1

0.5 ÷ 1

< 0.5

c) Natural tile factories

Total capacity (thousand m2 final product/year)

> 0.3

0.1 ÷ 0.3

< 0.1

1.2.1.9 Ceramic sanitary ware factories

Total capacity (million products/year)

0.3 ÷ 1

<0.3

1.2.1.10 Architectural glass factories

Total capacity (million m2 of products/year)

≥ 20

< 20

1.2.1.11. Glass product factories (tempered glass, insulating glass, laminated glass, etc.)

Total capacity (million m2 of products/year)

≥ 0.2

< 0.2

1.2.1.12 Industrial lime and post-lime product factories

Total capacity (million tonne of products/year)

> 0.3

0.1 ÷ 0.3

< 0.1

1.2.1.13 Fire-resistant material factories

Total capacity (million tonne of products/year

>10

5 ÷ 10

1.2.1.14 Fibre cement sheet factories

Total capacity (million m2 of products/year)

≥0.3

<0.3

1.2.1.15 Dry mortar factories

Total capacity (million tonne of products/year)

≥0.3

<0.3

1.2.1.16 Plaster sheet factories

Total capacity (million m2 of products/year)

>20

10 ÷ 20

<10

1.2.2

Metallurgy and manufacturing engineering constructions

1.2.2.1 Metallurgy factories

a) Colored metallurgy factories

Total productivity (million tonne of final products/year)

> 0.5

0.1 ÷ 0.5

< 0.1

b) Steel work, rolling factories

Total productivity (million tonne of final products/year)

> 1

0.5 ÷ 1

< 0.5

1.2.2.2 Steel and cast iron compounds

Blast furnace volume (thousand m3)

> 1

≤ 1

1.2.2.3 Motor and agricultural machine manufacturing factories

Total productivity (thousand of products/year)

> 5

2.5 ÷ 5

< 2.5

1.2.2.4 Machinery tool and industrial equipment manufacturing factories

Total productivity (thousand of products/year)

> 1

0.5 ÷ 1

< 0.5

1.2.2.5 Lifting equipment manufacturing factories

Total productivity (thousand tonne of products/years)

> 200

≤ 200

1.2.2.6 Construction machinery manufacturing factories

a) Bulldozer, excavator manufacturing and assembling factories

Total productivity (products/year)

> 250

≤ 250

b) Static, vibrating road roller manufacturing and assembling factories

Total productivity (products/year)

> 130

≤ 130

c) Self-propelled crane manufacturing and assembling factories

Total productivity (products/year)

> 40

≤ 40

1.2.2.7 Complete equipment manufacturing factories

Total productivity (thousand tonne of equipment/year)

> 10

5 ÷ 10

< 5

1.2.2.8 Traffic equipment manufacturing, assembling factories

a) Automobile manufacturing and assembling factories

Total productivity (thousand of vehicles/year)

> 10

5 ÷ 10

< 5

b) Motorbike manufacturing and assembling factories

Total productivity (thousand of vehicles/year)

> 500

≤ 500

c) Railway locomotive manufacturing and assembling factories

Total productivity (thousand of locomotives/year)

> 1

0.5 ÷ 1

< 0.5

d) Inland watercraft assembling facilities

Weight of vessel (thousand DWT)

> 30

10 ÷ 30

5 ÷ <10

< 5

đ) Maritime vessel assembling facilities

Weight of vessel (thousand DWT)

> 70

> 40 ÷ 70

> 20 ÷ 40

> 5 ÷ 20

≤ 5

1.2.3

Mining and mineral processing constructions

1.2.3.1 Underground coal mine

Total productivity (million tonne of coal/year)

> 1

0.3 ÷ 1

< 0.3

1.2.3.2 Underground mineral mine

Total productivity (million tonne of mineral/year)

> 3

1 ÷ 3

< 1

1.2.3.3 Open coal mine

Total productivity (million tonne of coal/year)

≥ 2

< 2

1.2.3.4 Open mineral mine

Total productivity (million tonne of mineral/year)

≥ 2

< 2

1.2.3.5 Coal preparation factories

Total productivity (million tonne/year)

> 5

2 ÷ 5

< 2

1.2.3.6 Ore preparation/enrichment factories (including preparation of bauxite ore)

Total productivity (million tonne/year)

> 7

3 ÷ 7

< 3

1.2.3.7 Alumina manufacturing constructions

Level of importance

Class I

1.2.4

Petroleum constructions

1.2.4.1 Petroleum rig at sea

Level of importance

Class I

1.2.4.2 Oil filtering constructions

Total capacity (million tonne/year)

≥ 10

< 10

1.2.4.3 Gas processing constructions

Total capacity (million m3 of gas /day)

≥ 10

< 10

1.2.4.4 Biofuel manufacturing constructions

Total capacity (thousand tonne of products/year)

> 500

200 ÷ 500

< 200

1.2.4.5 Gasoline storage

Total storage volume (thousand m3)

>100

5 ÷ 100

0,21 ÷ < 5

< 0,21

1.2.4.6 Liquefied gas storage, liquefied gas extracting and loading stations

Total storage volume (thousand m3)

> 100

5 ÷ 100

< 5

1.2.5

Energy constructions

1.2.5.1 Thermoelectricity constructions

Total capacity (MW)

> 2,000

600 ÷ 2,000

50 ÷ < 600

< 50

1.2.5.2 Nuclear electricity constructions

Level of importance

Special class

1.2.5.3 Hydroelectricity constructions

a) Power plants

Total installed capacity (MW)

> 1,000

> 50 ÷ 1,000

> 30 ÷ 50

≤ 30

b) Reservoirs

Reservoir volume with regular water level (million m3)

> 1,000

> 200 ÷ 1,000

> 20 ÷ 200

≥ 3 ÷ 20

< 3

c) Dams

(Scale and characteristics of dams)

Earth-filled dams with the greatest height (m)

> 100

> 70 ÷ 100

> 25 ÷ 70

>10 ÷ 25

≤ 10

> 35 ÷ 75

> 15 ÷ 35

> 8 ÷ 15

≤ 8

> 15 ÷ 25

> 5 ÷ 15

≤ 5

Concrete, reinforced concrete dams with the greatest height (m)

> 100

> 60 ÷ 100

> 25 ÷ 60

> 10 ÷ 25

≤ 10

> 25 ÷ 50

> 10 ÷ 25

> 5 ÷ 10

≤ 5

> 10 ÷ 20

> 5 ÷ 10

≤ 5

Note:

1. Class of hydroelectricity constructions shall be the highest class determined according to criteria for classifying power plants, reservoirs, and dams (in which A, B, C refer to typical geography foundation: A refers to rock foundation; B refers to sand, dry earth clump, tough clay foundation; C refers to fully-saturated clay foundation).

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

2. Classes of constructions on “Energy routes” such as intakes, transmission lines (channels, sewers, tunnels), water towers, pressure pipes, discharge channels or tunnels, etc. are determined according to classes of hydroelectricity power plants under Point a section 1.2.5.3.

3. Classes of constructions on “Front routes” such as dams, surface discharge channel, sluice ways, spillways, other water collection constructions, etc. are determined according to classes of dams under Point c section 1.2.5.3.

4. Classes of relevant constructions such as administration buildings, fences, roads, etc. in hydroelectricity construction projects are determined depending on types of constructions as guided under this Circular.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

Note:

With respect to pumped-storage hydroelectricity constructions: Lower construction class determined according to this section by 1 but no lower than class III in all cases.

1.2.5.4 Wind power constructions

Total capacity (MW)

≥ 50

> 15 ÷ < 50

> 3 ÷ 15

≤ 3

1.2.5.5 Solar power constructions

Total capacity (MW)

≥ 50

> 15 ÷ < 50

> 3 ÷ 15

≤ 3

1.2.5.6 Geothermal electricity constructions

Total capacity (MW)

> 10

5 ÷ 10

< 5

1.2.5.7 Tidal power constructions

Total capacity (MW)

> 50

30 ÷ 50

< 30

1.2.5.8 Waste-to-energy constructions

Total capacity (MW)

> 70

> 15 ÷ 70

5 ÷ 15

< 5

1.2.5.9 Biomass constructions

Total capacity (MW)

> 30

10 ÷ 30

< 10

1.2.5.10 Biogas constructions

Total capacity (MW)

> 15

5 ÷ 15

< 5

1.2.5.11 Powerlines and transformers

Voltage (kV)

≥ 500

220

110

> 35 ÷< 110

≤ 35

1.2.5.12 Stores/retail shops of gasoline, oil, liquefied gas; electricity, battery supply/recharging stations.

Level of importance

Class III

1.2.6

Chemical constructions

1.2.6.1 Manufacturing constructions for fertilizers and pesticides

a) Manufacturing constructions for simple, complex fertilizers (containing chemical reactions, including: Urea, DAP, MAP, SA, compound NPK, superphosphate, etc.)

Total productivity (thousand tonne of products/year)

≥ 50

10 ÷< 50

< 10

b) Manufacturing constructions for other fertilizers (mixed, thermal, microbial solutions, etc. – not creating chemical reactions)

Total capacity (thousand tonne of products/year)

≥ 300

100 ÷< 300

< 100

c) Manufacturing, supply, transferring, packaging constructions for pesticides

Total capacity (thousand tonne of products/year)

> 15

10 ÷ 15

< 10

1.2.6.2 Manufacturing constructions for basic chemicals, petroleum, pharmaceutical chemical, chemical cosmetics

a) Manufacturing constructions for basic chemicals (acid, base, clorine, etc.), toxic chemicals, inorganic chemical, organic chemicals, other industrial chemicals (including pure chemicals, salt, etc.)

Total capacity (thousand tonne of products/year)

≥ 10

< 10

b) Manufacturing constructions, extracting stations for petroleum products (ingredients of plastic, PP, PE, PVC, PS, ABS, PET, SV, fiber, DOP, SM, VCM, Polystyren, PTA, MEG, BTX, synthetic rubber and other products)

Total capacity (thousand tonne of products/year)

≥ 50

< 50

c) Manufacturing constructions for pharmaceutical chemical products (extracting, preparing natural chemical compounds and synthesizing chemicals)

Note: Does not include manufacturing of chemicals and medical equipment: preparation, processing, manufacturing of eastern medicine

Level of importance

Class I

d) Manufacturing constructions for cleaning products, cosmetics (washing cream, washing powder, cleaning liquid, washing soap; shampoo, body washing soap, toothpaste, soap, etc.)

Total productivity (thousand tonne of products /năm)

≥ 15

10 ÷< 15

< 10

1.2.6.3 Manufacturing constructions for products for chemical electricity Công trình sản xuất sản phẩm nguồn điện hóa học

a) Manufacturing constructions for chemical batteries

Total productivity (million cells/year)

> 250

150 ÷ 250

< 150

b) Manufacturing, recycling constructions for rechargeable batteries

Total productivity (thousand kWh/year)

> 300

100 ÷ 300

< 100

c) Manufacturing constructions for welding rods

Total productivity (thousand tonne of products/year)

≥ 3

< 3

1.2.6.4 Manufacturing constructions, extracting stations for industrial gases (O2, N2, Ar, CO, CO2, He, H2, Xe, CH4, C2H2 and other industrial gases)

a) Manufacturing constructions for industrial gases

Total productivity (thousand m3 of gas/h)

> 15

8.5 ÷ 15

< 8.5

b) Extracting stations for industrial gases

Maximum storage (tonne)

≥ 100

< 100

1.2.6.5 Manufacturing constructions for rubber products

a) Manufacturing constructions for tires and wheels of automobiles and tractors

Total productivity (million pieces/year)

> 1

0.5 ÷ 1

< 0.5

b) Manufacturing constructions for automobile and bicycle tires and wheels

Total productivity (million pieces/year)

> 5

1 ÷ 5

< 1

c) Manufacturing constructions for conveyor belts

Total productivity (thousand m2 of products/year)

> 500

200 ÷ 500

< 200

d) Manufacturing constructions for technical rubber

Total productivity (million products/year)

> 1.5

0.5 ÷ 1.5

< 0.5

1.2.6.6 Manufacturing constructions for paint and printing ink

a) Manufacturing constructions for paint

Total productivity (thousand tonne of products/year)

> 100

> 20 ÷ 100

10 ÷ 20

< 10

b) Manufacturing constructions for printing ink

Total productivity (thousand tonne of products/year)

> 20

5 ÷ 20

< 5

1.2.6.7 Preparation structures for apatite ore

Total productivity (thousand tonne of products/year)

≥ 100

< 100

1.2.6.8 Manufacturing and storing constructions for explosives and precursors of explosives

a) Manufacturing constructions for industrial explosives and precursors of explosives

Level of importance

Special class

b) Storage for industrial explosives

Pit storage, underground storage

Level of importance

Class I

Fixed above-ground and semi-underground storage

Storage capacity (tonne)

> 10

≤ 10

Mobile storage

Level of importance

Class II

c) Storage for precursors of explosives

Pit storage, underground storage

Level of importance

Class I

Fixed above-ground and semi-underground storage

Storage capacity (tonne)

> 50

≤ 50

Mobile storage

Level of importance

Class II

1.2.7

Light industry constructions

1.2.7.1 Food industry

a) Dairy factories

Total productivity (million liter/year)

> 100

30 ÷ 100

< 30

b) Confectionary, instant noodle manufacturing factories

Total productivity (thousand tonne of products/year)

> 25

5÷25

< 5

c) Cooking oil, additive manufacturing factories

Total productivity (thousand tonne of products/year)

> 150

50 ÷150

< 50

d) Beverage manufacturing factories

Total productivity (million liter/year)

> 100

25 ÷ 100

< 25

1.2.7.2 Consumer industry

a) Fibre factories

Total productivity (thousand tonne of products/year)

> 75

30 ÷ 75

< 30

b) Textile factories

Total productivity (million m2 of products/year)

> 25

5 ÷ 25

< 5

c) Printing, dyeing factories (for textile)

Total productivity (million m2 of products/year)

> 35

10 ÷ 35

< 10

d) Textile product manufacturing factories

Total productivity (million products/year)

> 10

2 ÷ 10

< 2

đ) Leather and leather product manufacturing factories

Total productivity (million products/year)

> 12

1 ÷ 12

< 1

e) Plastic product manufacturing factories

Total productivity (thousand tonne of products/year)

> 15

2 ÷ 15

< 2

g) Ceramic ware and glassware manufacturing factories

Total productivity (thousand tonne of products/year)

> 25

3 ÷ 25

< 3

h) Pulp and paper factories

Total productivity (thousand tonne of products/year)

> 100

60 ÷ 100

< 60

i) Cigarette manufacturing factories

Total productivity (million packs of cigarettes/year)

> 200

50 ÷ 200

< 50

k) Electronic appliance (television, computer, and equivalent), electrical refrigeration equipment (air-conditioners, fridges, and equivalent) manufacturing/assembling facilities

Total productivity (thousand products/year)

> 300

100 ÷ 300

< 100

l) Communication and electronic appliance, component, part (electrical circuit, IC, and equivalent) manufacturing factories

Total productivity (million products/year)

> 400

300 ÷ 400

< 300

m) Currency printing factories

Level of importance

Special class

1.2.7.3 Agricultural, fishery product processing industry

a) Fishery product processing factories

Total productivity (tonne of ingredient/day)

> 300

100 ÷ 300

< 100

b) Canned food processing factories

Total productivity (tonne of ingredient/day)

≥ 100

< 100

c) Rice milling, polishing factories

Total productivity (thousand tonne of products/year)

> 200

100 ÷ 200

1 ÷ < 100

< 1

Ghi chú:

- In case other industrial constructions with use purposes suitable with constructions under Schedule 1.2, use Schedule 1.2 to determine to determine construction class based on level of importance or capacity.

- Consult examples of identifying classes of industrial constructions under Annex III.

Schedule 1.3 Classification of constructions providing technical infrastructure facilities and utilities (technical infrastructure constructions)

No.

Type of construction

Criteria

Construction class

Special

III

1.3.1

Water supply constructions

1.3.1.1 Water plants, clean water processing constructions (including mud processing constructions)

Total capacity (thousand m3/24 hours)

≥ 30

10 ÷ < 30

< 10

1.3.1.2 Raw water, clean water or step-up transformers stations (including water reservoirs if any)

Total capacity (thousand m3/24 hours)

≥ 40

12 ÷ < 40

< 12

1.3.2

Water drainage constructions

1.3.2.1 Regulating reservoirs

Area (ha)

≥ 20

15 ÷ < 20

1 ÷ < 15

< 1

1.3.2.2 Rainwater pumping stations (including reservoirs if any)

Total capacity (m3/s)

≥ 25

10 ÷ < 25

< 10

1.3.2.3 Wastewater processing constructions

Total capacity (thousand m3/24 hours)

≥ 20

10 ÷ < 20

< 10

1.3.2.4 Wastewater pumping stations (including reservoirs if any)

Total capacity (m3/h)

≥ 1,200

700 ÷ < 1,200

< 700

1.3.2.5 Mud processing constructions

Total capacity (m3/24 hours)

≥ 1,000

200 ÷ < 1,000

< 200

1.3.3

Solid waste processing constructions

1.3.3.1 Regular solid waste processing constructions

a) Transit stations

Total capacity (tonne/24 hours)

≥ 500

200 ÷ < 500

100 ÷ < 200

< 100

b) Solid waste processing facilities

Total capacity (tonne/24 hours)

≥ 500

200 ÷ < 500

50 ÷ < 200

< 50

1.3.3.2 Hazardous solid waste disposal facilities

Total capacity (tonne/24 hours)

> 100

20 ÷ 100

< 20

1.3.4

Parks

Area (ha)

> 20

10 ÷ 20

5 ÷ < 10

< 5

1.3.5

Cemeteries

National Cemetery: Class I.

Area (ha)

> 60

30 ÷ 60

10 ÷ < 30

< 10

1.3.6

Funeral homes

Level of importance

National Funeral parlor: Class I; Other cases: Cấp II.

1.3.7

Crematorium

Level of importance

Class II.

1.3.8

Automobile garage; vehicle, machinery, equipment spaces and storage

1.3.8.1 Underground automobile garages*

Number of automobile parking spots

≥ 500

300 ÷ < 500

< 300

1.3.8.2 Above-ground automobile garages*

≥ 1,000

500 ÷ < 1,000

100 ÷ < 500

< 100

1.3.8.3 Vehicle, machinery, equipment spaces and storage (without roof)

Total area (ha)

> 2.5

≤ 2.5

1.3.9

Telecommunication transmission lines

Level of importance

Multi-national

Multi-provincial

Provincial

Note:

- In case other technical infrastructure constructions having use purposes suitable with constructions under Schedule 1.3, employ Schedule 1.3 to determine construction classes depending on level of importance or capacity level.

- (*): For automobile garages, parking spaces are applicable to passenger automobiles with up to 9 seats or trucks under 3,500 kg. In case an automobile garage provide parking spaces for both automobiles and motorbikes, every 6 parking spaces for motorbikes shall be equivalent to 1 parking space for automobile.

- Examples regarding classification of technical infrastructure constructions are under Annex III.

Schedule 1.4 Classification of traffic constructions

No.

Type of construction

Criteria

Construction class

Special

III

1.4.1

Road constructions

1.4.1.1 Automobile expressways

Design velocity (km/h)

> 100

100

80; 60

1.4.1.2 Automobile roads

Traffic rate (converted thousand vehicles/24 hours)

design velocity (km/h)

> 30

> 100

10 ÷ 30

100

3 ÷ < 10

0.5 ÷ < 3

< 0.5

< 40

1.4.1.3 Urban roads:

- Identify construction classes based on all criteria and apply the highest class.

- For urban roads with total length ≤ 1,000 m: Lower construction classes determined according to this Schedule by 1 class but no lower than Class IV

- Elevated roads in urban areas shall conform to criteria under this Schedule and structure under 2.5.1 of Schedule 2 Annex II

a) Number of lanes

≥ 8

2; 4

b) Design velocity (km/h)

≥ 80

20 ÷ 30

1.4.1.4 Leveled, priority junctions

Converted vehicle rate (thousand vehicles/24 hours)

≥ 30

10 ÷ < 30

3 ÷ < 10

< 3

1.4.1.5 Other roads:

a) Roads in rural areas

b) Specialized roads for transportation, travel of individuals or organizations but not including Section 1.4.1.1 through 1.4.1.3 (e.g. forestry routes, mining routes, construction routes, roads in resorts, vacation areas, etc.)

Note: Class of automobile test roads shall conform to 1.4.1.2

c) Bicycle roads; pedestrian roads

Level of importance

All scale

1.4.2

Railway constructions

1.4.2.1 Urban railways (including underground railways, above-ground railways, elevated electric railways, automatic monorail)

Level of importance

Special class

1.4.2.2 National railways, 1.435 mm of track gauge

Note: High-speed railways refer to a form of national railways with design velocity of at least 200 km/h trở lên, with 1,435 mm of track gauge, double track, electrified railways

Design velocity (km/h)

≥ 200

120 ÷ < 200

80 ÷ < 120

< 80

1.4.2.3 National railways, 1,000 mm of track gauge; overlapping tracks, track gauge of (1,435 – 1,000) mm

Design velocity (km/h)

100 ÷ 120

60 ÷ < 100

< 60

1.4.2.4 Specialized, regional railways

Design velocity (km/h)

≥ 70

< 70

1.4.3

Bridges

1.4.3.1 Floating bridges

Converted traffic rate (vehicle/24 hours)

> 3,000

1,000 ÷ 3,000

700 ÷ < 1,000

500 ÷ < 700

1.4.4

Inland waterway constructions

1.4.4.1 Inland watercraft repair stations

Weight load of vessels (thousand DWT)

> 30

10 ÷ 30

5 ÷ < 10

< 5

1.4.4.2 Inland waterway ports and harbors

a) Cargo ports and docks

Weight load of vessels (thousand DWT)

> 5

3 ÷ 5

1.5 ÷ < 3

0.75 ÷ < 1.5

< 0.75

b) Passenger ports and docks

Largest vehicle size (seats)

> 500

300 ÷ 500

100 ÷ < 300

50 ÷ < 100

< 50

1.4.4.3 Ferry stations

Traffic rate (converted vehicle/24 hours)

> 1,500

700 ÷ 1,500

400 ÷ < 700

200 ÷ < 400

< 200

1.4.4.4 Locks

Weight load of vessels (thousand DWT)

> 3

1.5 ÷ 3

0.75 ÷ < 1.5

0.2 ÷ < 0.75

< 0.2

1.4.4.5 Waterway with width (B) and depth (H) of water for vessel operation:

a) On lakes, rivers, bays, waterways leading to islands

Width B (m) and depth H (m) of water for vessel operation

B > 120

H > 5

B =90 ÷ < 120

H = 4 ÷ 5

B = 70 ÷ < 90

H = 3 ÷ < 4

B = 50 ÷ < 70

H = 2 ÷ < 3

B < 50

H < 2

b) On canals

Width B (m) and depth H (m) of water for vessel operation

B > 70

H > 5

B = 50 ÷ < 70

H = 4 ÷ 5

B = 40 ÷ < 50

H = 3 ÷ < 4

B = 30 ÷ < 40

H = 2 ÷ < 3

B < 30

H < 2

1.4.5

Maritime constructions

1.4.5.1 Sea ports; transshipment areas; anchoring areas; storm avoidance areas

a) Cargo and public affair ports

Weight load of vessels (thousand DWT)

> 70

> 40 ÷ 70

> 20 ÷ 40

> 5 ÷ 20

≤ 5

b) Passenger ports

Total vessel volume (thousand GT)

> 150

> 100 ÷ 150

> 50 ÷ 100

> 30 ÷ 50

≤ 30

c) Transshipment areas; anchoring areas; storm avoidance areas

Weight load of vessels (thousand DWT)

> 70

> 40 ÷ 70

> 20 ÷ 40

> 5 ÷ 20

≤ 5

1.4.5.2 Vessel, watercraft repair facilities; vessel locks, docks and other lifting, lowering structures

Weight load of vessels (thousand DWT)

> 70

> 40 ÷ 70

> 20 ÷ 40

> 5 ÷ 20

≤ 5

1.4.5.3 Sea lanes

Width of a lane B (m)

Depth of water for vessel operation Hct (m)

B > 190

Hct ≥ 16

140 < B ≤ 190

14 ≤ Hct < 16

80 < B ≤ 140

8 ≤ Hct < 14

50 < B ≤ 80

5 ≤ Hct < 8

B ≤ 50

Hct < 5

1.4.5.4 Other maritime constructions:

a) Maritime buoys

Buoy diameter D (m)

D ≥ 10

5 ≤ D < 10

3 ≤ D < 5

2 ≤ D < 3

D < 2

b) Regulation works, embankments, sand barriers, current redirection embankments

Greatest height of constructions or depth of water H (m)

H > 16

12 < H ≤ 16

8< H ≤ 12

5≤ H ≤ 8

< 5

1.4.6

Aviation constructions

1.4.6.1 Aviation terminals (Primary terminals)

Passengers (million passengers/year)

≥ 10

< 10

1.4.6.2 Flight zones

Airport level according to regulations of International Civil Aviation Organizations (ICAO)

4E airports or higher

Airports lower than 4E

1.4.6.3 Constructions for guaranteeing flight activities (Air traffic control towers, area control areas, approach control centers, primary/secondary radar stations; not including 1.4.6.2 and 1.4.6.4)

Level of importance

International airports

Domestic airports, aerodromes

1.4.6.4 Aircraft hangar

Level of importance

Class I

Note:

- For other traffic constructions having use purposes suitable with constructions under Schedule 1.4, employ Schedule 1.4 to determine construction classes depending on level of importance or capacity level.

- Consult examples on classes of traffic constructions under Annex III.

Schedule 1.5 Classification of constructions serving agriculture and rural development (agriculture and rural development)

No.

Type of construction

Criteria

Construction class

Special

III

1.5.1

Irrigation constructions

1.5.1.1 Watering constructions (calculated for watered area) ỏ drainage constructions (calculated for natural drainage area)

Area (thousand ha)

> 50

> 10 ÷ 50

> 2 ÷ 10

≤ 2

1.5.1.2 Reservoirs with regular water level

Volume (million m3)

> 1,000

> 200 ÷ 1,000

> 20 ÷ 200

≥ 3 ÷ 20

< 3

1.5.1.3 Constructions for supplying unprocessed water sources for other sectors that use water

Flow rate (m3/s)

> 20

> 10 ÷ 20

> 2 ÷ 10

≤ 2

1.5.2

Irrigation constructions: Determine classes according to Decisions on classification of Ministry of Agriculture and Rural Development as authorized by the Government under Clause 2 Article 2 of Decree No. 113/2007/ND-CP dated June 28, 2007 of the Government.

Note:

- For other agriculture and rural development constructions having use purposes suitable with constructions under constructions under Schedule 1.5, employ Schedule 1.5 to determine classes according to level of importance or capacity level.

- For new animal husbandry facilities, cultivating facilities, forestry facilities, salt farming facilities, fishery facilities, rural development constructions and other agriculture and rural development constructions, due to specific characteristics, constructions investment for these constructions usually include following items: Civil constructions, industrial constructions, traffic constructions, irrigation constructions, technical constructions, etc. thus classification of constructions shall be considered on a case-by-case basis according to regulations hereof.

- Consult examples regarding classification of agriculture and rural development constructions under Annex III.

ANNEX II

CONSTRUCTION CLASSIFICATION BY STRUCTURES
(Attached to Circular No. 06/2021/TT-BXD dated June 30, 2021 of Minister of Construction)

Schedule 2. Classification of constructions by structures

No.

Construction type

Criteria

Construction class

Special

III

2.1

2.1.1 Houses, house-like structures

Structures of detached houses, detached houses combining with other civil purposes are determined by structures under this section. Mansions are no lower than class III.

2.1.2 Multi-storey structures with floors (not including structures under 2.2)

2.1.3 Large single frame structures (not including structures under 2.3 and2.5)

Example: Gates, outhouses, conveyor bridges, traffic sign frames, structures at toll booths and other similar large single structures.

a) Height (m)

> 200

> 75 ÷ 200

> 28 ÷ 75

> 6 ÷ 28

≤ 6

b) Number of above grade storey

> 50

25 ÷ 50

8 ÷ 24

2 ÷ 7

c) Total floor area (thousand m2)

> 30

> 10 ÷ 30

1 ÷ 10

< 1

d) Largest structural span (m)

> 200

100 ÷ 200

50 ÷ < 100

15 ÷ < 50

< 15

đ) Underground depth (m)

> 18

6 ÷ 18

< 6

e) Underground storey

≥ 5

2 ÷ 4

2.2

2.2.1 Pillar, tower, pole structures in civil, industrial, traffic constructions (not including 2.2.3)

Examples: Monuments, advertising poles/towers, power transmission pillars, chimneys, traffic signal poles and similar structures.

Height of structures (m)

> 200

> 75 ÷ 200

> 28 ÷ 75

> 6 ÷ 28

≤ 6

2.2.2 Pillar, tower, pole structures in infrastructure constructions

Examples: Antennas, radio/television towers; BTS poles; lamp posts, electrical posts in lighting systems, etc.

Height of structures (m)

≥ 300

150 ÷ < 300

75 ÷ < 150

> 45 ÷ < 75

≤ 45

2.2.3 Lighthouses

Height of structures (m)

≥ 58

26,5 ÷ < 58

7,5 ÷ < 26,5

< 7,5

2.3

Suspension cable

a) Height of support beams (m) or height from ground level, water level (m)

> 200

> 75 ÷ 200

> 28 ÷ 75

> 6 ÷ 28

≤ 6

b) Greatest distance between 2 support beams (m)

≥ 1,000

500 ÷ <1,000

200 ÷ < 500

50 ÷ < 200

< 50

2.4

Tank, silo structures: (swimming pools, tanks/wells for liquid, gas, dismantled materials; technical tanks for machinery/equipment; silos; water towers and similar structures).

For container structures of hazardous substances (dangerous to health of human, animals, plants): raise classes determined according to this Schedule by 1 class but not lower than class II and not special class.

a) Volume (thousand m3)

> 15

5 ÷ 15

1 ÷ < 5

< 1

b) Height of container structures (m)

≥ 75

> 28 ÷ < 75

6 ÷ 28

< 6

c) Underground depth (m)

> 18

> 6 ÷ 18

> 3 ÷ 6

≤ 3

2.5

Traffic bridges

2.5.1 Road bridges: Classify according to a) and b)

2.5.2 Railway bridges: Classify according to b) and c)

a) Largest structural span (m)

> 150

> 100 ÷ 150

> 42 ÷ 100

> 25 ÷ 42

≤ 25

b) Height of piers (m)

> 50

30 ÷ 50

15 ÷ < 30

6 ÷ < 15

< 6

c) Largest structural span (m)

> 100

50 ÷ 100

25 ÷ < 50

< 25

2.5.3 Bridges for pedestrians, cyclists; Local suspension bridges (for pedestrians, livestock, bicycles, motorbikes/mopes and other motor vehicles; single structure suspension bridges on rural roads and width no larger than 3.5 m)

a) Height of structures (m)

> 50

25 ÷ 50

< 25

b) Height of piers or height from the lowest point of girders to ground level or water level below (m)

> 30

15 ÷ 30

< 15

2.6

2.6.1 Tunnels (traffic tunnels, road, railway tunnels; irrigation tunnels, hydroelectricity tunnels, etc.)

This section does not include following tunnels: Subway tunnels, technical tunnels for factories (section 2.10.4.b) and tunnels for mining resources and minerals.

a) Total length (m)

> 1.500

500 ÷ 1,500

100 ÷ < 500

< 100

b) Cross-section area based on clearance dimension of tunnels (m2)

≥ 100

30 ÷ < 100

< 30

c) Tunnel outer structures

Having outer structures

Having no outer structures

2.6.2 Semi-tunnels serving road traffic, railway traffic and to prevent falling objects

Total length (m)

> 1,500

500 ÷ 1,500

100 ÷< 500

< 100

2.7

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Walls and embankments

For walls and embankments with total length ≤ 500 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

2.7.1 Walls (Earthen walls on land, not including 2.9)

Classification of walls used in water body regulating affairs under 2.11 and 2.12 shall also include criteria of this section

a) Rock foundation

Wall height (m)

> 25 ÷ 40

> 15 ÷ 25

> 8 ÷ 15

≤ 8

b) Clay, earth clump, tough clay foundation

> 12 ÷ 20

> 5 ÷ 12

≤ 5

c) Fully-saturated clay foundation

> 10 ÷ 15

> 4 ÷ 10

≤ 4

2.7.2 Embankments protecting river banks, lakes used in construction investment projects but not including 2.9 and 2.11.2

Embankment height (m) or water or water depth (m)

> 8

> 5 ÷ 8

> 3 ÷ 5

≤ 3

2.8

Dams and other pressured irrigation, hydroelectricity constructions

2.8.1 Earthen dams of all kinds

a) Rock foundation

Dam height (m)

> 100

> 70 ÷ 100

> 25 ÷ 70

> 10 ÷ 25

≤ 10

b) Clay, earth clump, tough clay foundation

> 35 ÷ 75

> 15 ÷ 35

> 8 ÷ 15

≤ 8

c) Fully-saturated clay foundation

> 15 ÷ 25

> 5 ÷ 15

≤ 5

2.8.2 Concrete, reinforced concrete dams and other pressured irrigation, hydroelectricity constructions

a) Rock foundation

Dam height (m)

> 100

> 60 ÷ 100

> 25 ÷ 60

> 10 ÷ 25

≤ 10

b) Clay, earth clump, tough clay foundation

> 25 ÷ 50

> 10 ÷ 25

> 5 ÷ 10

≤ 5

c) Fully-saturated clay foundation

> 10 ÷ 20

> 5 ÷ 10

≤ 5

2.9

Reinforced structures (by tiling, concrete, or other solutions other than earthened according to 2.7) with pitched surfaces

Height from the bottom to the top of pitched surfaces (m)

> 30

≤ 30

2.10

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

Pipelines/sewers

For pipelines/sewers with total length ≤ 1.000m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.

2.10.1 Water supply pipelines (raw or clean water)

≥ 800

hoặc

≥ 0.51

400 ÷ <800

hoặc

0.13 ÷ < 0.51

150 ÷ <400

hoặc

0.02 ÷ <0.13

<150

hoặc

<0.02

2.10.2 Rainwater drainage sewers, common sewers

Inner diameter of sewers (mm)

Cross-section area of inner sewer (m2)

≥ 2,000

≥ 3.14

1,500 ÷ <2,000

1.77 ÷ <3.14

600 ÷ <1,500

0.28 ÷ <1.77

<600

<0.28

2.10.3 Wastewater drainage sewers

≥1,000

≥0.79

600 ÷ <1,000

0.28 ÷ <0.79

200 ÷ <600

0.03 ÷ <0.28

<200

<0.03

2.10.4 Sewers, trenches, tunnels (used in: communication, information constructions; technical tunnels in factories)

For sewers, trenches, tunnels with total length ≤ 1.000 m: Lower construction classes determined according to this Schedule by 1 but no lower than class IV.