Foreword

TCVN 4451:2012 replaces TCVN 4451:1987.

TCVN 4451:2012 was converted from TCVN 4451:1987 in accordance with clause 1, Article 69 of the Law on Standards and Technical Regulations and point b), clause 1, Article 6 of Decree No. 127/2007/ND-CP dated August 01, 2007 of the Government detailing the implementation of some articles of the Law on Standards and Technical Regulations.

TCVN 4451:2012 was drafted by the Institute of Architecture, Urban and Rural Planning, proposed by the Ministry of Construction, reviewed by the General Department of Standards, Metrology and Quality, and promulgated by the Ministry of Science and Technology.

1. SCOPE

1.1. This standard applies to the design of new or renovated apartment buildings (residential apartments), dormitories constructed in cities, towns, townships or residential areas of agencies, enterprises and schools.

NOTE: Apartment buildings and dormitories are hereinafter referred to as residential buildings.

1.2. This standard may be applied to old residential buildings managed by the state when repairing, and privately built residential buildings within the inner-city and inner-town areas.

1.3. When designing residential construction in farm and forest settlements, the provisions on living area, hygiene and safety in this standard must be complied with. The area of auxiliary works may be designed according to separate provisions to suit the specific requirements of each locality.

2. REFERENCES

The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

TCVN 2622, Fire prevention and protection for buildings and structures – Design requirements;

TCVN 4474, Indoor drainage – Design standard;

TCVN 4513, Indoor water supply – Design standard;

TCVN 4450, Residential apartments – Design requirements;

TCVN 5687:2010, Ventilation – Air conditioning – Design standard;

TCVN 6772:2000, Water quality – Domestic wastewater – Permissible limit of pollution;

TCVN 9210:2012, High-rise residential buildings – Design standard;

TCVN 9385:2012¹⁾, Lightning protection for buildings – Guidelines for design, inspection and maintenance of system;

TCVN 9386-1÷2:2012¹⁾, Design of earthquake resistant structures;

TCXD 16:1986²⁾, Artificial lighting in civil works;

TCXD 29:1991²⁾, Natural lighting in civil works – Design standard;

TCXDVN 377:2006²⁾, Central gas supply system in residential buildings – Design standard;

TCXDVN 387:2006²⁾, Central gas supply system in residential buildings – Construction and acceptance standard.

3. TERMS AND DEFINITIONS

For the purposes of this standard, the following terms and definitions apply:

3.1. Residential apartment

A living space for a family, an individual or a group, meeting the living needs of a family, a group as well as each member.

3.2. Apartment building

A residential building of two or more stories, with shared corridors, staircases and infrastructure system for many family and individual apartments.

3.3. Above-ground floor

A floor whose slab level is higher or equal to the ground elevation at the construction site according to the approved planning.

3.4. Basement

A floor whose height is more than half below the ground elevation at the construction site according to the approved planning.

3.5. Semi-basement

A floor whose height is half above or equal to the ground elevation at the construction site according to the approved planning.

3.6. Attic floor

A floor located within the sloped roof space, entirely or partly bounded by the inclined or folded roof surface, in which the vertical wall (if any) does not rise above the floor by more than 1.5m.

3.7. Story height

The story height is the distance between two floors, measured from the lower floor to the next floor.

3.8. Clearance height

The height from the finished floor to the underside of the load-bearing structure or finished ceiling of that story.

3.9. Living room

Rooms in an apartment used independently or in combination with other functions. Living rooms include bedrooms, common living rooms, guest rooms, study rooms, dining rooms, etc.

4. GENERAL PROVISIONS

4.1. Residential buildings shall be designed according to the type and grade of the construction as specified in the classification of civil works [1].

4.2. The design of residential buildings must ensure the durability, safety, and comfort of the construction, suitable to the climatic and natural conditions, customs and habits, meeting the requirements on life safety and health [2], ensuring accessibility and usability for persons with disabilities in accordance with current regulations.

4.3. When a technical floor is designed under the foundation of the first floor or the ground floor (in the basement), the clearance height of the technical floor must not be less than 1.6 m and must have direct access to the outside by a door or a wall opening with a cover not less than 0.6 m x 0.6 m.

4.4. When the height of a semi-basement, an attic floor, including above-ground floors, measured from the ground elevation according to the approved planning to the finished ceiling is not less than 2 m, it is considered a story of the building.

NOTE: The ground elevation according to the approved planning is the sidewalk elevation defined as elevation ± 0,000 at the location of the building for calculating the permitted height of the building.

4.5. When designing spaces for installing air conditioning equipment or drying clothes, it is necessary to ensure that it does not affect the facade architecture of the construction and environmental hygiene. The space for air conditioning should have a standardized location and size to ensure aesthetics.

4.6. Depending on specific requirements, garbage collection rooms can be designed at each floor or a garbage chute can be arranged for the building.

4.7. The exterior of the building must not use colors or materials that adversely affect human vision and health. Ensure conditions of security, noise, visibility, landscape and environmental hygiene.

4.8. Advertising signs attached to apartment buildings must comply with relevant regulations on advertising.

4.9. The division of area in residential buildings is specified in Appendix A of this standard.

4.10. The method for determining the volume factor and floor area ratio of residential buildings is specified in Appendix B of this standard.

4.11. When designing apartment buildings and dormitories, in addition to complying with the provisions of this standard, it is necessary to comply with the provisions of TCVN 4450 and TCVN 9210:2012.

5. REQUIREMENTS FOR CONSTRUCTION LAND AND GENERAL SITE PLANNING

5.1. The land for residential construction must ensure the following basic principles:

• Conform to the approved construction planning;
• Have a synchronous technical infrastructure and social infrastructure system, meeting current and future development requirements;
• Not be located in prohibited construction areas; protection corridors of transport, irrigation, dike, energy, historical – cultural relics and other protected areas as prescribed by law; areas with risk of landslides, flash floods, inundation, contaminated by industrial waste, landfills, cemeteries.
• Ensure safety of fire and explosion prevention and environmental hygiene.

5.2. When designing residential buildings, it is necessary to take into account the flexible usability, depending on the structure of the apartments, the location on the construction site, the architectural space to design appropriately with the requirements of urban construction [3].

5.3. The orientation of the building should be selected as the direction where the windows of living rooms open to receive cool breeze or natural light. In an apartment building, at least a number of rooms must face the prescribed direction:

• Apartments with 2 and 3 rooms: 1 room;
• Apartments with 4 rooms or more: 2 rooms;

In a dormitory: at least 40% of the living rooms must have an external exposure.

NOTES:

1) The prevailing wind direction is determined according to natural climatic data used in construction [4].

2) For living rooms with an unfavorable orientation, shading measures should be taken.

6. ARCHITECTURAL DESIGN REQUIREMENTS

6.1. The floor elevation at the building entrance must be at least 0.15 m higher than the curb elevation at the entrance.

6.2. Living rooms must be located on above-ground floors. When a residential building is constructed adjacent to the red-line boundary, the ground floor elevation of living rooms must be at least 0.50m higher than the sidewalk elevation.

6.3. The minimum area of an apartment in an apartment building is:

• 30 m² for social housing;
• 45 m² for commercial housing.

6.4. The minimum living area standard for dormitories for students of universities, colleges, vocational and professional secondary schools is 4 m²/person.

6.5. Living rooms in dormitories can also be combined with other rooms such as foyers, kitchens, and bathrooms.

6.6. In dormitories, a shared kitchen or bathroom can be designed for several living rooms, but not more than 25 people. Public service rooms such as cultural activities, study, sports, rest, public dining, medical service, administration, management should be arranged. The components and area of public service rooms are based on the design requirements.

6.7. Depending on the function and volume requirements of each living room in an apartment or dormitory, the height and width can be designed appropriately.

• The story height must not be less than 3.0 m;
• The clearance height of the room must not be less than 2.7 m;
• The clearance height of the living room in an attic floor must not be less than 1.5 m;
• For living rooms in dormitories using bunk beds, the clearance height must not be less than 3.3m. In this case, the clearance width of the room must not be less than 3.3 m.

6.8. The clearance height of auxiliary rooms must not be less than 2.4 m.

6.9. The height of the technical floor is determined on a case-by-case basis, depending on the type of equipment and system arranged in the technical floor, taking into account the operating conditions.

6.10. The clear depth of the living room measured in the direction of receiving direct natural light (receiving light from one side) must not exceed 6.0 m and must not be greater than twice the width of the living room.

When necessary to suit the modular dimensions, the depth may be increased but not by more than 5%.

6.11. Bathrooms, wash basins, laundry areas, toilets of the upper floor must not be located above the kitchen, storage, food preparation areas of the lower floor.

6.12. The floors of the stories in the residential building must be soundproofed.

6.13. The number of steps on a staircase (stair flight) or winder must not be less than 3 and not more than 18.

6.14. The minimum width of the corridor in a residential building between staircases or between a staircase and the end of the corridor must meet the following requirements:

• When the corridor length is up to 40 m: 1.4 m;
• When the corridor length is over 40 m: 1.6 m.

6.15. Staircases and landings must have enclosing structures and handrails. For residential buildings for the elderly, weak and disabled, additional handrails along the wall must be provided.

6.16. Railings of loggias and balconies of buildings from 3 stories and above must be made of non-combustible materials.

6.17. Loggias and balconies must not be installed with glass for other purposes.

6.18. Residential buildings over 6 stories high must have elevator design. The number and specifications of elevators are calculated to suit the selected design solution.

6.19. The width of the lobby in front of the elevator must meet the following requirements:

• Passenger elevator with 400 kg capacity: 1.2 m;
• Passenger elevator with 630 kg capacity and elevator car dimensions (2100 mm x 1100 mm): 1.6m;
• Elevator car dimensions (1100 mm x 2100 mm): 2.1 m.

NOTE: The elevator car dimensions are measured in width x depth.

6.20. The elevator shaft must not be located adjacent to living rooms.

6.21. When a residential building faces a street or a square, it is allowed to arrange on the first floor (ground floor) or basement, semi-basement shops, supermarkets, public dining services, stores, management rooms of the residential area, gym under 150 m², public activity rooms. In this case, it is necessary to ensure fire prevention requirements, sound insulation and prevention of odor pollution to the residential area by appropriate technical solutions. When stores or supermarkets are arranged in or adjacent to a residential building, entrances to the building must not be designed directly from the goods delivery yard.

6.22. The following must not be arranged in a residential building:

• Pump station and boiler;
• Power substation inside or adjacent to the building;
• Automatic telephone exchange, except for telephone exchange serving the building;
• Administrative headquarters of all levels;
• Medical examination rooms, except for gynecology and dental examination;
• Dining rooms, cafeterias over 50 seats;
• Public toilets;
• Components that generate noise, sound, toxic fumes and hazardous waste exceeding permissible limits;
• Stores selling construction materials, chemicals, miscellaneous goods that when operating cause environmental pollution around the residential building;
• Stores selling flammable and explosive materials;
• Public baths, saunas, laundries and chemical cleaners (except for clothes receiving points and self-service laundry facilities).

6.23. The following must not be arranged under living rooms:

• Hot water boilers of the hot water supply system for the building;
• Cold rooms of commercial enterprises and public services.

6.24. When designing residential buildings in seismic zones, the provisions of TCVN 9386-1÷2:2012 must be complied with.

7. REQUIREMENTS FOR TECHNICAL SYSTEMS

7.1. Water supply and drainage design requirements

7.1.1. The design of water supply and drainage systems for residential buildings must comply with the provisions of TCVN 4474 and TCVN 4513.

7.1.2. The distribution network of the internal water supply pipeline must be buried in the wall or in technical boxes. Valves installed in buried trenches or technical boxes must have inspection doors for convenient management and repair.

7.1.3. Water supply and drainage pipes must not be allowed to be exposed under the ceiling of rooms.

7.1.4. The wastewater treatment system must be designed to ensure the wastewater quality according to TCVN 6772:2000 before flowing into the regional drainage system.

7.1.5. A rainwater drainage system must be designed on the roof to ensure rainwater drainage in all weather conditions of the year. The vertical rainwater drainage pipes must not be allowed to leak, must be arranged not to affect the architectural aesthetics and must be connected to the building’s drainage system.

7.2. Ventilation and air conditioning system design requirements

7.2.1. Natural ventilation for living rooms must be fully utilized. Natural ventilation must not be solved for living rooms through kitchens, wash basins, laundry, bath, toilets and storage. Design of ventilation and air conditioning systems shall be in accordance with TCVN 5687:2010.

7.2.2. Toilets, urinals, bathrooms, if not directly naturally ventilated, must be artificially ventilated.

7.2.3. The location of air conditioning installation, exhaust air ducts and condensate drains must be arranged at positions that do not affect the surrounding apartments and affect aesthetics and environmental hygiene.

7.3. Lighting and electrical equipment system design requirements

7.3.1. Artificial and natural lighting systems shall be designed according to TCXD 16:1986 and TCXD 29:1991.

7.3.2. Natural lighting should be prioritized in the following places: living rooms, kitchens, sanitary areas, foyers, general staircases, common corridors, public activity rooms in dormitories. For bathrooms, wash basins, laundry rooms, toilets, urinals, storage, direct natural lighting is not necessarily required.

7.3.3. The ratio of illuminated window area of all living rooms, kitchens, compared to the floor area of the above areas shall not be greater than 1:5, at the minimum, not less than 1:8.

7.3.4. The method for calculating the area of lighting openings is referenced in Appendix C.

7.3.5. When lighting through window openings on the end walls, the length of the common corridor is 24 m and the length of the two ends is 48 m.

If the corridor is longer than the above values, additional natural lighting needs to be designed through a light well. The distance between two light wells shall not exceed 24 m. The distance between the light well and the lighting window at the end of the corridor shall not exceed 30 m.

If the corridor is shorter than 10 m, lighting can be provided through the stairwell or the doors of auxiliary rooms arranged along the corridor.

NOTES:

1) The width of the light well must be greater than 1/2 the depth of the well measured from the exterior wall to the edge of the corridor.

2) When using stairwell windows for supplemental lighting, the ratio of the stairwell floor area must be greater than 1/6.

7.3.6. The power supply from the floor cabinets and panels to the panel of each apartment must use wire lines or power cables along the corridor and buried in the wall. In case of surface mounting, wires must be threaded through fire-resistant plastic or steel conduits.

7.3.7. The lighting system in the apartment is protected by circuit breakers. The number of sockets in a room shall not be less than 2. Electrical sockets and junction boxes installed in bathrooms and kitchens must have current interrupting devices and must be placed at appropriate locations and heights. For safety, all switches and sockets connected to the power source must be protected by an earth leakage circuit breaker.

7.3.8. In apartment buildings, electricity meters must be installed for each apartment. In dormitories, electricity meters must be installed for each room or each module.

7.3.9. The design of the lightning protection system must comply with the provisions of TCVN 9385:2012.

7.4. Communication and telecommunications system design requirements

7.4.1. The design and installation of communication, broadcasting, television systems for residential buildings must ensure safety, convenience for exploitation and use and connection with service systems of the provider, and at the same time must ensure replaceable, repairable capability and have a minimum distance to other technical pipelines.

7.4.2. The design and installation of communication, broadcasting, television systems must comply with relevant regulations.

7.4.3. Communication and television cable systems need to have pre-buried conduits in the walls. At each floor, junction boxes need to be arranged.

7.4.4. The broadcasting and television network system from the distribution cabinet to the apartments must go underground in technical boxes, and at the same time, there must be lightning protection solutions for the receiving antennas.

On the roof of the residential building, it is allowed to arrange antennas, receiving and transmitting dishes for broadcasting and television at the location permitted by the urban management agency and ensure safety and aesthetics according to relevant regulations. When necessary, television signal receiving equipment may be arranged on the attic floor.

7.5. Gas supply system design requirements

7.5.1. When there is a need to install a gas supply system in a residential building, it must comply with TCXDVN 377:2006 and TCXDVN 387:2006.

7.5.2. When designing and installing a gas supply system, it is necessary to ensure the technical parameters of pipelines, supports, measuring devices, safety devices, specifications, installation space of equipment and must have solutions to prevent corrosion of equipment and pipelines.

7.5.3. Do not design main supply pipes or risers through bedrooms, bathrooms, toilets or waste storage rooms.

7.5.4. Kitchens using gas must have smoke exhaust vents. The volume of the kitchen must ensure sufficient air for the natural combustion process.

8. FIRE PREVENTION REQUIREMENTS

8.1. Residential buildings must not exceed the allowable limits on fire resistance rating, number of stories, length, and construction area as specified in Table 1.

Table 1 – Regulations on fire resistance rating, number of stories, length, construction area

8.2. The maximum distance from the entrance of a living room to the nearest stairwell or exit is specified in Table 2.

Table 2 – Maximum distance from living room door to the nearest stairwell or exit

Dimensions in meters

8.3. The total width of staircases and passages on the escape route of the building, calculated according to the number of people on the most populous floor, excluding the 1st floor, is specified as follows:

• For a two-story residential building: 1.00 m width for 125 people;
• For a residential building of three stories or more: 1.00 m width for 100 people;
• When the number of people on the most populous floor is below 125 (for 2-story buildings) or below 100 (for 3-story buildings or more), the total width is taken as 0.90 m.

8.4. The width of each stair flight on the escape route must ensure to be equal to or greater than the minimum stair width. The slope must be less than the maximum slope specified in Table 3.

8.5. It is necessary to design an automatic fire alarm system to notify everyone when there is a fire.

8.6. In addition to the above provisions, the design of residential buildings must also comply with the fire safety regulations for buildings and structures [5] and TCVN 2622.

Table 3 – Regulations on stair width and slope

8.7. The minimum allowable clear width of escape routes is specified in Table 4.

Table 4 – Minimum clear width of escape routes

Dimensions in meters

APPENDIX A (REGULATION) AREA DIVISION IN RESIDENTIAL BUILDINGS

A.1 The usable area of each apartment is the total of the living area and the private auxiliary area. For multi-apartment residential buildings, the usable area of each apartment is the private usable area of each apartment plus the portion of shared auxiliary area allocated according to the ratio of the living area of each apartment.

A.2 The areas of rooms and components are all calculated according to the clear dimensions (excluding the thickness of walls, partitions, columns including plaster but not excluding the thickness of wall base or wall cladding materials).

The area of rooms with lower ceiling height is included in the total area with a factor of 0.7.

NOTE: Garbage chutes, chimneys, ventilation, electrical, water and other technical ducts located in a room or component are not included in the area of those rooms or components.

A.3 The usable area in a residential building is the total area of the living rooms and auxiliary rooms, calculated as follows:

a) The living area is the total area of the main living rooms including:

• Living rooms (bedrooms, common living rooms, guest rooms, study rooms, entertainment rooms) in an apartment;
• Living rooms, bedrooms in a dormitory;
• Wardrobes, built-in cabinets, hidden cabinets with doors opening inwards to the living room;
• The area under the stairs arranged in the living rooms of the apartment (if the height from the floor to the underside of the stairs is less than 1.60 m, this area is not included).

b) Auxiliary area: is the total area of the following auxiliary rooms or components:

• Guest rooms, common living rooms, management rooms in dormitories;
• Kitchen (cooking, washing, processing, preparation area) excluding the area occupied by chimneys, garbage chutes, supply and drainage pipes;
• Bathrooms, laundry rooms, toilets, urinals and interior passages for residential buildings designed with centralized sanitary areas;
• Storage;
• Half of the loggia area;
• 0.3 of the balcony and porch area;
• 0.35 of the roof terrace area;
• Corridors and passages of the apartment or living rooms;
• Vestibules, anterooms, etc. used privately for one apartment or a few living rooms;
• Passages, entrances, anterooms of centralized kitchen or bathroom, laundry, toilet, urinal areas;
• Built-in cabinets, hidden cabinets of the apartment with doors opening inwards to the auxiliary components or rooms.

NOTE: In multi-apartment residential buildings, the auxiliary area shared by many apartments such as parking rooms, common public activity rooms, management or security rooms is not included in the above area.

A.4 The total usable area of rooms in a dormitory is determined by the total area of living rooms, auxiliary rooms, public service rooms, loggias, balconies, porches. In which loggias, balconies, porches are calculated according to the provisions in A. 3 b).

A.5 The following cases are not included in the total residential area: the area of the basement for ventilation, the attic floor, the attic floor with technical systems, the technical floor, the technical systems outside the apartment, the stairwell vestibule, the elevator shaft, the outdoor stairs.

A.6 The residential area is calculated by the total area of the building floors, within the inner face of the exterior walls, with the area of balconies and loggias. The area of stairs and elevator shafts is included in the floor area of that floor.

A.7 The area of rooms in a residential building is calculated according to the dimensions measured between the separating surfaces of walls and partitions on the floor (excluding wall base moldings). When determining the area of the attic floor, it is calculated as follows:

• Sloped attic ceiling 30o – ceiling height taken as 1.5 m;
• Sloped attic ceiling 45o – ceiling height taken as 1.1m;
• Sloped attic ceiling 60o or more – ceiling height taken as 0.5m.

A.8 The circulation area is the total area of the components used in common by the apartments or living rooms for movement within the building. The areas of the following components are all included in the circulation area:

a) Stairwells, including landings and approach slabs;

b) Corridors used in common by apartments and living rooms;

c) Vestibules, floor lobbies;

d) Outdoor stairs;

A.9 The structural area is the total area of walls, partitions, columns calculated on the plan (horizontal section). The areas of the following components are all included in the structural area:

a) Load-bearing or non-load-bearing walls, partitions, columns;

b) Door thresholds, window sills of all types;

c) Chimneys, ventilation ducts, electrical, water and other technical ducts including the duct cavity and duct walls;

d) Wall niches, gaps between two rooms (without door installation) with a width less than 1.50m and a height less than 1.90m.

NOTE: The structural area is determined by subtracting the living area, auxiliary area, and circulation area of that floor from the floor (slab) area of the floor. If it is the first floor (ground floor), it is the building area minus the living area, auxiliary area, and circulation area.

A.10 Other areas are the total areas of rooms or components not used for living but only for other functional uses of the building such as: dining, drinking, hair cutting, retail stores, parking spaces, public laundry rooms, etc.

A.11 The building area is the area calculated according to the envelope dimensions of the exterior walls, column rows with roof covers, outdoor stairs, steps, walkways, doors, loggias, roof terraces.

NOTE: The building area equals the total living area, auxiliary area, circulation area, structural area and other areas of the first floor.

A.12 The building volume of a residential building is calculated by the total building volume at elevation ± 0.000 (above ground) and below that elevation (below ground).

A.13 The building volume of the building, a building floor, an apartment is the product of the building area of the building, the floor area of the floor or apartment with the height of the building, building floor and each apartment. The height is calculated as specified in 6.8 and 6.9 of this standard.

A.14 Centralized kitchen and sanitary areas, arranged outside the residential building, are not included in the area of the residential building, the areas of these auxiliary works are calculated separately.

A.15 Private ownership and common ownership in apartment buildings.

a) An apartment building is a residential building with two or more floors, with shared corridors, staircases and infrastructure systems for many households and individuals. An apartment building has private ownership of each household and individual and common ownership of all households and individuals using the apartment building.

b) The private ownership in an apartment building includes:

• The area inside the apartment, including the area of balconies and loggias attached to that apartment;
• Other areas in the apartment building recognized as private ownership according to the provisions of law;
• Privately used technical equipment system attached to the apartment and the area belonging to private ownership.

c) The common ownership in an apartment building includes:

• The remaining building area of the apartment building besides the area belonging to private ownership specified in clause 2 of A.15;
• The space and load-bearing structural system, technical equipment used in common in the apartment building, including frames, columns, load-bearing walls, building envelope walls, apartment separating walls, floors, roofs, roof terraces, corridors, staircases, elevators, escape routes, garbage chutes, technical boxes, parking spaces, electricity, water, gas, communication, broadcasting, television, drainage, septic tanks, lightning protection, firefighting systems and other parts not belonging to the private ownership of any apartment;
• The external technical infrastructure system connected to that apartment building.

APPENDIX B (REGULATION) METHOD FOR DETERMINING THE FLOOR AREA RATIO AND PLAN RATIO OF RESIDENTIAL BUILDINGS

B.1 When designing residential buildings, it is necessary to calculate the volume factors: K, K₁, K₂.

B.2 Floor area ratio K, K₁, K₂ are determined as follows:

a) Floor area ratio K is the ratio of living area over building area or living area of the apartment over floor area of the apartment.

K = Living area / Building (floor) area (1)

b) Floor area ratio K₁ is the ratio of living area over usable area of the building or apartment:

K₁ = Living area / Usable area (2)

c) Volume factor K₂ is the ratio of the building volume of the building (apartment) over the living area:

K₂ = Building volume of the building (apartment) / Living area (3)

d) The volume and floor area ratios can fluctuate within the ranges:

K = 0.40 to 0.45

K₁ = 0.48 to 0.55

K₂ = 0.50 to 6.50

APPENDIX C (REFERENCE) AREA AND TYPE OF LIGHTING OPENINGS

C.1 The area of lighting openings is calculated as follows:

a) For windows, take the empty wall space for installing the window;

b) For doors, take the area of the lighting glass space without deducting the frame;

c) For skylights, take the empty space of the skylight when the thickness of the skylight does not exceed 10 cm. If it exceeds 10 cm, take 2/3 of the empty space of the skylight.

C.2 The following openings are included in the lighting area:

a) Windows that directly open to the outside, porches, loggias, balconies or ventilated side corridors (without exterior walls and windows);

b) The glass part of doors when directly opening to ventilated porches, loggias, balconies or corridors.

C.3 The following types of openings are not included in the lighting area:

a) Windows and doors opening towards central corridors, side corridors;

b) Baffles, loggias, voids used for ventilation;

c) Doors separating rooms.

LIST OF REFERENCES

[1] QCVN 03:2009/BXD, National technical regulation on classification and grading of civil, industrial and urban technical infrastructure construction works;

[2] QCXDVN 05:2008/BXD, Vietnam building code – Residential and public buildings – Life and health safety;

[3] QCXDVN 01:2008/BXD, Vietnam building code – Construction planning;

[4] QCXDVN 02:2008/BXD, Vietnam building code – Natural condition data used in construction – Part 1;

[5] QCVN 06:2010/BXD, National technical regulation on fire safety for buildings and structures.

1) TCVN to be promulgated

2) TCXD and TCXDVN being converted.