Interpretation of the provisions regarding doors and windows in GB 55016-2021 General Building Environment Code
2026-05-27
Life cycle cost
Of course, windows are an important component of a building in terms of their cost. The initial investment costs for windows are usually higher than for opaque building envelopes of the same area, but demand or subjective requirements for certain types of windows often do not need to be justified. However, the more important question is how to justify the additional cost of increasing the glass area and using high-efficiency windows. The operating energy consumption and maintenance costs of a building typically exceed the initial investment costs by more than ten times. Moreover, the costs of construction for residents are many times higher than the costs during the operation of the building. The initial cost of windows influences many decisions, but compared to other aspects it is only a small part.
Because windows have a significant impact on building operating costs and the health, productivity and well-being of occupants, it is necessary to use a life cycle approach when selecting and designing windows. Life cycle analysis includes the impact of architectural design and material selection on economics, the environment, and human well-being. Window frames, glazing and sealants all have different service lives, so durability is a key factor in any life cycle analysis. However, windows typically have a life expectancy of 20–30 years and are more expensive and difficult to replace than other building systems, so maintaining energy efficiency throughout the life of the windows is also a fundamental aspect of their longevity.
Article 5.4 of the national standard "Acoustic Environment Quality Standard" GB 3096-2008 states: for sudden noise at night in various functional zones of the acoustic environment, the amplitude of the excess of the maximum sound level over the environmental noise limit value should not exceed 15 dB (A).
The environmental noise limits in Table 1 represent the equivalent continuous sound level A, which is the average sound energy over a specified period of time.
The areas corresponding to the different functional zones of the acoustic environment in Table 1 are shown below:
The functional zone of the acoustic environment of category 0 refers to areas that require special silence, such as medical and recreational areas.
The functional zone of the acoustic environment of the 1st category is an area whose main purpose is residential buildings, medical and health institutions, cultural and educational facilities, research and design organizations, as well as administrative offices; These are areas that require maintaining silence.
The functional zone of the acoustic environment of the 2nd category is an area whose main purpose is commercial and financial activities and market trade, or areas of mixed residential, commercial and industrial development, where it is necessary to ensure silence in residential premises.
The functional zone of the acoustic environment of the 3rd category is an area whose main purpose is industrial production, warehouse and transport logistics; These are areas where it is necessary to prevent serious environmental impacts from industrial noise.
The functional zone of the acoustic environment of the 4th category is an area within a certain distance on both sides of the main transport routes, where it is necessary to prevent the serious impact of transport noise on the environment; includes two subtypes: 4a and 4b. Category 4a covers areas along expressways, first and second class highways, urban express roads, major and minor urban arterial roads, urban rail lines (ground sections) and inland waterways; Category 4b covers areas along mainline railways.
In the functional zones of the acoustic environment of categories 2 and 3, industrial facilities are located, and zones of category 4 are territories within a certain distance on both sides of the main transport routes. Environmental noise and vibration levels in these areas can be high. Surveying and measuring noise and vibration at a civil building site before construction allows designers to take appropriate engineering measures to ensure that the building's interior meets noise and vibration standards.
Appendix A Classification of functional zones of the acoustic environment
A.0.1 The classification of functional zones of the acoustic environment must comply with the provisions of Table A.0.1.
| Categories of functional areas by noise level | Zone Characteristics |
| Category 0 | Applies to areas that require special silence, such as medical and recreational areas |
| Category 1 | Refers to areas whose main function is residential development, medical care and healthcare, culture and education, research design, administrative management, and where silence is required |
| Category 2 | Applies to areas whose main function is commerce and finance, market trade, or mixed residential, commercial and industrial areas where it is necessary to maintain quiet in residential areas |
| Class 3 | Refers to areas where the main function is industrial production, warehousing and logistics, and where it is necessary to prevent serious impacts of industrial noise on the environment. |
| Class 4 | Refers to areas within a certain distance on either side of main traffic routes where it is necessary to prevent serious impacts of traffic noise on the environment; includes two types: 4a and 4b. Category 4a includes areas along expressways, first and second class highways, urban express roads, major and minor urban highways, urban rail lines (land sections) and inland waterways; Category 4b includes areas along main railway lines. |
Article
2.1.3 Noise limit values and conditions for their application when propagating from external noise sources into the main functional rooms of buildings must comply with the following provisions:
1 Limit values for noise penetrating from external sources into the main functional rooms of buildings must comply with the provisions of Table 2.1.3;
Note: 1. If the building is located in a functional acoustic environment zone of class 2, class 3 or class 4, the permissible noise level can be reduced by 5 dB; 2. The permissible noise level at night must be the equivalent sound level Lae measured continuously at night; 3. If the equivalent sound level Lae after 1 hour cannot reflect the noise level for the entire period, the measurement period can be 1 hour.
2. Noise limits must correspond to the values with doors and windows closed;
3. The day period is considered to be the time from 6:00 to 22:00, the night period is from 22:00 to 6:00 the next day. If local regulations establish a different division between daytime and nighttime, these regulations should be followed.
Explanation
Factors influencing the noise level inside the main functional areas of a building are mainly divided into two categories: the first is external noise sources entering the premises through the building envelope; the second is the vibration and noise created by engineering equipment inside the building itself. This article mainly sets limits for noise entering premises from external sources. Reducing the influence of such sources on the main functional premises is achieved mainly by increasing the sound insulation characteristics of the external building envelope.
Nowadays, situations often arise when residential buildings, hotels, schools, offices and other civil buildings are exposed to noise, which leads to conflicts, disputes and even lawsuits. Thus, establishing limit values for noise levels inside premises of various functional purposes makes it possible to ensure an appropriate acoustic environment in them, and also provides a regulatory framework for specialists in the field of design, construction, technical supervision, acceptance, administrative management and judicial arbitration.
This article establishes limit values for noise levels indoors for various functional purposes. Typical examples of premises for various purposes:
Rooms intended for sleeping, such as bedrooms;
Rooms intended for daily activities, such as living rooms;
Rooms intended for reading, self-education and reflection, such as reading rooms;
Spaces used for teaching, medical care, office work, and meetings, such as classrooms, examination rooms, offices, and conference rooms.
The noise limits set forth in this article are equivalent sound levels that should not be exceeded when measured inside the relevant premises, taking into account only external noise sources. When carrying out measurements, interference from other noise sources should be excluded. The method for measuring equivalent sound level shall be in accordance with Annex A of the national standard Code for the Design of Sound Insulation for Civil Buildings GB 50118-2010.
This code sets indoor noise limits when windows are closed. With the increasing number of outdoor noise sources and high levels of external noise (especially near urban transport routes, highways, railways and airports), it is difficult to ensure low noise levels indoors with open windows. To reduce the impact of external noise on premises, the main effective architectural solution is to increase the sound insulation capacity of window structures. While closing windows reduces the impact of outside noise, it also stops air circulation between indoors and outdoors, making it difficult to maintain fresh air. Therefore, when planning and designing civil buildings, noise protection measures should, whenever possible, be taken at the level of planning decisions, striving to ensure that even with open windows, the noise level in the premises complies with the requirements of this code.
According to the Law of the People's Republic of China on the Prevention and Control of Noise Pollution, daytime refers to the period from 6:00 to 22:00, and nighttime refers to the period from 22:00 to 6:00 the next day. Due to China's vast territory and multiple time zones, some local governments set different rules for dividing daytime and nighttime to accommodate local time differences and daily routines. In such cases, the times corresponding to the day and night periods shall be determined in accordance with the regulations of the local people's governments.
Article
3.2.1 The design of natural lighting should determine the illumination class in accordance with the architectural features and functional purpose of the building.
Explanation
This paragraph establishes general principles and basic requirements for the design of natural lighting. The effective depth of natural light and the corresponding window to floor area ratio for various illuminance classes are given in Table 2 for reference but should not serve as the sole basis for design.
Article
3.2.7 The color rendering index of light openings in the main functional rooms must be at least 80.
Explanation
Compared to artificial lighting, the color rendition of natural light is one of its main advantages. When designing lighting, in addition to providing quantitative indicators (i.e. increasing the efficiency of the system), attention should be paid to the quality of lighting, an important indicator of which is color rendering. The color rendering index is usually used as an evaluation indicator. According to CIE assessment standards, it is divided into levels 90, 80, 60 and 20; The color rendering of natural lighting systems must reach an excellent level. Color rendering index testing can be carried out in accordance with the provisions of the current national standard GB/T 11976 "Classification and test methods for lighting performance of external windows of buildings".
* The use of 2-chamber or 3-chamber double-glazed windows in energy-saving windows, as well as glass with Low-E or heat-reflective coating, affects the color rendering index of the window. Energy saving and window color rendering index are conflicting factors. Since this provision limits the scope of application to the main functional areas, color rendering index should be considered as a priority factor in the design and ensured first.
Article
3.2.8 When installing glass curtain walls in buildings, the following requirements must be met:
1 When installing glass curtain walls in residential areas, near hospitals, primary and secondary schools, kindergartens, as well as at highway intersections and in areas with heavy traffic, an analysis of the influence of reflected light from glass facades should be carried out;
2 In places where people stay or work for a long time, the time of continuous exposure to light reflected from glass facades on the surface of the window sills should not exceed 30 minutes;
3. Within a vertical angle of 20°, a horizontal angle of ±30° in the direction of travel of the driver and at a distance of 100 m, glass curtain walls shall not create continuous harmful reflections of light to vehicle drivers.
Explanation
Harmful light reflection from glass curtain walls is a form of light pollution, and the glare it creates can cause discomfort. If there are glass curtain walls in the surrounding space, the time of continuous exposure to reflected light on the window sills of buildings in the angle range from 0° to 45° to the horizontal plane should not exceed 30 minutes. At the same time, the influence of reflected light from glass curtain walls on drivers should be avoided to reduce the likelihood of traffic accidents. The reflected light effect of glass curtain walls can be calculated using appropriate software.
Places of long-term stay or work are the main functional premises for study, work and living, with the exception of corridors, staircases, lobbies, elevator halls, bathrooms, etc.
Article
3.4.3 When installing outdoor night lighting, its impact on residential premises must comply with the following provisions:
1. Vertical illumination on the outer surface of windows of residential premises should not exceed the values specified in table 3.4.3-1.
Note: * If there is public (road) lighting, this value increases to 1 lux.
Explanation
The effect of lighting on occupants is usually related to the vertical illumination created on windows by outside light entering dark living spaces; This article aims to limit the amount of light entering the room. In addition to vertical illumination on the window surface, another factor affecting occupants is glare from luminaires that are directly visible, so the intensity of light from luminaires towards residential windows should be limited.
Article
4.4.4 The roof, floor, external walls and external windows must prevent rainwater and melt water from entering the premises.
Explanation
Waterproofing is the main function of the building envelope.
The building envelope, such as the roof, floors, external walls, windows, etc., must prevent the penetration of rain and melt water into the premises in order to protect the internal equipment of the building from the effects of rain and snow and ensure normal operation of the building.
*This item is presented for the first time as a mandatory provision in regulations relating to doors and windows.
Article
5.1.1 Control of pollutants in indoor air should be carried out by taking measures in the following order:
1. Monitoring the influence of radon concentration in the soil at the building site on indoor air quality;
2 Control of the spatial layout of the building to facilitate the removal of pollutants;
3 Monitoring that the volume of emissions of harmful substances from the main structures of the building, materials for energy-saving works and finishing materials corresponds to the established limit values;
4 Taking measures for natural ventilation to improve indoor air quality;
5 Installation of mechanical ventilation and air conditioning systems, and, if necessary, installation of air purification devices to control the content of pollutants in the air.
Explanation
This article establishes the basic principles for the control of indoor air pollutants and determines the priority order of measures taken to control air pollution in civil buildings.
The main purpose of buildings is to provide conditions for people to work and live, so throughout the entire life cycle of construction it is necessary to prevent or minimize the harmful effects of air pollutants on human health and safety. This code of practice establishes mandatory limit values and technical measures for the main pollutants emitted by the building structures themselves. At the same time, to ensure that hygienic requirements for air quality during the operation of buildings are met or exceeded, in addition to controlling emissions from materials, technical requirements are put forward for the use of active means such as ventilation and air purification.
The choice of specific measures - the use of a large volume of fresh air or the use of recirculation air purification systems - should be based on a comprehensive analysis taking into account energy saving requirements. The corresponding requirements for ventilation and air purification must comply with the provisions of the current state standard “General Standards for Heating, Ventilation and Air Conditioning in Civil Buildings” (under development).
