What Is a Built Environment?

The built environment refers to the fact that no building exists in isolation. It exists in various natural and man-made environments. The purpose of building a building is to provide ideal social, economic, political and cultural activities place. Buildings are closely related to the surrounding environment. The surrounding environment is both a constraint and a promotion factor for the building. Therefore, one must seriously consider the role that the environment around a building can play.

First explain the built environment. The environment usually refers to the air environment of a building. The air environment affects people's lives in four aspects, usually referred to as "four degrees," which means air temperature, air humidity, air cleanliness, and air speed and wind speed. Air temperature is the most direct environmental factor that people feel. People feel hot when the temperature is high in summer, and people feel cold when the temperature is too low in winter. This requires changing the temperature of the environment to ensure normal production and living activities. Air humidity is also a direct factor affecting people's lives. In summer, when the humidity is too high, people will feel very hot. In winter, when the humidity is too low, people will have dry lips. Industrial production also requires humidity. For example, textile mills require a constant temperature and humidity environment. Too high or too low humidity will affect the quality of the product. Cleanliness has an impact on human health and the level of technological production. On the one hand, it is necessary to exclude pollutants in the indoor environment. On the other hand, for some factories and laboratories with special requirements, such as precision instruments and electronic products, it is necessary to control the particulate matter and suspended matter in the air to ensure product quality. ^[2]

There are many disturbances that affect the hot and humid environment, air quality environment, light environment and acoustic environment in the building. As with the aforementioned analysis of the hot and humid environment, they can be divided into internal and external disturbances. When carrying out a comprehensive analysis of the built environment, we must not only consider the internal and external disturbances of the building's internal environment, but also consider that the construction of the internal environment of the building will also exert a reaction force on the external environment of the building, thereby affecting or even destroying the external environment. The environment, the internal and external environment of the building both promote and interfere with each other. Therefore, the comprehensive evaluation of the built environment should consider not only the influence of various factors of the internal environment of the building on people, but also the external environment and the natural environment due to the construction of the built environment. And effect.

The building environmental evaluation is actually an evaluation of the building environmental quality, also known as a building environmental quality assessment (Building Environmental Quality: Assessment). The built environment assessment is a qualitative and quantitative description and description of the built environment quality according to certain standards and methods. Through the evaluation of the built environment, we can not only judge the quality of the built environment, but also further understand the quality of the built environment, determine the relationship between the built environment and the ideal environmental goals that people want to achieve, and protect and improve the environment. It meets the requirements of people's work and life, and is conducive to the sustainable development of regional and global environments.

There are many classification methods for building environmental assessment, and there are usually the following classification methods.

1. Classified according to the built environment elements

The building environmental assessment is divided into building thermal and wet environment assessment, air quality assessment, building acoustic environment assessment, and building light environment assessment. These are usually called single-factor assessments; if two or more elements are evaluated simultaneously, they are called Multi-factor evaluation; if all elements are evaluated simultaneously on the basis of single-factor evaluation, it is called a comprehensive evaluation of the quality of the built environment.

2. Classification by evaluation method

The built environment assessment includes two parts: subjective assessment and objective assessment. Subjective evaluation is the use of human sensory organs for description and evaluation, and its connotation expresses the perception of environmental factors and the impact of the environment on health. These evaluations can be standardized and quantified using questionnaires that are internationally applicable and amended according to the actual conditions of each country and region to extract the maximum amount of information and strengthen the reliability of evaluation data. The objective evaluation is to directly use the pollutant indicators of the built environment and the requirements to be met by the environment to evaluate the quality of the environment.

3. Different classification according to evaluation stage

The evaluation of the built environment can be divided into the evaluation of new buildings and the evaluation of existing buildings, that is, the evaluation before the building is put into use and the evaluation during the use of the building. ^[3]

According to the subjective and objective evaluation results, the analysis of the degree and mode of various disturbances (internal and external disturbances) that affect the built environment is an important part of the comprehensive analysis of the built environment. External disturbance generally includes: outdoor air temperature, humidity, solar radiation, wind speed, wind direction, nearby objects of the building (such as trees, other buildings, etc.), surrounding environmental noise, and atmospheric air quality. Internal disturbance generally includes: heat dissipation and dissipation of indoor lighting devices, equipment and personnel, noise generated by indoor equipment and personnel, indoor lighting, gas released from interior decoration materials, smoke and dust generated by smoking, etc.

1.Influencing factors of indoor thermal comfort environment

In a thermally comfortable environment, the dry-bulb temperature, humidity, speed, and radiant temperature of the inner surface of the air are directly related to the thermally comfortable environment of the human body. The internal and external disturbances such as indoor lighting, heat dissipation and humidity of people and equipment, and outdoor meteorological parameters exchange heat and humidity with the air around the human body through heat exchange forms such as convection, radiation, and evaporation, which directly affect the air related to the human thermal comfort environment. Dry bulb temperature, humidity, speed, and radiant temperature of the inner surface. The purpose of room heating and air conditioning is to use engineering methods to overcome these various disturbances from indoor and outdoor, and create indoor hot and humid environments and air conditions that meet people's comfort requirements or process requirements. In the built environment, the first thing people can grasp and control freely is the amount of disturbance that affects the thermal comfort environment.

2.Influencing factors of indoor air environment quality

In the air quality environment, indoor air pollutants are the main factors affecting indoor air quality. In particular, those low-concentration pollutants that are difficult to detect with instruments may undergo physical and chemical reactions with each other under a certain indoor temperature and humidity environment, thereby generating comprehensive effects such as intensification, neutralization, and confrontation. According to investigations, some air pollutants have no obvious source of pollution indoors, but their concentrations are very high, especially when the doors and windows are open in summer or the location of the fresh air inlet of the air conditioner is inappropriate. These pollutants often originate from the outdoor atmosphere. Outdoor pollution sources can be roughly divided into two categories: industrial and transportation pollutants and secondary pollutants, such as SO ₂ , TSP, CO, and O ₃ ; and the other is plants that are prone to cause allergic reactions. In addition, it must be noted that among the many sources of indoor air pollutants, in addition to indoor fuel combustion, smoking soot, people s breathing, metabolic exhaust gases, and released gases from indoor decoration materials, there are also residuals in the air-conditioning equipment when the air-conditioning system is installed. Garbage, waste, bacteria and other pollution caused by improper operation and management of air-conditioning system, these pollutants are brought into the room with the air-conditioning supply air, and become a new indoor pollution source.

3.Influencing factors of indoor light environment

Appropriate indoor illumination and brightness, its reasonable distribution, pleasant light color, and effective anti-glare are the basic elements of a comfortable light environment. There are many factors that affect the comfort of the light environment. The factors from the interior can be roughly attributed to three aspects: improper lighting design, poor quality and maintenance of lighting equipment, and unharmonious optical characteristics of indoor lighting. The distance between buildings is too small, and the neighboring buildings will interfere with each other in terms of light and vision. With the rise of glass curtain wall buildings, the glare reflected light from the surrounding building glass will also damage the indoor light environment and cause light pollution. The main influencing factors from the outdoors. In addition, the stability of indoor lighting voltage and the quality of lighting appliances will also affect people's visual environment.

4.Influencing factors of indoor acoustic environment

The influencing factors of the building acoustic environment mainly come from indoor and outdoor noise. Building environmental noise, ie outdoor noise, includes transportation noise, industrial machinery noise, building construction noise, social life and public place noise, etc. In addition, indoor equipment noise all aggravates the building noise. Environmental pollution. The "Environmental Noise Pollution Prevention and Control Law of the People's Republic of China" enacted by China calls environmental noise pollution a phenomenon that exceeds national environmental noise emission standards and interferes with the normal life, work, and study of others. However, in a fully enclosed building, solid noise such as air noise and equipment vibration caused by fan and airflow of the air conditioning system often affects people's physical and mental health in a low frequency form, non-exceeding order of magnitude.