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«Экономика строительства» № 6 (72) /2021
ЭКОНОМИКА и ЭКОЛОГИЯ
УДК 69.001.5
Ecology of buildings. Analysis and methods of building design
Vaziakov I.A., Principal engineer of technical supervision, Municipal Unitary Enterprise «Capital Construction Management Minsk City Executive Committee», the Republic of Belarus
Keywords: «healthy building», design, air quality, ecology, microclimate, resource conservation.
This article discusses both indoor conditions, especially indoor air quality issues, and general environmental issues. It discusses the assessment of the impact of buildings on the environment as a whole. It also analyzes the available data to determine the norms of important parameters of buildings and analyzes the main studies of the impact of buildings on the health of residents. The analysis presented here is intended to help building designers prioritize alternative design options that minimize harmful effects on the internal and general environment. Also, this document focuses on methodologies for developing design guidelines, rather than detailed recommendations that may lead to this. The publication discusses design issues related to indoor air quality and «sustainable architecture». The emphasis here is on the study of analytical methods and sources for the development of recommendations for the rational design of healthy buildings.
Экология зданий. Анализ и методы проектирования зданий
Возяков И.А, Коммунальное унитарное предприятие «Управление капитального строительства Мингориспол-кома», Республика Беларусь
Ключевые слова: «здоровое здание», проектирование, качество воздуха, экология, микроклимат, ресурсосбережение.
В настоящем документе основное внимание уделяется методологиям разработки руководства по проектированию, а не подробным рекомендациям, которые могут привести к этому. В публикации рассматриваются вопросы проектирования, связанные с качеством воздуха в помещениях и «устойчивой архитектурой». Однако они, как правило, не были установлены на надежной аналитической
основе. Акцент здесь делается на изучении аналитических методов и источников для разработки рекомендаций по рациональному проектированию здоровых зданий. В статье рассматриваются как внутренние условия, особенно проблемы качества воздуха в помещениях, так и общие экологические проблемы. В ней обсуждается оценка воздействия зданий на окружающую среду в целом. Она также анализирует имеющиеся данные для определения норм важных параметров зданий и анализирует основные исследования воздействия зданий на здоровье жильцов. Анализ, представленный здесь, призван помочь проектировщикам зданий определить приоритеты альтернативных вариантов проектирования, которые минимизируют вредное воздействие на внутреннюю и общую окружающую среду.
A healthy building is one that adversely affects neither the health of its occupants nor the larger environment. Indoor air quality (IAQ) concerns are among many indoor environmental issues that must be addressed to avoid adverse impacts on occupants' health and well-being. Among the other indoor environmental factors that must be considered are the quality of thermal, light, acoustic, privacy, security, and functional suitability. In addition to concerns about indoor environmental quality and its effect on occupants, buildings must not adversely affect the larger environment. The construction, operation, use, and ultimate disposition of a building must have minimal adverse effects on the natural environment or ultimately it will adversely affect people whether indoors or out. Buildings are healthy only if their effects on their occupants and the larger environment are benign.
Very little analysis has been done to form the basis of design of environmentally benign buildings. At best, designers have simply attempted to apply known design solutions to decrease the negative impacts buildings have on the environment. This paper discusses methodological approaches to establishing priorities for environmental problems that can be addressed by building design. In order to study buildings' impacts on their occupants and the larger environment, building ecology has been proposed as an interdisciplinary, systematic approach.
There is a definition of the concept of «Healthy building» and it depends on two components:
1) I Indoor environmental quality refers to all aspects of the indoor environment that affect the health and well-being of occupants. This must include not only air quality but also light, thermal, acoustic, vibration, and other aspects of the indoor environment. With respect to the indoor environment, a healthy building is one that does not adversely affect the occupants. Some authors suggest that it should even enhance the occupants' productivity and sense of well-being to be considered healthy. Thus, it is not only the absence of harmful environmental characteristics
but also the presence of beneficial ones that defines a healthy building. Thus, designers should begin by avoiding harmful elements and attempt to incorporate supportive, beneficial ones.
2) The general environment (as used in this paper) refers to the environment of the entire planet Earth. This is obviously an enormously large and complex subject. Nevertheless, the concept of a healthy building must include concern for the impacts of the building on the total environment. Environmental degradation ultimately limits the healthiness of any building. Some environmental problems, although caused by local or regional pollution or resource consumption, result in impacts with important global implications. These include destruction of the ozone layer, global warming, loss of biodiversity, and destruction of unique habitats. Resource consumption and pollution emission result in important local is impacts such as contamination of surface and groundwater, destruction or consumption of natural resources, photochemical smog, acidification, eutrophication, soil degradation and soil erosion. A healthy building is defined as one that has minimal impacts on the local and global environment. Table 1 shows the criteria for healthy buildings.
Тable 1
Important factors for which «Healthy Building» criteria should be established
Environmental focus Criteria focus
Indoor environmental quality Thermal environmental quality
Indoor air quality
Illumination Illumination
Acoustics
Functional support
Security
Privacy
General environmental quality Mineral resource consumption
Energy consumption
Natural resource consumption
Habitat destruction, Biodiversity loss
Land use
Atmospheric pollution
Water pollution
Soil pollution
Determination of a building's healthfulness must be based on specific criteria that can be evaluated by measurement or by informed, structured judgment. Table 1 contains a list of factors for which such criteria should be established and used in the design of healthy buildings [1].
The impacts of buildings on the quality of the indoor environment and the general environment are determined by numerous factors during design, construction, operation, maintenance, and ultimate disposal of a building. They are also determined by occupant behaviors and activities, sources introduced by cooking, cleaning, personal hygiene, office products, decoration, plants, and numerous other sources. Designers only control the intended construction; builders, users, managers, and others determine many building factors that determine indoor air quality. However, designers can improve the likelihood a building will be healthy with respect to indoor air quality by anticipating the use of the building and providing for it in their designs. Where building use cannot be anticipated, general principles can be applied and flexible designs can provide for various potential uses.
The indoor air factors under the control of the designers are the materials and systems, the ventilation, the environmental control scheme, the layout, etc. All of these significantly affect indoor air quality and other environmental factors. However, any dysfunction in the indoor environment potentially affects occupant health and well-being. When buildings fail to do what they are intended to do, indoor environmental pollution in the form of indoor air pollution, noise, glare, etc. cause occupant discomfort, health problems, and poor performance. Space does not permit discussion of the whole range of design issues in the indoor environment; this paper focuses on indoor air quality. A healthy building is one that works well to provide for the intended users and activities.
The most important building design and material selection indoor air quality considerations have been discussed extensively. A rational process for building design decisions on building-related environmental factors most critical to occupant health and comfort should be based on the following:
1. The most significant health and comfort outcomes (based on frequency and gravity);
2. The plausible causal environmental factors; and,
3. The building design elements that control those factors.
A scientific basis for building design and material selection to achieve good indoor air quality is still available only to those willing to draw inferences from their studies. Scientific studies of indoor air quality and occupant health and comfort usually identify only associations of risk factors but do not demonstrate causality. Logical analysis and examination of the dominant evidence can be used
to hypothesize certain root or primary risk factors. Designers implicitly hypothesize causality in determining what factors are important and how to address them. Designers can best target their indoor air quality control efforts based on analysis of identified risk factors and logical plausibility. The process described here will help design efforts have maximum impact on primary or root building factors contributing to the prevalence of sick building syndrome and building-related illness.
There are three main approaches to identifying the most important factors and establishing design criteria. They are shown in table 2.
Тable 2
Three approaches to identify important indoor air quality design factors
Approach Method/Comment
Characterize factors important to indoor air Review and analyze major building epidemiology studies and meta-studies of their results
Establish norms for design Review and analyze major building indoor environmental factors characterization studies
Test hypotheses using intervention studies IStudy effect of changing hypothesized critical variable on outcome of interest
Using the first approach - characterization of factors believed important to indoor air quality - if elevated volatile organic compounds, are often associated with elevated SBS symptoms, then volatile organic compounds can be controlled by design. The first approach involves reviewing studies of occupant responses that determine their associations with the different environmental conditions. These may be building investigations, studies, or surveys. Then the second method - establishing norms - can be done for important volatile organic compounds and their relevant concentrations by reviewing data from comprehensive surveys that characterize volatile organic compounds most commonly found in buildings. The third approach (not discussed here) uses intervention studies to test hypotheses developed using the first two approaches.
The second and third methods are relevant to determining control strategies -evaluation of the common volatile organic compound control strategies including source control and ventilation. Normative values can be based on what has been observed in studies and surveys. The norms can be used as a basis for design or for evaluation of existing conditions. The methods and outputs of the first two approaches are very different, but both are valuable sources of data that can be used to assist designers determine values and criteria for their work. The results of
the use of the first two approaches is discussed below.
Priority attention in the design is given to indoor air quality. The elimination of those construction factors that are primary or root factors among the risk factors is expected to have the greatest impact on the prevalence of symptoms of sick building syndrome. «Root factors» are primary or basic; they can be managed directly, and their results can be secondary or indirect risk factors. Elevated temperature is a major risk factor because it increases the rate of growth of microorganisms and emissions of volatile organic compounds from materials. It also affects residents' perception of air quality. Low relative humidity is a secondary factor compared to elevated temperature and air conditioning. Concentrations of volatile organic compounds (including formaldehyde) are the result of one or more factors, including improper material selection, insufficient ventilation (low ventilation rate or insufficient operation) and elevated temperature. But the elevated temperature can also be the result of other risk factors, such as insufficient ventilation, if the outdoor air temperature is lower than the indoor air temperature.
In addition to risk factors, some factors logically represent important risks. These are the presence of carcinogens or other genotoxic substances, strong or harmful odors, irritants, infectious agents or allergens; extreme temperature or humidity; as well as sources of microorganisms and their amplification and spread. The «reasonable warning» design philosophy dictates that designers apply practical controls that can reduce or eliminate these prior risk factors. The extent of such control efforts will be determined by the judgment of the designer and the client, as well as by regulatory authorities.
Since the etiology of many (if not most) health and comfort problems associated with indoor air is «multifactorial», it is necessary to understand the links between contributing factors. Designers should evaluate these connections, analyze their design implications, and determine their importance for building design and material selection. Analysis of the links between contributing factors can direct projects to consider primary factors rather than their secondary outcomes. The speed of outdoor ventilation, temperature, moisture penetration and strong sources of pollution are the main factors. Increased concentrations of pollutants in the air are the result of one or more of the above main factors [2].
For example, the penetration of moisture into the external walls of a building does not in itself cause health or comfort problems. But the penetration of moisture leads to the growth of mold and, most likely, to an increase in the level of volatile organic compounds in the air, including volatile organic compounds of microorganisms. Designers can specify materials that are resistant to mold (for example, mineral-based products such as stone or brick), or use materials treated with fungicides, but the main problem is the penetration of moisture. The high
activity of water on the surfaces of materials supports the growth of fungi and competes with volatile organic compounds for adsorption sites. Preventing or controlling the penetration of moisture will allow you to control the growth of fungi, reduce the concentration of volatile organic compounds in the air, reduce the relative humidity in the room and extend the service life of building materials and contents. Many problems with comfort and health, as well as expensive restoration measures, can be avoided by directly controlling the penetration of moisture.
Some key factors will have both a direct and indirect impact on the environment of the building and residents. Many of these key factors appear more frequently in studies of associations between residents' symptoms and environmental factors. The key primary factor is the high temperature of the air in the room. Residents feel less comfortable at temperatures close to the upper limit of the thermal comfort zone, and they are more likely to perceive the indoor air as stuffy or stale. In addition, an increase in temperature will lead to an increase in emissions of volatile organic compounds from building materials, furniture and other surfaces due to increased vapor pressure. This will increase the impact on the inhabitants of volatile organic compounds, as well as increase the growth of microorganisms and the impact on the inhabitants of bioaerosols and volatile organic compounds of microorganisms.
Ultimately, the designer and the building owner or occupant determine which preventive or mitigating measures should be applied in a newly designed or renovated building; their decisions are based not only on the perceived importance of measures to reduce the risks of health and comfort problems, but also on the feasibility, practicality and cost of implementing measures. In most cases, compromises are made to achieve the desired result. For example, to reduce the concentration of a pollutant released from a particular material, a decision may be made to 1) choose low-emission products, 2) prepare or process the product before installation in a building, or 3) ventilate the building after installation before settling in.
Avoiding the adverse effects of a building on the environment as a whole may be more difficult than avoiding the adverse effects on residents. The purpose of buildings is to protect people and their property from the dangers and unfriendly forces of the environment. But for this it is necessary to change the natural environment. Resources must be extracted and transformed to create and operate buildings. Water, earth, living organisms and mineral resources are used. Pollutants are released into the air, land and water, waste is generated, which must be disposed of if they are not reused or recycled.
The major impacts of a building on the general environment are related to the materials and energy used for building construction, maintenance, and operation.
Approximately 20% to 40% of all such resource consumption is related to buildings. The impacts occur during the entire life cycle of the building as well as during the production of the building materials and products used to construct it. Life cycle analysis methodologies are now being applied to evaluate the environmental impacts of buildings and advise designers regarding appropriate choices. These efforts are only now beginning, and much research and data gathering is necessary to fully evaluate building design decisions [3].
A recent trend toward increased concern about the impacts of buildings on the larger environment has led many building design professionals to design so-called «sustainable architecture» or «green buildings». Their efforts are intended to reduce harmful environmental impacts of buildings. "Sustainable design" is usually defined as avoidance of environmental damage that will decrease the livability of the planet for future human generations. Some suggest also minimizing impacts on other living species. These are quite strongly interdependent, so treating them independently is dangerous. Regardless of which view one adopts, sustainable design remains an abstract goal not currently achieved by efforts in industrialized societies. The best that is being done now is to reduce the magnitude of the harmful environmental impacts imposed by most building activities.
Efforts to provide advice to designers abound. Among the most prominent are the BSRIA, BEPAC, and AIA Environmental Resource Guide (ERG). Each ofthese has been published - the AIA's ERG being the most elaborate weighing in at more than 5 kg. But each of these publications and a rapidly growing number of others providing advice on «sustainable design» generally fail to provide any direction for prioritizing the various environmentally-conscious actions they recommend. Inevitably, designers must prioritize various design alternatives and recommend favored ones to their clients from among them. Design is always a matter of tradeoffs, No building is likely to be completely harmless to the environment. The real question is how to boost efficiency in terms of energy and other resource use and in terms of reducing pollution while learning to build more sustainably.
The Life Cycle Analysis process widely cited for building design has evolved from Life Cycle Analysis methods used for consumer products. It has been codified by the Society for Environmental Toxicology and Chemistry (SETAC). It has also formed the basis for industrial ecology used to improve industrial processes and plant operations. The traditional use of Life Cycle Analysis has been to evaluate consumer products. However, these evaluations have focused on inventory and impacts related to the production and disposal of consumer goods while largely ignoring the product's use phase. Building designers, operators and users must emphasize the use phase when they design, so a more meaningful «modified Life Cycle Analysis process» includes the use phase. A building design-oriented
adaptation of the Life Cycle Analysis process is shown diagrammatically below.
Inventory ^ Impact ^ Valuation/Ranking ^ Design ^ Implementation ^ Feedback
Determining What's Important to Guide Design To guide design to reduce buildings' environmental impacts, it is important to prioritize efforts according to the most critical environmental problems. For example, is global warming a more important problem than ozone depletion or biodiversity loss? Should design efforts to minimize one of these or other problems dominant or be submerged relative to other design alternatives? The problem of deciding what to do during design is unmanageable due to the large number and the inter-relatedness of the various environmental concerns. The necessary prioritization can be done by examining the total impact of buildings on the environment and by ranking the most important environmental problems. This will allow a hierarchy of design features related to environmental protection.
To assess buildings' contributions to Life Cycle Analysis inventory flows and environmental impacts, estimates of building-related contributions were prepared. Building-related raw materials uses average about 40% raw material consumption. Building operational energy use is >35% with an additional 5% or more energy use embodied in building materials. Water use, including industrial and power plant operations attributable to building construction and operation, is ca. 20%. Building-related atmospheric emissions of CO2 for building-related energy use and for producing building-related materials are >30% totals. Between 25% and 35% of solid waste produced is building-related - either direct (e.g., from construction, demolition) or indirect (e.g., mining resources for building materials and products).
These data indicate that building-related contributions to total inventory flows and environmental impacts normally assessed in Life Cycle Analysis are large and, therefore, important. The detailed analyses for these estimates are being used to scope ongoing modeling and to prioritize data gathering efforts aimed at developing guidance for building designers, product manufacturers, and others trying to create «sustainable» buildings or «green» building products.
By studying the impact of buildings on the environment, it is possible to identify those that cause the greatest concern. By assessing inventories for priority impacts of concern, activities for the design, production, construction and operation of buildings can be focused on those that are most likely to lead to the creation of buildings that are the least environmentally harmful endpoints of concern. Currently, work is underway to improve the reliability of cadastral estimates. Work is also being carried out to identify a network or chain of impacts in order to classify the endpoints of concern and identify the impact vectors of the inventory
that are of greatest importance.
A simple illustration of the application of criteria that might be developed for healthy material selection considering the indoor air quality, indoor environment, and the general environment is shown in Table 3. The importance of each factor for each environment is indicated by the number of marks in the matrix. This exercise shows that there is considerable overlap among the criteria for different environmental compartments.
Table 3
Sample Matrix of Criteria for Healthy Materials Selection
Material Selcetion Criteria Indoor air quality Indoor environment General environmental
Resource conservation X XXX
Durability XX X XXX
Low emissions/pollution production XXX
Low emissions/pollution finished XXX XX
Maintenance chemical requirements XXX X XX
Replacement frequency XX X XXX
Hard surface (IAQ vs. acoustics) XX XXX
Smooth surface XXX XX X
Energy consumption X XX XXX
Following is preliminary design guidance that attempts to integrate both indoor and general environmental considerations.
Selecting building materials and products that are extremely durable and are expected to perform well over a long service life will generally result in a better environmental choice than one that needs to be replaced twice or even ten times in the same time period [4]. This is evident from an approximately tenfold increase in the relative additional extraction/consumption of resources, production, transportation, installation and disposal. The roof used in many European buildings can last from one hundred to three hundred years, while our standard roofs last from ten to thirty years. Long-lived products are an inherently preferred solution for resource conservation and environmental protection.
Re-using materials and products that have reached the end of their useful lives is the next most effective way to avoid withdrawal of additional resources and creation of environmental pollution associated with the extraction, transport,
processing, manufacturing. and installation. A longer-lasting material is inherently more desirable.
Durable materials tend to have low emissions. Therefore, the tend to be better for indoor air quality than less durable ones. They may also require less frequent application of maintenance and surface renewal chemicals and use of less harmful chemicals. There is a sort of multiplier effect from the use of durable materials.
Designs that assume frequent changes in interior partitions should provide for re-mounting durable ones rather than demolition/disposal and new construction.
Controlling pollution at the source is generally four times as cost effective as removing pollution from air, water, or soil. This applies both to indoor air as well as ambient air. It also applies to both surface and groundwater water. It is widely accepted that the most effective strategies for indoor air quality involve reducing indoor air pollutant sources and their source strengths or toxicities by one of the following measures: elimination, reduction, substitution, or source isolation. Important considerations for material selection and indoor environmental quality include functional requirements, surface characteristics, total mass, chemical composition and emissions, durability - longevity, and cleaning, maintenance and renovation requirements. Selecting low-emitting materials, especially for those products that will be present in large quantities by mass or exposed surface area, is also important to reduce emissions to the general environment. Typically, low-emitting products will have resulted from production processes involving lower exposures of the manufacturing workers [5].
Design for effective moisture protection is important to prevent intrusion of water from outdoors through cracks, openings, or semi-permeable membranes and eliminate potential for standing water or condensate inside the building from chilled water systems. This will prevent the growth of microorganisms. This will also prolong the life of the building and its components resulting in resource conservation.
The first step toward reducing energy consumption and conservation. This includes effective building envelope insulation, tightly-sealed openings, and control of air movement and thermal transport mechanisms between the buildings and the outside and, in some cases between spaces within the building. This does not mean minimal ventilation; it means reducing the requirements for conditioning ventilation air by avoiding unintentional thermal losses. Energy conservation will produce more comfortable indoor environments. Energy conservation is extremely important in reducing potential emissions of greenhouse gases at power plants, and acid-forming gases that cause acid deposition. This will also reduce the need for refrigeration involving ozone-depleting compounds.
Where energy-consuming devices are required (such as fans, pumps, motors,
appliances, etc.) it is essential to select efficient appliances. The rate between the best and worst in a class of products may easily be 2-to-1 or even 3-to-1, so it does make a great deal of difference which product is selected.
Also, ensure adequate ventilation to control pollutants that reach the indoor air by reducing and removing them through dilution, exhaust (local, general), filtration, and air cleaning. Occupant controlled ventilation can produce energy savings while reducing occupant stress and building sickness symptoms.
The human body and mind integrate all factors of the physical, chemical, biological and psychosocial environment. The full integration of environmental considerations in the design will include not only indoor air quality, but also thermal comfort, lighting, acoustics and spatial relationships. Such constructions will be inherently healthier. A building that meets the needs of its users (residents, operators and others) will last longer and will not require demolition, replacement or other resource-intensive and polluting actions. The more satisfied the users of the building are, the longer the building will remain in operation, which will avoid the need for additional construction.
Building design and indoor environmental quality issues must be considered throughout the process of planning, design, construction, use, and disposal/reuse/recycling buildings. The major design phases include site selection, project feasibility, budgeting, building configuration, building envelope, environmental control scheme, energy considerations, and environmental impact analysis.
This paper has emphasized a «building ecology» view of buildings as dynamic, interdependent systems. This view argues for planning during the design phase for varying cycles of building performance and use or requirements during the building's lifetime. The more specific the analysis, the more relevant its application to any given building design. Generic analyses are helpful but suffer from the potential to miss important characteristics of a particular situation.
Examining sample decisions, it becomes apparent that in many instances, the design alternative best for indoor environmental quality is also best for general environmental quality. For example, durable materials will be less likely to emit contaminants into the indoor air, will require lower quantities and less toxic chemicals for the maintenance and refurbishing, and, by definition, will be longer lasting. Service life is an extremely important determinant of overall impact on the general environment since each replacement cycle requires the use of additional resources with the concomitant pollutant emissions.
Designers must be aware of the impacts of the building on the larger environment. These will include impacts on biodiversity, global warming, ozone depletion, on the soil, air, and water, on resource depletion, on waste generation, and on energy consumption. Some of these will ultimately, although perhaps imperceptibly,
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«Экономика строительства» № 6 (72) /2021
affect the building itself and its users. Therefore, each building must be planned and designed as though it were being replicated a million times over so that we take seriously the consequences of its impacts on the global environment and, in a very real sense, its own environment.
References
1. AIA, 2020. «Environmental Resource Guide». Washington, D.C.: American Institute of Architects.
2. Aizlewood, C. and R. Walker, and D. Dickson, 2014. The European audit project to optimize indoor air quality and energy consumption in office buildings; national preliminary results: UK. Poster presentation at Healthy Buildings '14, Budapest.
3. ASHRAE, 2020. Standard 55-2020, Thermal comfort for human occupancy. American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc., Atlanta.
4. BEPAC, 2012. Building Environmental Performance Assessment Criteria; Version 1, Office Buildings, British Columbia. Vancouver: University of British Columbia School of Architecture.
5. BSRIA, 2012. Environmental Code of Practice for Buildings and Their Services. Bracknell, Berkshire, UK: The Building Services Research and Information Association. 130 pp.
Автор
Возяков Игорь Анатольевич, ведущий инженер технического надзора, Коммунальное унитарное предприятие «Управление капитального строительства Мингорисполкома», Республика Беларусь (Минск, ул.Советская, 17); тел. +375 44 5395378; e-mail: 180185@tut.by
