Being an integral component of the urban fabric, the construction and operation of buildings have a huge active and passive impact on the environment. Energizing the cities with sustainable building design assures that the buildings will not only ingest resources like energy and materials but also produce wastes and potentially threatening atmospheric emissions. Therefore, as the urban fabric being etched with the growth of spawning built forms, particularly referring to the context of Dhaka, where it lacks any control over the urban grain but growing in its own way, defying the truth of scarcity in land, energy and continuingly deteriorating environment, designers should consider it as a social challenge to produce a building with a maximum sustainability to minimize the impact on the environment. The upcoming building, being under process at the pen-tip of the designers as a whole, thus should embrace the above truth. On the other hand, the conceived building should also incorporate accessible, flexible, secure, safe, healthy and productive factors.
The objectives behind conceiving such sustainable building are to minimize the degradation of the environment by avoiding the depletion of energy, water and raw materials without hampering the criteria for creating a building that would be productive, comfortable and safe. This is a new challenge: an integrated and synergic approach should be made beforehand rather than conceding building disciplines at a later stage when this would be too late.
While the definition of what constitutes sustainable building designs is constantly changing, there are six fundamental principles that almost everyone agrees on:
• Optimization of Site Potential
Creating sustainable buildings starts with proper site selection, including consideration of neighbouring existing buildings. The location, orientation, and landscaping of a building affect local ecosystems, transportation methods and energy use and therefore these components of the ecosystem should not be considered as afterthoughts.
• Optimizing Energy Use
With global supply of fossil fuel dwindling, concerns for energy security increasing, and the impact of greenhouse gases on world climate rising, it is essential to find ways to reduce load, increase efficiency and utilize renewable energy resources in buildings.
• Protecting and Conserving Water
Being overburdened with an expanding population, Dhaka faces the scarcity of fresh water that could be worsening in the near future. Therefore, buildings should have a sustainable approach to control, or treat site-runoff, use water efficiently and reuse or recycle water for on-site use when feasible.
• Using Environmentally Preferable Products
A sustainable building should be constructed of materials that minimize life-cycle environmental impacts such as global warming, resource depletion, and human toxicity. As such, they contribute to improved worker safety and health, reduced liabilities, reduced disposal costs and achievement of environmental goals.
• Enhancing Indoor Environmental Quality
The indoor environmental quality of a building has a significant impact on occupants' health, comfort and productivity. Among other attributes, a sustainable building should maximize day lighting; have appropriate ventilation and moisture control; and avoid the use of materials with high-Volatile Organic Compound emissions. Additional consideration shall be given to ventilation and filtration to mitigate chemical, biological and radiological attack.
• Optimizing Operational and Maintenance Practices
Incorporating operating and maintenance considerations in the design of a facility will greatly contribute to improved working environments, higher productivity and reduced energy and resource costs. Emphasis shall be placed on specifying simplified and low maintenance materials and systems during the designing of the building to ensure a cost-effective and a low life-cycle cost system for the proposed building.
The Emerging Culture of Office Building
"The office building is one of the great icons of the twentieth century. Office towers dominate the skylines of cities in every continent… [As] the most visible index of economic activity, of social, technological, and financial progress, they have come to symbolize much of what this century has been about."
--- Francis Duffy, consultant and author
The essence of the above statement entails the truth that in today's world the most tangible elements in urban fabric are being depicted by office buildings. The changing employment pattern, which was only 5% at the beginning of the 20th century, turned into 50 percent in the developed world. The wave of such changing patterns finally rippled down to some extent to even under-developed countries like Bangladesh. Being one of the most populous countries, though economically weak, Dhaka as the capital city could attract such an influx of employment by investors. The recent trend in corporate culture in Bangladesh has turned Dhaka into the most concentrated hub for such development. As a result, for the last decade, Dhaka has been highlighting some apparently magnificent office buildings. But in terms of their sustainability, there remains a big question as most of them stay far apart from a consideration of facts related to sustainability.
However an interesting phenomenon is that the life-cycle cost distribution for a typical office is about 3 to 4 percent for the facility, 4 percent for operations, 1 percent for furniture, and 90 to 91 percent for salaries. As such, if the office structure can leverage the 3 to 4 percent expenditure on facilities to improve the productivity of the workplace, it can have a very dramatic effect on personnel contributions, representing the 90 to 91 percent of the service organization's costs.
To accomplish this goal, the buildings must benefit from an integrated design approach that focuses on meeting a list of objectives. Through integrated designs, a new generation of high-performance office buildings is beginning to emerge that offers owners and users increased worker satisfaction and productivity, improved health, greater flexibility and enhanced energy and environmental performance. Typically, these projects apply life-cycle analyses in optimizing initial investments in architectural designs, systems selection and building construction.
The building attributes to be considered for a sustainable office building are flexibility and a technologically-advanced working environment that include safe, healthy, comfortable, durable, aesthetically-pleasing and accessible characteristics. Therefore, the proposed office must be able to accommodate specific space and equipment needs of the tenant. Special attention shall be given to the selection of interior finishing and art installations, particularly in entry spaces, conference rooms and other areas with public access like lobby, café, restroom, child care centres, gym, informal common space, multi-purpose recreation and social gathering space.
The proposed building shall be targeted to be a high-performance office and shall be evaluated through using life-cycle economic and material evaluation models. Maybe in some cases, to achieve a high-efficiency and sustainable building, the owner needs to have a mindset of investing more initially to save on long-term operations and maintenance.
The building design will integrate the requirements of the intended tenants. This includes their desired image, degree of public access, operating hours, growth demands, security issues and vulnerability assessment results, organization and group sizes, growth potential, long-term consistency of needs, group assembly requirements, electronic equipment and technology requirements, acoustic requirements, special floor loading and filing/storage requirements, special utility services, any material handling or operational process flows, special health hazards, use of vehicles and types of vehicles used, and economic objectives.
As a major segment of the costs to run an office goes into paying the salaries of employees, therefore the health, safety and comfort of employees will be considered with serious concern. To be effectively productive, the office environment along with the facilities shall be considered in the proposed building. To accomplish a safe and comfortable office atmosphere, the following things shall be given importance:
• Utilizing strategies such as increased fresh air ventilation rates, the specification of non-toxic and low-polluting materials and systems, and indoor air quality monitoring.
•Providing individualized climate control that permits users to set their own, localized temperature, ventilation rate and air movement preferences through VAV units.
•Though difficult to quantify, it is widely accepted that worker satisfaction and performance is increased when office workers are provided with a stimulating and dynamic working environment. Access to windows and views, opportunities for interaction and control of one's immediate environment are some of the factors that contribute to improved workplace satisfaction.
•The acoustics of the office shall be designed and integrated with the other architectural systems and furnishings of the office. Special consideration shall be given to noise control in open office settings, with absorptive finish materials, masking white noise and sufficient separation of individual occupants.
Technology has become an essential tool for business, industry and education. Given that technology is driving a variety of changes in the organizational and architectural forms of office buildings, the following issues shall be considered when incorporating technology in the proposed office:
•Planning new office buildings to have a distributed, robust and flexible IT infrastructure, which would allow technological access in virtually all spaces.
•During the planning stage, identifying all necessary technological systems (e.g., voice/cable/data systems such as audio/visual systems, speaker systems, Internet access, and Local Area Networks [LAN] / Wide-Area Networks [WAN] / Wireless Fidelity [WI-FI]), and providing adequate equipment rooms and conduit runs for them.
•Considering and accommodating wireless technologies, as appropriate.
Energy Efficiency—Depending on the office's size, local climate, use profile and utility rates, strategies for minimizing energy consumption shall involve reducing the load by integrating the building with the site, optimizing the building envelope decreasing infiltration, increasing insulation etc; precisely sizing the heating, ventilating and air-conditioning systems; and installing high-efficiency equipment, lighting and appliances. Consideration shall be given to the application of renewable energy systems such as building-integrated photovoltaic systems that generate building electricity, solar thermal systems that produce hot water for domestic hot water or space conditioning, or geothermal heat pump systems that draw on the thermal capacitance of the earth to improve HVAC system performance.
Additional consideration shall be given to the application of other distributed energy sources, including micro turbines, fuel cells, etc., that provide reliability (emergency and mission critical power) and grid-independence, and reduce reliance on fossil fuel grid power.
In today's mechanized high-tech world, the office is continuingly changing its pattern to meet the demand of technological innovations and corporate business culture. Changing trends are giving birth to a demand for a workplace ambience that is suitable in terms of flexibility to anticipate the rapidly changing scenario. In recent developments, global office ambience has been made the product of designers to accommodate such 'flexible-generation' workplace environment within office buildings that support the sustaining new technological changes.
The changing nature of work means greater mobility for workers, a multiplicity of work spaces within and external to buildings, greater use of geographically dispersed groups, increased dependence on social networks—and greater pressure to provide for all of these needs in a leaner and more agile way. Workplaces have responded with many new options, including more teaming and informal interaction spaces, more support for virtual individual and group work, more attention to integrating learning into everyday work experience, greater flexibility in work locations, and more focus on fitting the workplace to the work rather than the other way round. Many workplaces are also incorporating spaces that encourage a relaxed engagement with colleagues to reduce stress and promote a sense of community.
Increasingly, compatible and packaged building components are available on the global market and meet these goals. Several vendors sell systems comprising raised floors, plug and play wire management components, and demountable wall systems as a single package.
Open controls protocols such as LonTalk and BACNet, which allow communication between different types of building systems (HVAC, lighting, security, fire alarm, and power), are being adapted to an increasing number of products. This will enable a wider range of cost-effective possibilities for user control over an open protocol.
In the process of designing proposed buildings, emphasis should be placed on improving Indoor Environmental Quality (IEQ). In many cases it is being forgotten that to retrieve the best from employees it is a must to put them in a healthy and comfortable working environment.
During the facility design and development process, a comprehensive, integrated perspective shall be made that would seek to facilitate quality IEQ through good design, construction and operating and maintenance practices; valuating aesthetic decisions, such as the importance of views and the integration of natural and man-made elements; providing thermal comfort with a maximum degree of personal control over temperature and airflow; supplying adequate levels of ventilation and outside air to ensure indoor air quality; preventing airborne bacteria, mold, and other fungi through Heating, Ventilating, Air-Conditioning (HVAC) system designs that are effective in controlling indoor humidity and moisture; and creating a high performance luminous environment through the careful integration of natural and artificial light sources; and providing quality water.
Psycho-social Value of Space
"What would a building space look and feel like if it were designed to promote psychological and social well-being? How would it affect the senses, the emotions, and the mind? How would it affect behavioral patterns and sense of community?
For an insight, it is useful to look not at buildings, but at zoos. Zoo designs have gone through a radical transformation in the past several decades. Cages have been replaced by natural habitats and geographic clustering of animals. In some places, the animals are free-ranging and visitors are enclosed in buses or trains moving through the habitat. Animals now exist in mixed species exhibits, more like their natural landscape. And, as in nature, animals have much greater control over their behavior. They can be on view if they want, or go out of sight. They forage, play, rest, mate and act like normal animals."
Judith Heerwagen, J.H. Heerwagen& Associates, Inc.
There is something that brought about a change in philosophy in a designing of zoos. It had been revealed from the study on animals caged in the zoos that the often the caged animals show neurotic behavior instead of being natural. The above statement on the animal behavior is nothing different from our everyday lifestyle in the office building. The current global trend thus took the lesson from zoo life and is intended to employ thoughts on the changing patterns in our lifestyle. Can't we apply these lessons from zoos to our building design? The answer is obviously "yes".
Therefore, during the process of the proposed building the following factors shall be considered to achieve a workplace with a high physiological value:
• Looking beyond survival to well-being
• Building on "primeval preferences" and connections to nature
• Designing for the senses as well as the body.
Window views that provide contact with outdoor nature reduce stress and improve psychological functioning. In the absence of windows, workers frequently decorate their workstations with nature décor.
Daylight and Sunlight
It is not surprising that people working in an office prefer high level of natural daylight. Recent study reveals that as much as 80% of workers prefer working in the day light with compare to 55% occupying more interior workplaces. Therefore, during the process of design for the proposed building most priority shall be given to achieving such preferences for day light. If not possible in all cases to provide direct daylight, there shall be effort to introduce a scope of visualizing the daylight from interior glazing, even if the workers do not have daylight in their immediate space. It is believed that merely seeing the daylight somewhere in the office environment shall also have a positive impact on the working environment for those particular workers.
Although daylight design generally tries to reduce or eliminate sunlight in buildings, a modest level of sunlight may be beneficial to health and well-being. Daylight and indoor sun patches create visual stimulation and shall also improve psychological functioning of building occupants, as long as sun is not excessive or an impediment to work.
Design for the Senses
Given our similarity to nature, are there general properties of living things that might serve as valuable design guides? Although there is less research evidence on this topic, it is reasonable to look for general characteristics of living organisms and life-like processes that could form the basis for the design of proposed whole buildings, spaces, layouts, artifacts, and landscapes.
Characteristics of living organisms and life-like processes include movement, organized complexity, fractal patterning, organic shapes, emotions and shapes and multi-sensory.
Buildings affect our psyche as well as our bodies. They can be inspiring and supportive of daily activities, or they can deplete the spirits and undermine the best intentions of the designer. It is not by chance that such results occur. Therefore, effort shall be made for the proposed building for a positively experienced, psychologically healthy building that would host features that distinguish it from less enjoyable buildings. Thus the proposed building shall be designed around basic human needs to embody high psychosocial value, ancient preferences, and connections to the patterns of nature and the mind.
Introducing daylight to interior spaces in the general sense does not require any special attention but the art of designing, the intrusion of the daylight within the indoor space without the side-effects is the tricky part of the design. Therefore, during the design process the importance of daylight shall be given its due priority with regard to the side-effects like direct heat gain and loss, glare control and variation in daylight availability minimization. Filtering the daylight and bringing it in the workplace shall be the utmost important factor during the analysis of its source while the attempt shall be made to avoid high-contrast in the workspaces.
It is understood that daylight has the potential to significantly improve life-cycle cost, increase user productivity, reduce emissions and reduce operating costs. It is important that the daylight design process involve the integration of many disciplines --- architectural, mechanical, electrical and lighting. These design team members shall be brought into the process early to ensure that daylight concepts and ideas are carried throughout the project.
The aim of an efficient daylight design is not only to provide illumination levels sufficient for good visual performance, but also to maintain a comfortable and pleasing atmosphere.
The author is principal architect & managing director of Vistaara Architects (Pvt.) Ltd.