High-rise buildings are being constructed along slender roads and even on small plots in neighbourhoods where most other buildings are one to three storeys high. They do not abide by any building code. The widespread practice is to exploit the entire land to erect the building without leaving tolerable space between the buildings which blocks out natural light and fresh air. Multistoried buildings being built by real estate companies do not always follow the construction regulations set by the urban development authority of Bangladesh.
A high-rise building is defined by its height differently in various jurisdictions. It is used as a residential, office building, or other functions including hotel, retail or with multiple purposes combined. The materials used for the structural system of high-rise buildings are reinforced concrete and steel.High-rise structures pose particular design challenges for structural and geo-technical engineers, particularly if situated in an active region or if the underlying soils have geo-technical risk factors such as high compressibility. They also pose serious challenges to firefighters during emergencies in high-rise structures. New and old building design, building systems like the building standpipe system, HVAC systems (heating, ventilation and air conditioning), fire sprinkler system and other things like stairwell and elevator evacuations pose significant problems. Apartment buildings have technical and economic advantages in areas of high population density and have become a distinctive feature of housing accommodation in virtually all densely populated urban areas around the world.
In developing countries, urbanisation is not only an indicator of development, but ironically an outcome of abject poverty and joblessness in rural and marginal urban centers. Therefore, only urbanisation will not serve the objectives of reducing or eliminating urban problems like slums and squatter settlements, congestion in roads, supply failure in housing, water, transport and infrastructures, depletion of parks and open spaces. Planning must be done to distribute the demand in the surrounding urban centers and also for providing required facilities there. Today here in Bangladesh, migration is the prime source of urban population growth particularly in the major cities.
At this moment high-rise buildings dominate many regions of Dhaka city. These buildings have enormous dissident reservoirs to hold water. The pressure of water in the distribution pipes of WASA is not enough to fill these huge reservoirs - water is taken through these pipes by illegally connecting water pumps straight on WASA lines. As a result, other houses in the neighbourhood undergo water shortage. Dhaka city is served by a sewerage system, which is not able to accommodate huge loads of sewage at specific points. The high-rise apartment buildings are creating extra load of sewage at specific points at specific times of the day. This may debilitate the whole system. Where there is no sewerage line, huge septic tanks need to be erected to collect the sewage. If constructed in dangerous revitalise areas, this may contaminate the groundwater, pollute the land and surface water ecology.
In the city, electricity and water supply is not ensured, quality is a far cry. The poor are the worst sufferers and they are further exposed to diseases due to poor sanitation. Urban authority cannot replace the unhygienic latrines, if any, in their shanties. Open dustbins on roadsides overflow with garbage. Roads and drains go under knee-deep water not only in monsoon but also after a sudden shower.
Waste collection and disposal may be another threat next to environmental security arising from high density housing if these are not managed properly. Many of the high-rise buildings, especially those housing commercial units, do not have proper parking space and creates sound pollution. Car parking on busy roads disrupt the flow of traffic and cause traffic jams, burning more fuel and polluting the air.
On the one hand we have to increase employment, facilities (health, education and recreation), utilities (gas, electricity, water, etc), infrastructure (housing, transport), etc. available to the people in the villages or at least to the citizens of upazila and district towns. On the other hand we have to give up the practice of haphazard and rampant development of alluring urban areas to reduce pressure on urbanisation in the cities. The housing shortage is so acute that one third of the city’s population lives in slums. Parks and open spaces are gradually disappearing. The influx of migrants from rural areas and small towns continue. The city authorities can neither respond to the problems nor coordinate their work.Every year, 8th November is celebrated as world urbanism or world town planning day. This special day recognises and promotes the role of planning in creating livable communities. World Urbanism Day presents an excellent opportunity to look at planning from a global perspective, an event which appeals to the conscience of citizens and public authorities in order to draw attention to the environmental impact resulting from the development of cities.
In our country, there are a lot of real estate companies working for new settlements. They should consider freedom from noise, fresh air and day light for new construction. Government can take home-grown development strategies for eco-friendly construction. Environmental security is an important element of sustainable development. If we plan for new building both for present and future generation, we have to value the environment. As Bangladesh is becoming middle income country by 2021, we should ensure environmental security in new urban development.
Regarding this world urbanism day, we have to commit to diminish environmental pollution, address unplanned construction of high-rise buildings all over the country, abide building codes, ensure proper solid waste disposal system, etc. It is imperative to have proper urban and regional planning for sustainable climate resilient cities and communities in Bangladesh.
Shishir Reza, an environment analyst