Additional Urban Planning Strategies and Techniques to Achieve Energy-Efficient, Smart and Sustainable Buildings

To realize sustainable and energy-efficient buildings, Fig. 6 summarizes additional considerations to be kept in mind during urban planning.

According to Fig. 6, the type, size and facing direction of windows are important considerations to reduce energy consumption in buildings. Large windows, ideally facing north with a north-south cross ventilation scheme in the southern hemisphere and facing south in the northern hemisphere, will ensure that abundant natural light enters the building to heat the environment naturally during cold months. A north-south cross-ventilated scheme will allow wind to pass through the building and cool down the environment during warmer months. A naturally light environment and clear sight to the outdoors also help improve the morale of occupants.

Water efficiency is the smart use of water resources by using water-savings technologies and ensuring reliable water supplies in commercial and residential buildings. Accompanied by rainwater harvesting and leak detection, efficient water-savings strategies include:

• • installing efficient and reputable plumbing fixtures, pipes and distribution points,
• • using non-potable water where possible,
• • installing sub-meters to ration and distribute water effectively, based on varying demand,
• • implementing rainwater harvesting for non-drinkable water uses,
• • choosing drought-tolerant and slow-growing vegetation (xeriscaping) for rooftop gardens or vertical gardens to decrease ambient temperature and promote cleaner (CO₂ absorbed) air,
• • ensuring proper leak detection mechanisms and implementing regular maintenance of water distribution pipes,

Fig. 6 Additional urban planning strategies and techniques to achieve energy-efficient, smart and sustainable buildings

• installing appropriate irrigation technologies and using non-potable water for

landscape irrigation, and

• installing heat pumps as opposed to traditional warm-water geyser systems and

using in-line water transfer pumps.

Also shown in Fig. 6 is consideration of feasible and environmentally practical implementations of alternative energy sources and consideration for micro-grids. Alternative energy sources include photovoltaic solar cells, wind energy or hydro energy. Capital investments in alternative energy remain large, with long-term maintenance and replacement of energy storage equipment adding to the overall cost of such an endeavor. Micro-grids are local energy grids independent from traditional power grids, consisting of energy-generation facilities, demand management and energy storage capabilities. Micro-grids aim to lower the demand for traditional transmission and distribution systems and ensure locally generated and reliable energy supply in urban (and rural) settings and therefore lowering overall GHG emissions. Since a micro-grid operates independently from utility grids and is smaller in terms of physical size, a larger number of these micro-grids can be spatially distributed in an urban setting, enabling integrated renewable alternative energy sources at each micro-grid to minimize the carbon footprint within cities. Sustainability and reducing dependence on power utility grids, as well as long-term cost savings and reduced environmental impact, are among the advantages of using alternative energy sources. Urban developments are increasingly using micro-grids because of these advantages and to ensure long-term sustainability.

Installations of smart car parks and planning of naturally ventilated ones can also lead to significant energy savings for buildings and factories, since large numbers of the workforce commute to and from these areas. High-efficiency, variable speed extractor fans with carbon monoxide sensors can reduce the toxicity typically experienced in closed spaces with high movement of cars and other vehicles. These installations allow for ductless car parks, leading to savings on materials and space, as well as savings on operational cost due to the lower power consumption of axial fans and elimination of ductwork.

Jonsson (2004) studied the influence of vegetation on the urban climate in the subtropical and rapidly expanding city of Gaborone, Botswana. The study found an apparent opposit effect of rural and urban vegetation, where the former was hindering the temperature from falling and the latter was cooling the environment through evapotranspiration. The extent to which vegetation cools the urban climate depends on species selection and strategic placement (Doick and Hutchings 2013). Urban vegetation can change the localized air temperature and air quality through several mechanisms, including evaporative cooling and evapotranspiration, reflectance of radiation, which is linked to surface albedo, as well as through shading (Doick and Hutchings 2013).

The IoT and other technology implementations such as WSNs contribute in many forms and applications to reducing pollution in urban planning strategies. Through the IoT, the physical world is becoming an information system with sensors and actuators embedded in physical objects and connected to one another and to central servers wirelessly or through wired connections. The IoT provides the potential of improving the productivity of the production processes in industry by governing and adapting to take corrective action automatically and in much shorter times (a few milliseconds potentially) compared to human operators and maintenance workers.

Further honorable mentions, as presented in Fig. 6, include effective implementation and sustainable strategies of recycling, endeavors to increase community awareness of sustainable urban planning to reduce GHG emissions resulting from increases in industry and positive economic growth.