Thinking about the environment: Part two:
In part one of this blog, we discussed what should planning authorities require in any development plan to ensure clean and efficient use of energy (macro level). In this part we will continue to do so by focusing on the building units (micor level). We will also consider other environmental considerations that are relevant to sustainability in urban spaces.
Micro level: building units
In every building as a unit, we can achieve the net zero by making it NZEB ( Net Zero Energy Building). This requires finding a renewable source that is appropriate for the building and can sufficiently serve its needs, this will reduce CO2 significantly. (Marszal et al., 2011)
The passive house buildings are a good example for many reasons such as: very well insulated building. It can reduce and save a huge amount of energy by improving the building envelop (walls, roof, floor, windows, and doors). That means: “a maximum of 0.15 watts per degree of temperature difference and per square metre of exterior surface are lost.” (Passive House Institute)
And they have a good ventilation system that will improve the air quality and save energy. “at least 75% of the heat from the exhaust air is transferred to the fresh air again by means of a heat exchanger.” (Passive House Institute)
By addressing all the above issues, it will make the buildings energy efficient and even have healthier air circulation for people who suffer from allergies or respiratory diseases, hence, improving the living conditions of the residents while protecting the environment. (Feist et al., 2005)
Figure 4: Passive House Institute
There are three types of passive houses: passive house classic, passive house plus, and passive house premium. The image bellow will show how much energy consumed and generated in each one.
Figure 5: jgrovesmith, 2021
There are other important environmental considerations in this context though not directly related to renewable they remain an important aspect of environmental sustainability. Therefore, they should be part of any site planning, a key example is water conservation.
When Rain falls on surfaces in natural settings it seeps through earth, this process is referred to as infiltration and it is an effective natural drainage system.
However, natural infiltration is much less in urban environments since many surfaces are sealed off by asphalt and buildings. Therefore, in these urban settings surface water is diverted to nearby watercourses by manmade drainage networks. This has occasionally caused flooding and a decline in river water quality when dirty water spills into rivers as a result of sewers being overflowed by surface water. (Ferrans et al., 2022)
Figure 6: Sustainable urban drainage systems (SUDS) (Ferrans et al., 2022)
Sustainable drainage system (SuDS), which allows for storing rainwater, can solve many of these problems by reducing water flow rates and preventing it from contaminating fresh clean water. It can also allow for the reuse of the stored rainwater locally for toilets flushing or plants watering, in addition to improving biodiversity on the site. (British Geological Survey, 2023)
At the end it is best to think of the environment and sustainability as an integrated part of any planning, whether at local or national levels in order to make cities better living places for generations to come.
References:
(Marszal et al., 2011)
- Marszal, A. J., Heiselberg, P., Bourrelle, J. S., Musall, E., Voss, K. A., Sartori, I., & Napolitano, A. (2011). Zero Energy Building – A review of definitions and calculation methodologies. Energy and Buildings, 43(4), 971–979. https://doi.org/10.1016/j.enbuild.2010.12.022
(Passive House Institute)
- Passive House Institute, Passive House Requirements, available at: https://passiv.de/en/02_informations/02_passive-house-requirements/02_passive-house-requirements.htm
(Feist et al., 2005)
- Feist, W., Schnieders, J., Dorer, V., & Haas, A. (2005). Re-inventing air heating: Convenient and comfortable within the frame of the Passive House concept. Energy and Buildings, 37(11), 1186–1203. https://doi.org/10.1016/j.enbuild.2005.06.020
(British Geological Survey, 2023)
- British Geological Survey, 2023, sustainable drainage systems (SuDS), available at: https://www.bgs.ac.uk/geology-projects/suds/
Figure 4: Passive House Institute
- Passive House Institute, Passive House Requirements, available at: https://passiv.de/en/02_informations/02_passive-house-requirements/02_passive-house-requirements.htm
Figure 5: jgrovesmith, 2021
- jgrovesmith, 2021, classic, pluse, premium: The new Passive house classes and how they can be reached, available at: https://passipedia.org/certification/passive_house_categories/classic-plus-premium
Figure 6: Sustainable urban drainage systems (SUDS) (Ferrans et al., 2022)
- Ferrans, P., Torres, M. J., Temprano, J., & Sánchez, J. M. (2022). Sustainable Urban Drainage System (SUDS) modeling supporting decision-making: A systematic quantitative review. Science of the Total Environment, 806, 150447. https://doi.org/10.1016/j.scitotenv.2021.150447
