Sustainability Assessment of Building System in Himalayan Region

Sustainability has become a global concern these days in order to reduce the environmental impact from the human activities (Passer, Kreiner, and Maydl 2012). Building sector stocks the emission from the energy consumed during the construction and operational phase until the demolition of the building (Scheuer, Keoleian, and Reppe 2003). It is important to quantify the environmental performance of the buildings in order to observe the potential environmental impacts and their influence on sustainable development (Sonnemann, Castells, and Schuhmacher 2003; Passer, Kreiner, and Maydl 2012).
This research work analyzed the environmental and economic impacts of building technologies and its efficiency in Himalayan region of Nepal through greenhouse gas (GHG) accounting in order to reduce the emission in the particular region. In the Himalayan touristic region of the Sagarmatha National Park and Buffer Zone (SNPBZ), the construction of modern buildings is growing fast, due to the increasing tourist flow. To satisfy the needs of the increasing tourist population, the traditional building design is modified, by replacing wood and stone masonry with reinforced concrete structure. Hence, the study on assessment of the environmental and the economic impact in the building system is important which gives an overall picture of the emission situation and helps identify the major emission sources and potential areas of improvement.
This research focuses on:
- The Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) of the Himalayan building with a functional unit of “One guest per night stay” to assess the environmental and economic impact of three existing types of building in the Himalayan region of Nepal on a life-cycle perspective. This motivates constructor, hotel owners, and tourist to choose the best eco-efficient building in the Park. The main aim of the study is to assess the environmental and economic impact of commercial buildings located in the Himalayan region of Nepal, from a life-cycle perspective.

- The research also presents the comprehensive overview of life cycle prospective both on environmental and economic aspect including physical and technical parameters such as energy consumption, thermal conductivity and size, over the entire hotel sector in the Park to accomplish building sustainability and promote the use of sustainable construction practice.

- The global warming potential of the building in the prospect of the Himalayan region with functional unit “construction and occupation” to compare the building in environmental and energy aspect in three different building types. This chapter concerns a study on the environmental assessment of buildings in Sagarmatha National Park (SNP), the Himalayan region of Nepal, where the high tourist flow encourages rapid development of the modern buildings.

- The Life Cycle Assessment of the Himalayan building with a functional unit of “1 m2 wall” to assess the environmental impact of building materials in prospect to the Himalayan building. This allows construction and hotel owners for decision making on constructing the environmentally friendly building. It provides a comparative life cycle assessment in terms of Global Warming Potential (GWP) of different wall materials used in traditional, semi-modern and modern types of buildings in Sagarmatha National Park and Buffer Zone (SNPBZ).

- The broad overview of environmental and economic impacts in the entire commercial sector of the park using statistic methods. It allows constructor, hotel owner or even tourist to choose the best eco-efficient building in the Park.

- The potential of GHG emission reduction in terms of household behavioural changes in the Himalayan region. It gives an overview of possible reduction of energy consumption in the Park, through the behavioral change on the consumption, which ultimately reduces the GHG emission in household level for the sustainable consumption.

The study consists of the life cycle assessment (LCA) and life cycle costing (LCC) of three building types: traditional, semi-modern and modern. The life-cycle stages under analysis include raw material acquisition, manufacturing, construction, operation, maintenance, and materials replacement. The result on LCA and LCC on the building types shows that the modern building has the highest global warming potential (kgCO2-eq) as well as the highest costs over 50 years of building lifespan. This is due to the use of the commercial materials that has to be manufactured and transported into the construction site instead of the traditional materials, which is available in the Park itself. Moreover, the operational stage is responsible for the largest share of environmental impacts and costs, which are related to energy use for different household activities. Furthermore, a breakdown of the building components shows that the roof and wall of the building are the largest contributors to the production-related environmental impacts. The findings suggest that the main improvement opportunities in the building sector lie on the reduction of impacts in the operational stages and on the choice of materials for wall and roof.
The study on the potential of GHG emission reduction in terms of the household behavioural changes in the Himalayan region shows that 6,094 t of CO2-eq per year can be reduced by following simple measures like keeping lid while cooking, using a pressure cooker for cooking, turning off the lights when not needed, reducing watching television etc. The reduction of CO2-eq emission in the region can also be achieved by encouraging the use of energy-saving activities like the efficient cooking and heating stoves and efficient light bulbs and use of a solar cooker for cooking also help to reduce the CO2-eq emission in the region. This study shows that the use of the bio-insulation made of local material can reduce the emission by 19% of the total emission.
On the basis of LCA and LCC results, it is concluded that the energy efficient building with the use of local materials in combination with proper insulation and renewable energy is the recommended option for sustainable building design in the Himalayan region. Energy-efficient technologies including cooking stoves, heating stove, light bulb and use of renewable energy have the major positive impact on the CO2-eq emission and should be encouraged in the Park. Sustainable building with the low energy consumption, high efficiency, and innovation in building construction, such as passive house should be promoted.
It is also revealed that the reduction of GHGs can be easily done with simple behavior changes without any compromises in daily household activities that should be encouraged in the Park. Information sharing and awareness program to the local people have to be conducted in this sector for effective results on GHG reduction. The results of this study will help to design the target-based policies related to behavioral changes in the household level to perceive the sustainable energy building that needs to be developed and implemented to reduce the local level GHG emission.