India's building construction industry is witnessing remarkable growth trends, particularly office spaces. Estimates suggest 80% of the buildings that will exist in the year 2050 is yet to be constructed. Building industry is responsible for 35% of total energy consumption in India. In order to achieve India's 2030 goal of installing 500GW of renewable energy to its grid and to meet the larger goal of climate strategy of lower carbon emission, optimized strategies in designing High-Rise Net-Zero Energy Building is required.
The aim of this research is to create an integrated decision-making strategy for achieving Net Zero Energy in Varied Sizes of Office Spaces, by identifying strategies that are both energy and cost efficient. The proposed integrated design approach is applied to three varied sizes of high-rise office buildings; bifurcated as Small Office Building comprising of four-floors having 500m² floor plate area, Medium Office Building comprising of 10 floors having 1500m² of floor plate area each and Large Office Building having 20 floors of 2500m² of floor plate area each, located in Ahmedabad. Energy simulations were done using Design-Builder software (EnergyPlus tool). The availability and cost of the materials and equipment were assessed with a market study.
The maximum energy savings achieved with prescriptive compliance through ECBC-Super measures as mentioned in ECBC-2017 for all three building types, having 20.6% savings for Medium Office, 17.6% for Large Office and 17.15% for Small Office type as compared to Business-as-usual case. The incremental cost and Net-present Value for all nine cases; i.e. three building type and three stringencies of ECBC-2017, were compared and, energy conservation measures prescribed for 'ECBC minimum' are the most optimum solution for all cases.
Based on the impact of individual measures on all three types of buildings, the energy savings through Lighting Power Density is highest. It was also observed that, the impact of similar energy conservation measure of wall on Small Office Building was 2.44% greater than that of Large Office Building.
With current available technology of Solar PV, Net-Zero Energy is achieved with roof-top solar PV in Small Office Type, combination of roof-top and BIPV will attain Net-Zero in Medium Office and additional area to roof with the combination of roof-top and BIPV will help attain Net-Zero in Large Office type. The future technology of Solar Photovoltaic would require up-to 30% less area to achieve Net-Zero Energy in buildings.