Glass Selection Comparison Case-1 (Usual Case)
Case DGU glass on all the facades
Energy Cost of Glass (Rs) Savings in energy Savings in Consumption (kWh) (kWh)/Year energy (Rs)/Year 1515100
Case-2 DGU on south and SGU 1530900 (Recommended on rest of the facades Case)
5029505
15800
158000
2992756.08
Difference in cost 2036748.92 of glass for both the cases
Return of Investment (Years)
12.89056164
The energy consumption of recommended case is more as compared to the other cases, but this case claims saving of more than Rs 2,000,000 approximately. If we go with case 1, i.e., the usual case of having DGU on all the facades of the building, the project will save approximately 15800 kWh a year i.e. (1.5 Lakhs per annum), which will make us to have the return of investment in around 13 Years. The total cost for applying DGU glass on south and SGU on the rest of the façade of the building is least of all the above cases, which is leading us towards a savings of more than Rs 20, 00,000. On the other hand however we are saving by 1.5 lakhs/ annum but our initial cost for the glass will be high, which will make an ROI of 13 years approximately Results: As per the comparative analysis of all the shortlisted glasses, the project should go with the case 2 by taking SKN-754 DGU glass on south façade of the building and SGU on Rest (Neutral Evolite ET 150 II) façade of the building, as with this case the savings will be around 20 lakhs.
So, the appropriate selection was DGU on south facade and SGU glass on the rest of the facades - East, West and North of the building. It was more feasible as it was helping the project to save more than 20 lakh rupees. If the project building would have taken DGU on all the sides, the investment would have been 20 lakhs more on glasses which will make the project to have an ROI of more than 13 years, which was not feasible. A healthy discussion among the architect, green building consultant and the owner lead the project with a very efficient façade design, which considers the above recommendation in a modified way. Now the project team has considered SGU glass on the north facade & DGU glass on the south facade. Whereas, for the east & west facade, DGU glass has been considered in the regularly occupied areas and SGU glass in the non-regularly occupied areas.
QUICK FACTS Project: Pinnacle Infotech Solutions Location: Jaipur, Rajasthan Architect: C.R. Narayana Rao (Consultants) Private Limited Green Building Consultant: Design2Occupancy Services LLP Landscape Consultants: Insape Design Studio Materials used for Facade & Fenestration: 50 mm XPS insulation in the roof & roof U- value is 0.383 w/Sq. m.K Commencement Date: June 2016 Completion Date: September 2017 (solar rooftop is in progress) Certification: The building documentation for LEED is under progress thereby yet pending.
40 WFM Jan - Feb 2018