Sustainability Consultant Jomin Varghese of Transven Consulting proposes the importance of early stage design decisions as the way to achieve sustainable green buildings at lower costs
With the green movement gaining prominence in India, green building footprint has now grown immensely in the last five years as compared to historic data. Green building certification helps to identify whether a particular structure is environment friendly and is sustainable in terms of its design and orientation. It takes into account metrics such as water efficiency, energy efficiency, CO2 emission reduction, indoor environmental quality, innovations in design and more to determine whether a building is worthy of green certification and at what level. LEED, IGBC, GRIHA are the most adopted third-party verification programs.
Certification is important, but it is just the beginning. Sustainability beyond certification is important so that maximum green strategies are incorporated within budget at the concept stage with optimised use of natural resources available on the site. In fact, we should look at sustainability from a holistic perspective where design, construction and operation are fused to achieve sustainable performance. Building a sustainable green building entails precise analysis of the master plan, floor plan, the room plan et al. Some of the prominent factors which are considered include:-
A) Climate & Wind Study
Analysis of the climate & wind patterns helps designers to arrive on passive design strategies to meet their sustainability agenda. It is important to understand that sustainable buildings do not have to incorporate technologies such as wind turbines and photovoltaic cells; a thorough analysis of the site on a strategic level will expedite the genesis of a design which can integrate natural systems of heating, cooling, lighting and ventilation.
B) Orientation and Building Form Analysis
Form and orientation have huge impact on buildings energy consumption. Buildings with precise orientation consume 20 – 50% less energy. It helps to harness free wind & sun energy and reduces operational and capex cost on HVAC.
C) Solar Insolation Analysis and Open Space Assessment
Solar Insolation analysis helps in understanding the amount of sunlight hours available on site and building during different period of the day all over the year. Thus, space planning for regularly occupied spaces and non-regularly occupied spaces can be determined and artificial lighting can be reduced. These analyses also aid to identify the shadow strategy as applicable to the different blocks to their respective facades. Similarly organization of pedestrian walkways and other amenities can be done in accordance to the functions and activity expected and proposed to be promoted through design.
D) Sun Path and Shadow Analysis
By analysing the impact of the movement of the sun with respect to the building, the designer can take full advantage of passive solar design features and increase the energy efficiency and comfort of the building occupants.
E) Daylight Analysis
It helps to analyse the amount of daylight on the floor plate and helps designers to take quick design decision on façade options for optimizing day lighting thus improving occupant comfort and reducing dependence on artificial lighting.
F) Envelope Analysis
The objective of this study is to achieve an optimized skin i.e.: façade & fenestration, skylight solution by use of active and passive measures that shall help to reduce environmental and carbon impact of the development. The façade analysis is performed to reduce solar heat gains, improve occupant comfort, and provide a feasible choice between installations of construction materials for different zones, Improve natural daylight for spaces.
G) Thermal Heat Gain Analysis
Zonal Analysis of various areas to understand the various factors that contribute towards the heat gain and thermal discomfort, and suggestion of strategies to reduce the HVAC load requirements.
H) Natural Ventilation Strategies
Natural ventilation uses natural outside air movement and pressure differences to both passively cool and ventilate a building. Better natural ventilation strategies are determined by having high thermal comfort and adequate fresh air for the ventilated spaces, while having little to no energy use for air conditioning and mechanical ventilation. This can be a large fraction of a building’s total energy use. You can choose the right strategy based on the geographic location of the building.
I) Post Occupancy Evaluation
Post occupancy survey from occupants helps to identify and justify perusal of certification program to achieve sustainable development and also explore additional measures to enhance customer experience in future projects of the company. A collated study of savings from various energy factors that influence design and observations from occupant engagement would serve as a guide and provide insight to decision makers and highlight areas where returns on efforts have not been realized.
Al Jamea tus Saifyah – Residential School Campus
Al Jamea tus Saifyah, an upcoming 3 acres Project at Marol, is one of the well-known educational institutes of the Dawoodi Bohra community. Some of the strategies suggested based on the analysis conducted were:
• Wind flow in Passages surrounding courtyard was optimised using stack ventilation strategies
• Concave light reflectors along with vertical and horizontal shading devices were proposed for improving daylight and reducing glare in library areas
• Passive ventilation strategies were suggested for densely occupied spaces like religious areas and multipurpose halls
• Sun shading devices such as solar panels were suggested to providing shading to specific outdoor areas with high solar radiation during the afternoon and early noon hours. Additionally the space can be used for outdoor teaching and recreation activities for the students during the day time.
• Light tubes were suggested to provide daylight to interior areas which are not directly facing the outdoors
• Space planning for regularly occupied and non-regularly occupied spaces based on the maximum daylight availability throughout the year
Elcome Headquarters– Commercial Office Building
Elcome Integrated Systems Pvt Ltd proposes to build their corporate headquarters in Mahape, Navi Mumbai. The proposed development is a single office building with an approximate built up area of 92,324 sq ft
Some of the strategies were:
• Determining the size and height of the skylight for maximum daylight penetration to all the floors to reduce artificial lighting.
• The facade design and fenestrations were suggested to reduce glare, heat ingress and achieve thermal comfort
• The central multi-level atrium to be used as a ventilation shaft to passively ventilate connected passage and circulation areas by openings on the top of skylight. This air circulation will be driven by buoyancy driven stack ventilation
With the rising tide of global warming concerns and environmental impacts, building green is the need of the hour, and simple passive design strategies and right decision making can help us in the long run.