The construction industry is growing annually at a rate of 4.5% to meet the present day need for housing and infrastructure. On the other hand, the impact that a building creates on the natural environment is startling.
The study shows that in the US, buildings consume around 40% of the total energy, 70% of electricity, 40% of raw material and 12% of water supplies, leaving behind 130 million tons of construction and demolition waste. Beyond this, it accounts for 30% of greenhouse gas emission.
The concept of Sustainable or Green building has evolved to mitigate this negative impact of building and construction. AEC firms follow the Green building process, right from the inception of a project, from planning to design and construction, including operation, maintenance renovation, and demolition. The objective is to keep a check on the building performance and make it environmentally, economically and socially responsible.
Four major factors to be dealt with for a sustainable or green building are material, energy, water, and health. Materials used for construction needs to be assessed on specifications like energy, durability, recycled content, waste minimization, and their ability to be reused or recycled. For energy-efficient and environment-friendly lighting; Passive solar design is incorporated in green buildings with the use of renewable energy technology like solar panels and wind turbines. Water management techniques like Rainwater harvesting and the use of water-efficient appliances are followed. Non-toxic materials are used in the building to maintain Indoor-air quality to control the health factor.
The Go-Green trend is on an upsurge in the AEC Industry. The Smart Market report released by US Green Building Council (USGBC) shows that by 2021, 57% of the building owners are planning to make their projects green. Nearly, half of the 19 participating countries in the survey, is going to make more than 60% of their overall project as green buildings by 2021. The green building market is estimated to be of $ 1.4 billion by USGBC.
BIM - A simplified Process for Constructing Green Buildings
BIM, as a sustainability tool, is practiced in the AEC Industry to achieve the agenda of green building. BIM software integrates and analyzes, the environmental and sustainable factors with the 3D model of the project to evolve a sustainable design.
What Is BIM?
BIM is a digital representation of a project, showcasing its physical and functional characteristics. BIM models files can be extracted and shared with stakeholders to support decision-making for better project design. BIM is not only limited to 3D representation, but it also has a fourth dimension (4D) as time and fifth dimension (5D) represents the cost. The sixth dimension (6D) includes environmental and sustainability analysis, while the seventh dimension (7D) is lifecycle facility management. With BIM, a building can be planned, designed, constructed, operated and maintained throughout its life.
Because of these specific features, BIM is widely acknowledged in the AEC Industry.
Generating and Giving Access to Reliable and Consistent Information
Because of the BIM's multi-dimensional approach, the workflow of a BIM project can be smoothly collaborated, replicated and reviewed at each stage. It generates reliable and consistent information that can be shared in real-time using a common database. This results in benefits like early clash detection, waste reduction, resource-efficiency and fast delivery of the project.
Drawing are Integrated with Project data
With the digital view of the BIM project its performance, property, and function can be visualized and analyzed. The software tool integrates all the aspects and elements of the project in the model, the drawings developed are precise and accurate. This includes the engineering details, materials specifications, and overall performance of the model.
BIM develops a design on parametric modeling, which is based on an algorithm or pre-programmed rules or parameters. It enables BIM, to create a relationship between different elements of the design. For example, a change made to a particular element with a parametric attribute such as color, positional data or other dimensions then it will be automatically updated throughout the model with the same parametric attributes.
Significance of BIM in Green Building
Integrating several environmental factors in the 3D model, provides a broader context for analysis and decision making. Green BIM handles various impediments while implementing the sustainable strategy in the building.
Gauge the Building Structure, Material and Performance for Sustainability at Several Phases
By consolidating the sustainability factors from the inception of a project, BIM goes through the building structure, material, performance and other aspects of the green building to enhance the sustainability of a building.
Design Phase - BIM facilitates an effective collaboration and coordination platform for the project team. The team can brainstorm on the project's sustainability goal with access to a common and open source of the project database. 3D visualization and an insight into the environmental factors like sun, wind, rain and other elements helps in achieving the green design model. Real-time design change facility supports to get the best design alternative. Specifications of the materials can be extracted from the model by analyzing and evaluating a sustainable performance like Energy efficiency, Lightning, Indoor Air Quality, water efficiency, and others. Through Energy modeling, the energy efficiency of a building can be enhanced with optimum use of renewable resource and reduction in energy consumption.
Construction Phase - The 3D model makes the construction phase accessible and fast, by providing design and sectional details. It improves the safety of the construction process and reduces the operation cost by reducing any construction defects. BIM tools lessen environmental pollution, energy consumption, and other hazardous environmental effects while constructing. Offsite fabrication reduces waste generation at the site.
Operation Phase - Access to the sustainability information results in tracing performance of the building on factors like energy consumption, carbon emission, water management, or wastewater treatment, etc. Continuously, the building’s lifecycle performance is monitored and improved.
Integrates Digital Model with Energy Analysis Tools
Energy Analysis - For energy analysis of the building, BIM Software (Revit) can tie up with Energy Analysis tools like Green Building Studio right from the design phase. It helps the designers to create an energy model acknowledging, weather conditions, carbon emissions and pollution, water usage, HVAC and ventilation, lightning and other major factors.
Topography Modeling - Topography modeling strategies the building design in terms of day lightning, solar heat gain and passive electricity generation through solar energy. The passive energy generation reduces the external burden of electricity, light and heat consumption of a building. Select a site with Solar and Shadow analysis, design structure with maximum natural lightning, leverage on exterior bounce light between buildings and optimize energy consumption with BIM tools.
The Miami Science Museum: An Illustration of Sustainable Design with BIM Modeling
The Miami Science Museum a cultural, educational and research science institution built on the Miami Water Front is an example with the impeccable use of BIM for Green Building. The MiaSci project has used BIM to maximize the use of solar and water resource and managed effective ventilation and air flow with building the shape.
The model integrates the active and passive solar design strategy, contemplating the location and direction of the sun. Solar panels are fixed at the roof and façade to harness the solar energy. Thin film PVs and skylights are also used for power generation. BIM designed the building with the solar conditions throughout the year and Passive Solar strategy provides a mode of heating as well as cooling.
MiaSci has made a water catchment feature, on the roof and its car parking area for Rainwater harvesting. The Green roof and green walls also help in collecting the rainwater which is later used for irrigation. The excess water is directed to the wetland and injection wells. Water collected is treated with natural bio-filtration methods like mangroves, openings and green roofs and green walls. Efficient water management is performed by using treated water from basins, showers and other parts for the toilets.
Air flow and Ventilation
Using BIM, MiaSci building is shaped and designed to work with wind flow pattern at the location. The buildings, north and south solid block boundary and southwest orientation is designed to capitalize the wind flow. Further, the museum’s size, height, roof, and other openings, is constructed with a close analysis of the wind velocity, cross-ventilation, and air flow.
Benefits of Practicing BIM for Green Construction
Offers a cohesive view of the project - The best property of BIM software is to simulate various components of a building in its digital view along with environmental factors, leads to the transparency of information, better analysis and decision making with finer building design.
Better collaboration with stakeholders - Transparency of information at the design stage not only benefits the Architects, Engineers, and Designers to collaborate smoothly, it helps in the supply chain with correct product, material, and chemicals information. The material used for construction should be LEED (Leadership in Energy and Environmental Design) standard and environmental friendly to achieve sustainability.
Easy Evaluation and calculation of Sustainable alternatives - BIM develops a Decision Support system(DSS) with the help of multiple criteria decision-making technique at the conceptual stage, this helps the team to easily evaluate and calculate the optimum building component and design alternative to achieve sustainability. The environmental, economic and social elements are the base to make the decision.
Reduction in Waste - BIM model creates a coordinative environment that supports to develop accurate documents and representations like drawing sheets, model views, schedules, and plan. An efficient building plan and practice help in reduction in waste at the design and construction stage.
Performance optimization - BIM provides necessary information to the facility managers about HVAC, Electrical, Structural, Plumbing, FF&E, IT and other complex facility elements to maintain and improve their function throughout the life- cycle of the building, leading to performance optimization and a better ROI.
Go Green with BIM
In a nutshell, BIM carries the potential of Sustainability Building by meeting the goal of Cost-effectiveness, reducing the negative Environmental impact and maintaining a process that considers the well-being of the people at work.