How are LCA and CAD Enabling Green Energy Home Designs?
A major goal in the manufacturing industry is to design products which have built-in sustainability and positive environmental impact. In particular, green building design involves finding a reasonable balance between homebuilding and the sustainable environment. Some of the primary goals of green building design are to:
- Efficiently use energy, water and other resources,
- Protect occupant health, comfort, and productivity,
- Reduce waste, pollution, and environmental degradation,
- Use as much as possible, natural and ecofriendly materials for building construction.
One way to fulfill these goals is to build sustainability into the product design from the beginning through the use of integrated LCA (Life Cycle Assessment) and CAD technologies.
The ability to integrate CAD/CAE and LCA during product design and development is a challenging task, because CAD/CAE involves design iterations, while LCA involves product evaluation and assessment. Fortunately, many CAD tools are available for making LCA and CAD/CAE work synergistically during product design and development. Fortunately, green enabling technology tools are provided by leading CAD software companies and other organizations.
This article discusses how LCA and CAD technologies are enabling Green Energy Home Designs. Specifically, the article addresses these topics:
- (a) Why is it difficult to integrate LCA and CAD?
- (b) Why is it necessary to integrate LCA and CAD for Green Energy home design?
- (c) Which software tools are integrating LCA and CAD?
Why Is It Difficult To Integrate LCA and CAD?
The difficulty in integrating LCA and CAD is due to the different approaches that the two technologies take for product design.
CAD focuses on designing a product which is functional, robust, durable, cost effective, and reliable. In order to do so, designs produced by CAD/CAE software usually go through several design reviews and iterations. Even after CAD/CAE software deliver an optimal design, it is possible that results from the prototyping and testing phase could necessitate costly design changes. Only after these design iterations have been completed will the hard tooling phase of the product begin.
The focus of LCA is sustainability, and it is concerned about the following:
- Eco-design principles should govern the initial design,
- Usage of eco-friendly design materials is a requirement during the design phase,
- Synergy should be maintained between design engineers and all other parties involved in product delivery,
- The environmental footprint of the product should be minimized.
Obviously the goals of CAD/CAE and LCA are different. Integration of the two technologies requires wise decision making between the two technologies in order to create a win-win situation.
Why Is It Necessary To Integrate LCA And CAD For Green Energy Home Design?
The purpose of Green Building (also known as Sustainable Building) is to have good balance between a building and the sustainable environment. In order for this to happen, the design teams, architects, engineers, plumbers, electricians, and all parties involved in a building project should work cooperatively during the design and construction phases of a building project. This means that the classical building design practice which previously focused on economy, utility, durability and comfort should be expanded to include environmentally friendly design issues.
Because the preservation of the environment has become a major issue globally, legislative bodies now exist which lay down regulations governing Energy and Environmental design. Highlights of the regulations governing Green Energy homes are that homes should:
- Be constructed or retrofitted if possible, with locally available and natural materials,
- Use water, energy, and other resources efficiently,
- Protect occupant health,
- Reduce waste, pollution (especially carbon dioxide emissions), and environmental degradation.
These regulations are easier to satisfy when LCA is applied consistently and faithfully during the design and construction phases of a building project. Important design issues raised by the application of LCA during the design and construction phases of a building include the following:
- Designers use locally available building materials such as wood, because the usage of embodied energy is reduced, compared with the usage of materials such as brick, concrete or steel. Embodied energy is required to extract, process, transport and install building materials
- Designers pay greater attention to reducing energy leakage by minimizing spaces between conditioned and unconditioned spaces. Designers also specify high performance windows and insulation in walls, ceilings, and floors.
- Designers use passive solar energy by orienting windows and walls relative to trees so as to provide shade during the summer and to maximize solar gain in the winter.
- Designers make provision for utilizing solar power, wind energy, or alternate forms of renewable energy.
Apart from using energy economically and efficiently, LCA addresses other design issues involving:
- Reduction in water consumption,
- Use of eco-friendly materials,
- Maintaining good indoor air quality by avoiding the use of toxic materials and by minimizing carbon dioxide emissions,
- Control of moisture accumulation which leads to mold growth.
Which Organizations and Software Tools Are Integrating LCA And CAD?
Apart from legislative bodies which set the rules, specifications and principles for Green buildings, it is worthwhile to mention a few organizations which are integrating LCA and CAD.
- The Athena Sustainable Materials Institute is a non-profit research institution which provides LCA guidance in product manufacturing. The primary goal of the Athena Institute is to enable smaller footprint in the production and consumption of construction materials. The Institute provides the Impact Estimator as tool for buildings. The tool provides engineers and analysts with access to advanced life cycle data without requiring advanced LCA skills.
- AutoCAD uses the software tool Ecotect which allows architects and engineers to measure a building’s performance criteria like solar, thermal, shading, lighting and airflow. Ecotect provides analysis very early on in the design process and does not require a completed building design to furnish performance data.
SolidWorks has CAD-embedded Sustainability software which provides actionable environmental results by measuring environmental impacts of individual designs across the product life cycle, including the effects of material, manufacturing, assembly, and transportation. The software uses industry-standard LCA criteria which help engineers and architects to reduce production costs and to develop greener products.