Buildings use energy, materials, water, and land to create the right environment for its occupants. All of these things cost money – and all of them have an environmental impact.
1. Material Use
Using more sustainable materials, using less material, and using materials in the right constructions can improve the environmental impacts of building construction, lifetime, and end-of-life.
Why it’s important
Materials have their own environmental impacts from extraction and production, and they also hugely affect the thermal, visual, and acoustic performance of the building. The choice of materials and building products also drives costs on projects.
Materials are also important because they create the physical space that your building occupants experience. Toxics or volatile organic compounds can negatively affect health. On the other hand, the right choice of materials can have positive emotional and human health implications.
Embodied energy or embodied carbon can be used as a measure of the environmental impact of a material’s extraction, processing, manufacture, and distribution.
However, over the life of a building and depending on the application, other factors like thermal and structural properties can be much more important. For example, better thermal properties of the materials used in a building’s envelope can improve the energy use (as measured by Energy Use Intensity, for example).
The lifecycle of the material is another important factor. Is it recyclable or biodegradeable? Is it made from recycled material or rapidly renewable materials?
Material selection is full of trade-off decisions, and effective strategies vary widely based on your goals and situation. It’s often a good strategy to re-use existing materials, source materials locally, and use recycled/recyclable materials.
2. Energy Systems
Energy systems produce, use, convert, and store energy for the building. In high performance buildings these systems need to be both efficient and effective.
Why it’s important
Systems for thermal and visual comfort all use energy in some form.
Energy production and use is the primary driver of greenhouse gas emissions and global warming. Energy use in buildings is also one of the biggest costs throughout the lifetime of a building.
Being energy effective means choosing the right technologies and design strategies for your building systems. This can be measured by looking at the kilowatt hours per year, per unit area (Energy Use Intensity or EUI).
Being energy efficient means getting the most out of the systems and technologies that you’ve chosen to use. This can be measured by the coefficient of performance of the equipment.
Energy system design should be looked at as a whole system. Depending on your location, needs, and the available sources of energy, you may choose to get your energy from on-site photovoltaic and wind, grid electricity, or natural gas. If you can’t get good clean energy on your site, you may be able to purchase offsets.
Generally, the architect’s work defines the energy “demand” (their design places requirements and constraints on how the building works) and engineers define how to “supply” this energy.
3. Water Use
Water is used inside a building for drinking, cleaning, and sanitation. It is used outside of a building for landscaping, and wastewater and runoff needs to be managed for a sustainable building site.
Why it’s important
Water is fundamental to human health and survival, and also plays a vital role in keeping ecosystems in balance. Shortages in fresh-water in some areas make water conservation even more important.
Water is measured in terms of both quantity and quality. The flowrate of fixtures like faucets and the storage capacity of tanks and cisterns are different ways to measure quantity.
Water quality can be measured in a variety of ways, and you need different qualities for different uses. Whether the water is potable or not dictates how it can be used. Indicators like pH, dissolved organics, suspended solids, and turbidity help measure quality.
Being effective with water is all about using the right kind of water for the right uses, re-using water as much as you can, and economizing use with high-efficiency fixtures as much as possible.
Capturing rainwater can be a great source of water. Also, plumbing systems that separate potable water, greywater, and blackwater can help get the most out of every drop. You can also purify the water on-site with living machines or advanced septic systems.