Sustainable Building Features
The construction of green buildings is perhaps the most direct example of construction actions that benefit the city in the long term. A green building is a structure that reduces its impact by being resource efficient and environmentally responsible over the course of its life-cycle. They provide the same benefits as conventional buildings, while simultaneously protecting the environment, improving human health and well-being, and conserving valuable resources like water and energy. In extreme cases, green buildings are even able to regenerate natural systems by protecting habitat, cleaning water or harvesting renewable energy.
Some of the more common features of green buildings include:
- Energy Efficiency
- Renewable Energy Generation
- Water Efficiency
- Stormwater Managment
- Superior Indoor Environment
In Canada, buildings account for more greenhouse gas emissions than any other sector. This is largely because we have a relatively cold climate, and our buildings use a lot of energy to warm their interiors and keep us comfortable. Much of this energy is produced using fossil fuels, like natural gas, and so the more we use to heat our homes, the more GHG’s we are emitting. Limiting the heat energy lost through the day-to-day operations of a building can have a phenomenal impact on reducing its GHG emissions.
One of the best ways to reduce heat energy loss is to utilize a high performance building envelope to minimize heat transfer between the interior and exterior of the building. The building envelope is the exterior ‘shell’ of the building, and includes the walls, roof, windows, and doors. High performance envelopes generally employ windows and wall insulation with higher R-values than conventional buildings. An R-value measures a material’s ability to prevent heat flow, where a low-value material like metal transfers heat much easier than a high-value material, like the fabric in your oven mitts. Insulated envelopes are effective at conserving energy throughout the entire year as they keep the heat in during the winter and keep it out during the summer.
In addition to using high quality windows and insulation for your building envelop, preventing air leakage is another way to reduce the energy demand for the building. Retaining warm or cool air inside the envelope saves energy because the building’s heating or cooling systems do not need to work as hard to maintain a consistent temperature. Using a heat recovery ventilator (HRV) will allow you to capture heat energy escaping from the building and further lighten the load on your mechanical systems. You can use Natural Resources Canada’s Keeping the Heat In guide to learn more about how insulation, air leakage, and building envelopes improve the energy efficiency of a green building.
Installing energy efficient lighting and appliances will also reduce the energy consumed by the building, but remember conserving energy requires more than simply using energy efficient technologies. If the people living and working in the building do not lead energy efficient lifestyles, then only so much can be done to reduce its environmental footprint.
While using a good building envelope to prevent heat energy loss is a very common feature of green buildings, some also take advantage of renewable energy generation to supplement their energy supply and reduce their environmental footprint. This is commonly done using solar thermal or photovoltaic panels. In BC, switching from natural gas to electric heat will also reduce the footprint of your building by taking advantage of the province’s decarbonized electricity.
A high performance building that has supplemented energy efficient mechanical systems with renewable energy generation has the potential to be considered a net-zero building. While the term ‘net-zero’ is used in different contexts for building science, such as net-zero waste or net-zero carbon, it is most commonly used to refer to the building’s energy usage. Net-zero essentially means that you are getting the same amount out that was put in. When referring to energy in a building, it means that the building generates an amount of renewable energy equal to or greater than the amount it consumes over the course of a year. Net-zero energy is considered the peak of building performance, as it decarbonizes its greatest source of GHG emissions (energy usage) and actually produces extra electricity that is used to supply the electricity grid.
Producing electricity for the grid is an example of how net-zero energy buildings can be considered regenerative construction. Renewable energy generation is a service provided by the building that benefits the community beyond simply reducing its greenhouse gas emissions. Builders interested in constructing net-zero buildings should read the solar ready guidelines from Natural Resources Canada. The guidelines provide a framework for building ‘net-zero ready homes’; which are fully constructed buildings that simply need to be outfitted with an appropriate renewable energy system in order to achieve net-zero.
Conserving potable (fresh) water is another important feature of green buildings. Even in Metro Vancouver, where we receive huge amounts of rainfall and our freshwater reservoirs are supplied by alpine snowpack, water is a precious resource that should not be wasted. Water conservation will become even more important in the coming decades, as rising temperatures and climate change cause summer droughts to be more intense and last longer.
There are two main ways that green buildings conserve potable water through their operations. The first is to use water more efficiently. With low-flow water fixtures, you are able to use less water to complete the same job, like flushing the toilet. You can use this guide (PDF) to learn more about low-flow fixtures and other sustainable plumbing practices. The other method of conserving water is to take advantage of alternative water sources like rainwater or greywater. Using alternative water sources for tasks like flushing toilets and irrigating lawns allows the green building to retain high-quality fresh water for essential tasks, like drinking and cooking.
For many Canadians, water use increases in the summer because more is being used outdoors for tasks like washing cars and watering lawns and gardens. These tasks are typically inefficient, and using greywater or rainwater is an effective way to prevent valuable fresh water from being wasted. Conserving water is most important in the summer because droughts prevent our freshwater reservoirs from replenishing at the same rates as other times of the year. Another good way to reduce your outdoor water use is to plant a water efficient lawn or garden. Using native or drought tolerant plant species will allow you to keep a beautiful yard space without wasting large amounts of water.
Learn more about our waterworks systems here at the City of Maple Ridge.
Another feature of green buildings is the way they manage stormwater from heavy rain events. One of the more substantial impacts of climate change in Metro Vancouver will be an increase in rainfall during the fall, winter, and spring months. Many green buildings are able to capture this rain and treat it or use it as an alternative water source for gardening or cleaning. Taking advantage of the natural resources provided to us will go a long way towards helping us conserve our dwindling water supply.
One of the reasons why stormwater management is so important for green buildings is because conventional development utilizes an abundance of hardscapes; impermeable surfaces like roof tiles and pavement that prevent water from being absorbed into the ground. This is why developed areas are much more prone to flooding than natural areas. Plant species and greenspaces naturally absorb and retain water, slowing down the flow and preventing it from accumulating in large volumes. When stormwater is not properly managed, runoff containing pollutants can contaminate soils or nearby waterways. Additionally, flooding caused by water accumulated in large amounts can erode soils and damage ecosystems. It can also cause significant damage to human property, and harm human health and wellbeing. Use this guide to reduce the risk of your home’s basement flooding. Taking action before it is needed will help to mitigate the costs that would occur in the event of a disaster.
In addition to planting greenspace, there are several other strategies that green buildings use to manage stormwater. Green roofs are among the most common and effective, particularly in high-density, urban areas. Green roofs are essentially greenspaces installed on the top of a building. This prevents runoff from the building’s roof and has the added bonus of maintaining a cooler temperature beneath it, which helps to conserve energy. Installing permeable pavement instead of conventional hardscapes is also a sustainable development strategy. The more permeable surfaces there are within a developed site, the less stormwater runoff is produced. This prevents pollution from contaminating local ecosystems, and reduces the risk of a potentially dangerous flooding event.
A prominent goal of many green buildings is to improve the health and wellbeing of its occupants. North Americans spend up to 90% of their time indoors, and so ensuring that these environments do not negatively impact the health of people living, working, and playing within the building is very important. Some features that improve the indoor environment include ample amounts of daylight, good acoustic performance, high quality views, and excellent indoor air quality.
The indoor air quality is perhaps the most important of these features. Particularly in buildings with tight envelopes and limited air leakage, contaminants will persist inside the building for long periods of time. This means that the people inside are constantly exposed to the pollution, leaving them at a greater risk of health complications because of it. If the building is not properly sealed against moisture, mould or mildew is likely to begin growing. The spores of these fungi can cause allergic reactions and severely reduce indoor air quality. It is recommended that a mechanical HVAC (Heating, Ventilation, and Air Conditioning) unit is used to maintain the indoor air and environmental quality. The HVAC system acts as the ‘lungs’ of your green building, allowing the tight building envelop to conserve energy and maintain a comfortable temperature, while also supplying the interior with clean, fresh air to maximize comfort.
- Green Transportation Capacity
- Sustainable Materials
- Effective Waste Management
- Easy and Efficient Maintenance
- Site Sustainability
Solid waste should also be properly managed. During both building construction and operation, waste materials that can be composted or recycled should be diverted from the waste stream and properly disposed of. This helps form a circular economy where waste is reused and recycled into new materials; reducing the amount of things that are left sitting in landfills year after year.
For developments involving new construction, the site of construction should be selected in a way that minimizes the environmental footprint of the building. This means that sensitive areas like wetlands and prime farmland should not be considered for the building’s location. Natural habitat should also be conserved and even maximized as part of the building design and construction. Building renovations and retrofits should try to reduce hardscapes and restore greenspace and natural habitat.