The concept of carbon pollution is typically associated with the transportation sector. When we talk about air pollution, we tend to imagine a large number of vehicles stuck in traffic, releasing emissions into the atmosphere. However, buildings actually have a higher environmental footprint than transport, although it is less obvious.
Buildings produce pollution directly and indirectly, accounting for 39% of carbon dioxide emissions, according to the US Green Building Council. Transport is in second place, with 33% of emissions, and industrial activity is in third place, with 29%.
Make your building greener and reduce energy costs.
Direct emissions from buildings
Buildings release carbon dioxide directly when using equipment that relies on combustion. The following are some of the most common examples:
- Boilers and furnaces used for space heating consume fuels such as natural gas and heating oil. New York City has banned the heaviest types of oil, #4 and #6, as they have the largest carbon footprint – only natural gas and the lighter #2 heating oil are allowed.
- Water heaters also use the combustion of fossil fuels as a heat source. For a given load, storage tank heaters use more energy than instantaneous tankless heaters and, as a result, their emissions are also higher.
- On-site power generation also contributes to building emissions if the energy input is a fossil fuel. For example, both diesel generators and steam microturbines produce emissions, although the impact per kilowatt-hour is typically greater with diesel.
All the functions mentioned above can be performed without the combustion of fossil fuels. For example, heat pumps can replace conventional boilers, furnaces and water heaters without local emissions, using only electricity. On the other hand, wind turbines and solar photovoltaic systems are viable for electricity generation and can be combined with energy storage to compensate for wind and sunlight variability.
Indirect emissions from buildings
Not all emissions attributed to buildings are produced on site. For example, if you have a property where all heating systems run on energy-efficient heat pumps, no emissions will be produced locally. However, if the electricity supply comes from power plants fired by natural gas or coal, the heating systems continue to produce emissions indirectly.
Indirect emissions can also be attributed to heating systems that use the combustion of fossil fuels. In addition to emissions produced with direct combustion, there are indirect emissions associated with the extraction, processing and delivery of fossil fuels to the building.
Building electrification is important because it removes local emissions, but complete decarbonization also requires a transition to clean energy sources. With electrification alone, emissions are simply being transferred off-site; this mitigates their impact on human health because they are removed from urban areas, but environmental damage remains.
New York City: Leader in Green Building
New York City provides an example of how governments can take action to decarbonize the construction sector. The ambitious 80x50 plan aims for an 80% reduction in city emissions by the year 2050, compared to 2005. Additionally, the Greener Large Buildings Plan (GGBP) introduced several laws to make buildings more efficient, including Local Law 85, which created the New York Energy Conservation Code.
Energy efficiency measures are among the most cost-effective ways to reduce emissions, as they provide a financial return for building owners. The same can be said for on-site renewable generation systems such as solar panels and wind turbines.
