Retrofitting is the process of adding new technology or features to older systems. It can happen for a variety of reasons, such as to improve functionality, energy efficiency, or appearance. Retrofitting is often used in the manufacturing industry to allow new or updated parts to be fitted to old or outdated assemblies. In construction, retrofitting is similar to renovation work, but it focuses more on building functionality than appearance. Retrofitting can add new items to the building, such as new technology, equipment, or building systems to improve the building overall. Examples of retrofitting projects include modern energy-efficiency elements, such as better windows, insulation, or other items which increase energy savings.

Retrofitting is an important part of climate change mitigation and adaptation, as it can help reduce the overall negative impacts of climate change by reducing building emissions and environmental impacts while also allowing the building to be more healthy during extreme weather events. Governments offer funding towards green retrofits as existing buildings make up a majority of operational buildings and have been identified as a growing area of consideration in the fight against climate change.

Energy-efficiency retrofits can reduce the operational costs of commercial buildings, particularly in older buildings, as well as help to attract tenants and gain a market edge. Retrofitting can also make homes more self-sufficient, through energy-efficiency measures like insulation and renewable energy, which helps to protect against rising energy costs.

In summary, retrofitting is the process of adding new technology or features to older systems, and it can happen for a variety of reasons, such as to improve functionality, energy efficiency, or appearance. Retrofitting is an important part of climate change mitigation and adaptation, and it can help reduce the overall negative impacts of climate change. Retrofitting can also reduce operational costs, attract tenants, and increase the value of a property.