[2] Sustainable refurbishment takes this a step further to modify the existing building to perform better in terms of its environmental impact and its occupants' environment.
Principally retrofitting describes the measures taken in the manufacturing industry to allow new or updated parts to be fitted to old or outdated assemblies (like blades to wind turbines).
Naval vessels are often retrofit for one of three reasons: to incorporate new technology, to compensate for performance gaps or weaknesses in design, or to change the ship's classification.
Many times smaller ships are retrofitted for patrol, coast guard, or specialized roles when they are no longer fit for duty as part of a warfleet.
For instance, the USS Langley was an aircraft carrier converted from a collier (coal-carrying ship to supply coal-fired steamships with fuel) of the Jupiter-class.
The term is also used in the field of environmental engineering, particularly to describe construction or renovation projects on previously built sites, to improve water quality in nearby streams, rivers or lakes.
The concept has also been applied to changing the output mix of energy from power plants to cogeneration in urban areas with a potential for district heating.
Sites with extensive impervious surfaces (such as parking lots and rooftops) can generate high levels of stormwater runoff during rainstorms, and this can damage nearby water bodies.