Building energy retrofitting consists of wide-ranging energy efficiency measures such as improvement in envelope through incorporation of insulation, efficient buildings windows, air tightness, use of efficient appliances and lighting systems, upgraded HVAC system, and more effective operating regime.

The retrofitting strategies are as follows:

Remarks	Most Preferred	Preferred	Least Preferred
Energy Saving Potential
Payback Period
Disturbance to Occupant
Project Duration
Execution Difficulty
Expert's Choice