As an AI language model, I don’t have the latest data and statistics regarding all the countries who have implemented successful initiatives to promote sustainable and energy-efficient retrofitting of existing buildings. But, according to the various reports, some of the countries who have successful initiatives to promote sustainable and energy-efficient retrofitting of existing buildings are:

1. Germany
2. Denmark
3. Sweden
4. Norway
5. Canada
6. United States
7. United Kingdom
8. Australia
9. Japan
10. France

These countries have implemented policies, programs, and initiatives ranging from building codes, energy labeling, tax incentives, government grants, and financing options to encourage property owners and tenants to retrofit their buildings with sustainable and energy-efficient technologies, such as insulation, windows, HVAC systems, and renewable energy sources. These measures have proven to be effective in reducing energy consumption, lowering greenhouse gas emissions, and improving the comfort, health, and productivity of occupants.