Retrofitting is gaining popularity as a sustainable alternative to new construction, offering significant environmental benefits. Case studies like the University of Cambridge's 'Entopia Building' highlight reductions in material usage, energy consumption, and carbon emissions.

Retrofitting can save up to 70% in carbon emissions, reduce waste, and improve energy efficiency, as seen in renovations like the Sydney Opera House. Modular rental building solutions, constructed offsite, also offer sustainability by being reusable and reconfigurable. 

To achieve Net-Zero targets, retrofitting and rental solutions need government support, such as investment in retrofit programs for housing and public facilities, including healthcare and education.