In 2003 the Green Building Council of Australia (GBCA) launched the Green Star environmental rating system. This was the first comprehensive method for evaluating the environmental design and performance of buildings based on criteria such as energy and water consumption efficiency, quality of indoor environment and resource conservation.

Aspen, as a committed member of GBCA, has taken the lead in the South Australian property industry with the adoption of 5 Star sustainable development standards, signifying 'Australian Excellence', across the City Central Precinct.

Tower 1, the first completed building, has been awarded a 5 Star Green Star – Office Design V2 certified rating, the first project in South Australia to achieve this standard. An application has now been made for a 5 Star Green Star – Office As Built Certified Rating.

The City Central project team undertook extensive research into sustainable and green building best practices across Australia and around the world. This resulted in the development, refinement and introduction of a range of innovations in sustainable design, technology and construction techniques methodologies on both Tower 1 and Tower 2. As a result, tenants have already experienced in Tower 1 significant opportunities for improvement in workplace practice and employee culture through better managed comfort conditions. The next tenants in Tower 2 and others in future facilities can also expect similar opportunities. Examples include:

• Potential reduction in staff costs through increased staff retention levels and enhanced attraction to the workplace for future employees. (source Lincolne Scott);
• Improvements in productivity relating to reductions in staff sick days, improved environmental comfort (both thermal and visual) and improved connectivity to the surroundings and empathy with the environment. (source Lincolne Scott);
• Market positioning and corporate leadership in relation to "triple bottom line" accountability;
• Reduced energy and water consumption provisions in outgoings budgets; and
• Up to 30% savings in annual air conditioning energy consumption using a passive chilled beam system as compared to traditional systems. (source Lincolne Scott).