To mitigate the Urban Heat Island Effect and improve the living environment through the introduction of greenery to public housing, The Singapore Housing & Development Board (HDB), National Parks Board (NPB) and UGL Premas have jointly developed a complete rooftop greening solution.

This solution, called the PEG (Prefabricated Extensive Green roof tray system), is suitable for most new and existing buildings in tropical countries. It is an innovative modular tray product that comprises of durable plastic trays with lightweight growth medium, suitable for an extensive green roof tray system.

The PEG is appealing for building owners and facility managers who are seeking a solution to extend the life of roof membranes and provide energy efficiency for buildings.

With an estimated eight million squares metres of rooftops in the tropical garden city of Singapore, an effective ‘greening’ system could pose a significant impact on the ‘urban heat island’ effect in which dense concentrations of city buildings attract temperatures that can go up to 10 degrees Celsius higher than surrounding areas.

The Memorandum of Understanding was signed in December 2004, and two project committees were formed to tackle the issue with a two-pronged approach.

Firstly, UGL Premas teamed up with NPB to look into the botanical aspects of selected native plants in Singapore and their performance in various growth areas and within different climatic conditions.

At the same time, the services of the School of Life Sciences of the Ngee Ann Polytechnic were engaged to conduct the investigative and laboratory works for the project. Their task was to identify plants species with the abilities to regenerate themselves and survive under a prolonged period of drought in Singapore’s tropical climate.

UGL Premas, together with HDB formed the second committee to look into the suitability of introducing a green roof system on most flat rooftops of the high-rise residential apartment blocks and multi-storey car parking structures commonly found in Singapore. The intent was to develop a prefabricated modular tray system which will be self-sustaining for plant growth and yet have the attributes of being lightweight, portable, and easy to install.

The manufacturing of all the synthetic components went into full swing in early November and the production of a full green roof tray system has now started, harnessing material resources from around the globe including Germany, China, Korea, Malaysia, Indonesia and Singapore.

After implementation at the public housing estate roof top, feedback thus far from residents who live near by the green rooftops has been very encouraging. They welcome more projects of this nature in their own neighbourhoods. It has certainly softened the landscape and has significantly cooled down the living environment.

The PEG System has received thumbs up from potential clients in the private and public sectors, as well as their consultants, and was recently awarded the Silver Award in the Enterprise Challenge 1st Public Service Creative Award from a group of 180 applications.