SINGAPORE — All future public housing blocks with at least 400 sqm of open roof space will be designed with solar-ready roofs, the Housing and Development Board (HDB) announced on Friday (Sept 1), as part of plans to harness solar energy to power common estate services.

What this means is that HDB blocks will come inbuilt with features to enable solar panels to be easily mounted and maintained for future use, said the HDB in a statement.

The move comes following successful trials. In May 2012, Punggol Edge, a Build-to-Order development was the first to be designed with solar-ready roof, which allowed solar panels to be seamlessly installed on the roofs of six residential blocks in June 2016.

The pilot was further extended to 27 blocks at Punggol Northshore (Northshore Residences I and II and Waterfront I and II) in April 2016.

Making the roofs solar-ready will minimise the need for hacking and rewiring works when solar panels are installed, with the electrical infrastructure and trunks catered for in the building stages, HDB added.

Currently, installing solar panels on existing rooftops may require retrofitting and construction works, especially for older HDB blocks.

With such a "plug-and-play" approach, the HDB said about 25 days are required for the installation of solar panels on a solar-ready roof, compared to 40 days required to retrofit existing blocks.

Manpower cost for installation is also expected to be reduced by more than 40 per cent.

As of August, 18 HDB projects around Punggol, Bukit Batok, Sengkang, Hougang, Bedok, Kallang, Bidadari and Tampines have been designed with solar-ready roofs.