New regulations on fire safety and the installation of solar panels, including those on rooftops, will soon be unveiled.
The Singapore Civil Defence Force (SCDF) confirmed to The Sunday Times it will issue a circular to the industry next month that specifies the new rules.
They include requiring buildings to have at least two exit staircases from the rooftop before solar panels can be installed there, to aid firefighting efforts.
The new rules were first reported by website Eco-Business, and the SCDF said they will take effect six months after the circular is issued and apply only to new solar panel installations and not completed ones.
The SCDF said if there are physical challenges in making a building compliant, building managers can propose other fire safety measures, and it will review them.
Currently, rooftop access of many buildings is via cat ladders, which are usually narrow and cannot accommodate the transport of equipment.
Assistant Commissioner Christopher Tan, director of SCDF's fire safety and shelter department, said existing ladders to rooftops are for maintenance works.
"We don't believe they are robust or strong enough for firefighters carrying equipment, especially if you have a few firefighters climbing up.
"Speed of access is another consideration," he told The Sunday Times.
With solar systems becoming more widespread here and larger in scale, the new fire safety rules are needed, said the SCDF.
Solar energy companies here, however, are decrying one of the upcoming new rules, which they said could cripple the growing use of solar power in Singapore.
While they recognised that safety is paramount, they noted that solar panel fires are rare worldwide. There are also less onerous means of ensuring firefighters' access to rooftops, such as by installing or widening existing ladders, they added.
A main concern cited by the industry is whether buildings can be retrofitted to have the staircases, since building designers would have maximised the use of their designated space.
Even where such retrofitting is possible, the staircases will add 10 per cent to 50 per cent to the cost of solar panel systems, making them too expensive and unattractive compared with just tapping the national grid for electricity, the firms said.
Solar power has been more widely used in Singapore only in recent years, after prices of solar panels fell, making the cost of solar power competitive with that of drawing electricity from the grid.
Dr Thomas Reindl, deputy chief executive of the Solar Energy Research Institute of Singapore (Seris), said: "These proposed measures would go beyond what is practised in other countries where solar power has been deployed in large quantities."
Seris, the national institute for applied solar research, said it was not involved in drafting the proposed rules. Seris and several of the largest solar energy firms here - including REC, which has a plant in Tuas - said they learnt of the new rules only recently, though some less onerous rules were proposed to some of the firms last July.
The SCDF said it had consulted the Fire Code Review Committee and the SCDF Fire Safety Standing Committee before drawing up the rules, which also include safety standards for solar panels.
The committees include representatives from the Building and Construction Authority, Housing Board, groups such as the Singapore Institute of Architects, Institution of Engineers Singapore, Institution of Fire Engineers Singapore, and universities here.
The solar energy firms called for more consultation with the industry, and a task force comprising the authorities, the firms and more neutral experts such as Seris, which has acted as a mediator between the industry and the SCDF in the past month, to look into best practices globally.
Said Dr Reindl: "The safety of solar panel systems is a crucial pillar in making solar power a reliable and trusted source of energy in Singapore.
"We believe we can summarise the lessons learnt from other countries and apply international best practices to... Singapore, to come up with effective but reasonable measures."