Illegal rooftop structures that obstruct fire escapes and pose other hazards to occupants in single staircase buildings will be removed by 2007.

Acting Director of Buildings Cheung Hau-wai said the rooftop of a single staircase building is a refuge area for occupants during a fire and should be unobstructed at all times.

He said the Buildings Department has stepped up enforcement against illegal rooftop structures on 4,500 single staircase buildings - a rate of 700 buildings a year.

At the end of last year, 2,956 illegal rooftop structures on 1,349 single staircase buildings had been demolished. Mr Cheung said the remaining illegal structures will be removed in stages.

In parallel, enforcement against newly erected illegal rooftop structures on all types of buildings will be taken immediately.

Mr Cheung reminded building owners the onus was on them keep their buildings free from unauthorised works.

If owners cannot afford to clear illegal structures, they can apply for the Building Safety Loan Scheme.