Some of the city's 500,000 illegal small structures are expected to be exempted from prosecution if they are proved to be safe under relaxed rules.
The Buildings Department yesterday proposed allowing flat owners to retain three types of small structures - supporting frames for air conditioners, drying racks and small canopies - which had failed to obtain approval from the Building Authority.
However, alterations, improvements or reinforcements may be required before the structures meet safety and dimensional standards, the authority said.
The proposal is to be discussed at the Legislative Council development panel next Tuesday.
The Buildings Department estimates there are 500,000 small structures illegally installed on buildings throughout the city.
The most common are unauthorised signboards, sheds built on platforms or roofs, and some household facilities.