'We received a letter two months ago, [from the builder] telling us that our windows will be blocked. And they asked us to move our air-conditioners and pipes to the other side,' said a tenant living on the 12th floor.

'There won't be any light and air coming into the living room,' she said.

The hotel construction was approved by the Buildings Department - but so was the placement of air-conditioners and pipes on the older building, questionably close to the lot boundary.

It appears that when Wing Shun was built 40 years ago, its developers were so eager to make use of the investment, the building literally used every inch of the site's space.

Bernard Lim Wan-fung, professor of architecture at Chinese University, said the air conditioners and pipes were probably illegal constructions in the first place.

'No windows and facilities can be built on the side of a building which is close to the lot boundary,' he said.

'If they are built, the building should not be constructed close to the lot boundary. There must be space between these facilities and the adjacent building.'

Once the hotel is complete, three of the five windows of flat B units in Wing Shun Building will disappear, leaving those flats with only two windows facing the main street.

The hotel, developed by Bright Century Limited, is now seven floors high. Its completion date is unknown. 'It's now very noisy and dusty in the apartment,' the woman tenant said. 'Lights are on until 8pm or 9pm. That's very annoying.'

Flats on the lower floors are not affected, however. Their windows do not face the hotel project.

Lawmaker Kam Nai-wai, who is also a Central and Western district councillor, said four owners had complained to him so far.

Vincent Ho Kui-yip, chairman of the Institute of Surveyors' building surveying division, said buildings close to each other were common in Hong Kong.

Developers were allowed to build buildings within their own lot boundaries, Ho said.

He said the hotel developers had a right to ask that the older building's facilities be removed.

'In the first place, the old building should not have windows, air conditioners and pipes out of its lot boundary,' he said.

Bright Century project director Joe Liu said his company had first tried to approach property owners affected by the development a year ago. 'In fact, we have settled cases with three units already, to help them remove air conditioners and other facilities,' he said.

He said the hotel development had been approved by the Buildings Department, which assisted in talks with affected property owners. 'When our hotel is built, there will still be a 10cm gap between our building and the adjacent building.'

The owner of Flat B on the 9th floor said he felt humiliated when trying to negotiate with contractor Paul Y Builders. He said the contractor had only offered to pay half the expenses involved in modifications. 'They sent us letters and informed us what they were going to do. We are in a very weak position.'