THE Housing Authority should hire its own architects instead of relying on developers to maintain construction standards under the Private Sector Participation Scheme (PSPS), the president of the Hongkong Institute of Architects, Mr Dennis Lau Wing-kwong, said yesterday. Mr Lau said it was difficult for the Government's monitoring team, which would occasionally visit a construction site, to keep a close watch on work. It was also difficult to strengthen monitoring by amending the present Conditions of Sale. A practical way to ensure the quality of flats built under the scheme was for government architects to carry out on-site supervision, he said. There had been allegations that unscrupulous contractors maximised profits by keeping construction costs down. Contractors were tempted to do so because the selling price of the flats was fixed by the Housing Authority and the only way to compensate for the narrow profit margin was by squeezing costs at the expense of building quality. Mr Lau said that contracts awarded under the scheme were mostly dominated by developers which had their own construction arms. The two-in-one relationship made it difficult for architects to do their work. ''Normally, an architect is hired by the developer to monitor the builder's work,'' he said. ''But in a PSPS project, the contractor and developer are usually the same company. ''Then it is very hard for the architect, who is hired by that company, to carry out his monitoring work objectively.'' Mr Lau said the Institute of Architects had submitted its recommendation to the Housing Department. The Housing Authority is conducting a study on ways to plug loopholes in the programme. The scheme has been criticised after complaints about poor building quality. Problems cited by people living in flats built under the scheme are leaks in windows and cracks in ceilings and walls. About 5,000 PSPS flats are provided each year to supplement the Home Ownership Scheme. These flats are produced by private sector developers on land sold to them by the Government.