THE Government is too casual in designating land as a Comprehensive Development Area (CDA), which can freeze land use and block development, the new president of the Hongkong Institute of Architects said yesterday. Mr Dennis Lau Wing-kwong said the Planning Department seemed to be designating land as a CDA more often than in the past and the development of certain areas had been obstructed. Mr Lau, who took up the presidency this month, said there were about 80 CDAs in the territory and land use had been frozen for no good reason. He said it was understandable that the designation was applied to environmentally sensitive areas such as the Peak, the waterfront and districts without adequate infrastructural services. This allowed proposed developments to be considered in the light of design merit and ability to cope with an area's constraints. ''But such a planning tool is too widely used and almost all development sites of a sizeable area have been designated even before the drafting of the outline zoning plans for these sites,'' Mr Lau said. Without outline zoning plans, the blueprints for various types of land use, developers and owners would not know what purpose the Government had in mind for those areas. The Government refused to talk to individual land owners unless small owners formed a conglomerate. Mr Lau urged the Government to confine the CDA designation to certain locations and said outline zoning plans should be announced as soon as possible. But the Director of Planning, Mr Peter Pun Kwong-shing, said there were only about 50 CDAs in the territory. Most of these sites had been developed according to the Government's plans. Mr Pun said the department would consider the development potential of a particular site in the light of the environmental impact of a development on the surrounding area. Opinions from other relevant government departments would also be sought before making a recommendation to the Town Planning Board for endorsement. Mr Pun said the Government did not spell out the land use for CDAs because this provided flexibility. ''If the Government stipulates specific land uses for the CDAs, then we may be criticised for being too rigid,'' he said. The owners of smaller sites within a CDA could proceed with their own development plans as long as their plans were compatible with the comprehensive development of the area. If these development plans were incompatible with the comprehensive development plan, Mr Pun said the owners could suggest ways to alter the comprehensive plan. But he could not recall any cases in which small owners had managed to submit counter proposals and to have their proposals accepted by the Government.