RATES for residential properties are expected to increase by as much as 40 per cent next year because of the residential boom in recent years. Lyall Alexander-Webber, director of the valuation department at Vigers Hong Kong, said the increases would be in line with the average rental growth for residential properties. The rate increase for luxury housing properties could be 50 or 60 per cent, he said. Rates for retail shops would also rise quite significantly, while there would be marginal increases for office properties, he said. The new rates, likely to take effect in April, are expected to fuel the need for professional advice for property owners on whether and how to object to the new rating assessment. Vigers and Deacons have joined forces to offer a legal and valuation rating advice for property owners. Mr Alexander-Webber said the service could help property owners save millions of dollars by lodging appeals on the Government's new rating assessment. ''Ratepayers have a legal right to object to the new rating assessment, and those who seek professional advice early will be in the enviable position of receiving a quick response when the rating assessment is made,'' he said. Not many appeals are expected from individual homeowners, and most appellants are expected to be large corporations with specialised properties such as club premises, oil terminals and container terminals. Deacons' partner Peter Wintle said: ''Normally it is not until a breakdown in negotiations has occurred that the lawyers become involved, so we decided to assemble a team of professionals who are known to each other and can work together right from the very beginning in a systematic approach in order to avoid the pitfalls and to minimise the expense.'' Colin Sharp, an associate with Vigers' British affiliate Grimley J.R. Eve, said it had successfully argued rating cases in Hong Kong and expected the same success in the new partnership.