Investors must be wondering how low yields can fall even in a market where investment opportunities are particularly scarce. A private investor last week settled for a yield of 2.9 per cent for a 790 sq. ft retail unit at the junction of Clyde Road and Morehampton Road in Ballsbridge, Dublin 4. The lock up unit, currently rented at £7,150 but probably worth £10,000, sold at auction for £224,000 and the next review is not due until 2002. The purchaser obviously foresees a redevelopment opportunity but he may have some time to capitalise on the investment as the lease has another 18 years to run. Over two years ago, Lisney also created something of a surprise when it sold the Ulster Bank branch premises in Ballsbridge at a yield of 3.3 per cent.