Delivering boutique housing developments in south Dublin’s leafier suburbs has been a hallmark of property developer Seabren. “Gold taps, lifts and a cinema in Rathgar”, snapped one headline as Highfield, a pair of six-bedroom houses, hit the very top end of the market in late 2020, with an asking price of €3.25 million apiece.  Building in prime locations has meant Seabren has specialised in mid to high-end infill developments that nestle among period red bricks in areas like Ranelagh, Terenure, Kimmage and Portobello. A lucrative game in a fevered housing market, you might assume. Especially as Seabren paid an estimated…