A £3.75m deal to buy an empty office on Water Street in Liverpool has been completed, with plans afoot to convert its upper floors into 96 apartments.The 73,000 sq ft office at 8 Water Street was purchased by a partnership between long term business associates Craig Blackwell of Prospect Capital and Martin Wilcocks of Wilcocks & Wilcocks.Plans for the 1970s building include a complete overhaul of its façade, the installation of feature lighting throughout and, subject to planning, an addition of two further floors and roof terrace.The project will bring the gross development value to £14m.