75 Harley Street is made up of two Grade II listed buildings, 73 and 75. Chalfont This address consists of 18 individual suites and Chalfont Electrical Services completed a full electrical installation to this site including overseeing the installation of UKPN substation, provision of HV control equipment, private transformer, 800a Ryefield and individual metering requirements for 18 suites. Access control for the whole building with door entry for porter management.