Complex sentence: Also within the grounds were two office buildings built in the 1980s and these housed other companies such as mobile data solution provider CognitoIQ, Exony and Idox, all of which have now moved to other premises as the phases comprising the office block were demolished.
Split into simpler sentences: Also within the grounds were 2 office building built in the 1980's and these housed other companies such as CognitoIQ a mobile data solution provider, Exony and Idox. All of which have now moved to other premises as the phases comprising the office block were demolished.