 Although most of his designs were in Neoclassical style , he also created buildings in Gothic style , for example at Lancaster Castle , and Hardwick Grange . Nevertheless , he is considered to be one of the main influences in the Greek Revival of architecture in the late 18th and early 19th centuries . The architectural historian Giles Worsley describes him as " the first English architect to grasp the full potential of the Greek Revival " , and David Watkin says he is the " finest " of the architects who revived the forms of Greek architecture . Of the Shire Hall in Chester Castle , Worsley says it is " the first serious monument of the Greek Revival " . Writing about Harrison 's designs at Chester Castle , Pevsner says " What he [ Harrison ] has achieved here is one of the most powerful monuments of the Greek Revival in the whole of England " . 
