 Rebuilding work did not begin in earnest until 1863 , when William Gibbs had the property substantially remodelled in a Gothic Revival style . William Cubitt & Co. were the builders and John Norton was the architect . Norton 's design enveloped the original house . He added an extra floor , two new wings and towers . Norton emphasised the importance of architectural continuity in restoration and rebuilding relating to several historical periods . As a result , while some walls remained plain , others were adorned with Gothic and naturalistic carvings to fit in with the previous architectural styles . 
