Gascoignes Chartered Surveyors are commercial property agents who cover London, Surrey, Berkshire, Hampshire, & Sussex. As commercial agents regulated by the royal institution of chartered surveyors we specialise in commercial property, Property investments, commercial property valuations, and property management.. Gascoignes Chartered Surveyors are commercial property agents who cover London, Surrey, Berkshire, Hampshire, & Sussex. As commercial agents regulated by the royal institution of chartered surveyors we specialise in commercial property, Property investments, commercial property valuations, and property management.