This report presents the results of a heritage assessment and a heritage impact assessment that was carried out by South West Archaeology Ltd. (SWARCH) for a residential development at Land at Pentewan Road, Trewhiddle, St Austell, Cornwall. The proposed site is located on the southern edge of St Austell and to the west of the A390. In terms of indirect impacts, most of the designated heritage assets within the wider area are located at a distance whereby the impact of the proposed development on the assets would be minimised, or where the contribution of the setting to the overall significance of the assets is less important than other factors. The landscape context of many of the assets is such that they would be partially or wholly insulated from the effects of the proposed development by a combination of local blocking from trees, buildings, or embankments, or from modern intrusions that have already impinged upon their setting. The only asset where any appreciable impact would be noted is the Grade II Listed White House/Cornwall Hotel (Negative/Minor). Trewhiddle Farmhouse is not Listed, however it is of equivalent value to the Grade II Listed White House/Cornwall Hotel and it is here that the most pronounced impact would be felt (Negative/Moderate). With this in mind, the overall impact of the proposed development can be assessed as negligible to negative/minor. The impact of the proposed development on any buried archaeological resource would be permanent and irreversible, however this could be mitigated through an appropriate programme of archaeological monitoring and recording.