This unit of competency specifies the outcomes required to assess the impact of construction materials, design elements and building condition on thermal performance of residential buildings. It includes selecting appropriate building materials for improving thermal performance, identifying the impact of the construction of key elements of the building envelope on thermal performance, and identifying the correct use and installation of building materials to improve thermal performance.The unit supports the work of Nationwide House Energy Rating Scheme (NatHERS) assessors engaged in assessing the impact of building elements.In some jurisdictions, this unit of competency may form part of the accreditation, licensing, legislative, regulatory or certification requirements for NatHERS assessors.