Our thermal calculator will determine the performance of a single element which could be a wall, floor or roof. The lower the U Value calculation (W/m²K) determined provides a higher level of thermal performance. With the Building regulations Approved document L a minimum elemental performance will be required. You may need to consider improving the thermal performance of an element to compensate within your design (i.e. choice of windows, heating system etc). To determine the overall performance of a building the calculation provided will be added into SAP calculation software (domestic buildings) or alternatively SBEM calculation (commercial buildings).