This App calculates the SAP, the EI, the TER (target emissions rate), the DER (dwelling emission rate) and the primary energy rating in (KWh/m2/year) of a new or existing dwelling based on simple dwelling dimensions. When designing a new build you need to know if your proposed dwelling meets with regulations before engaging in the drafting of final plans and laying out unnecessary expenses on the EPC certificates etc. Use this App to give you a preliminary examination of all your construction items, windows etc to ascertain if they are up to meeting with the regulations. The App is set up with sample dimensions for a new dwelling for observation of the workings and calculations.