Ratio Seven are fully accredited SAP assessors and authorised airtightness testers with over 20 years of house building experience. Offering residential & commercial air testing and SAP calculations, energy consultancy services for housing developers, associations and architects. Keywords: air testing, airtightness testing, sap calculations, air permeability testing, commercial air testing, residential air testing Business Hours: Monday – Friday: 09:00 – 17:00 Business Since: 2008