The solar calculator is the best I have come across that gives me the roof area of my roof,who many solar panels that can fit on my roof ,what it will coast me, the amount I will save, electricity that will be generated, what I will be paid from the government feed in tariff FITS cash back schemes . Solar panels should be installed south facing face of the roof that is not shaded.

Agrément Certificates A construction product approval scheme developed by the BBA to provide reassurance to specifiers. BBA HAPAS Product Approval Scheme An approval scheme developed for highway products and systems, run and maintained exclusively by the BBA. Competency Scheme The assessment and monitoring of companies providing U-Value and condensation risk calculations.