The present invention relates to a greenhouse arrangement comprising a framework and a system for thermicity improvement. The system for thermicity improvement comprises at least one film. The film is spread over and/or connected directly and/or indirectly to the framework. The film comprises an additive suitable for enhancing the thermicity of the film. Said additive comprises an alkyl phosphonic acid or derivatives thereof. Said film has a transmission of IR of lower than 40% especially lower than 25%.
