The real estate sector is today responsible for 40 per cent of the total amount of energy consumption within the members of the EU. All over the world there are collaborations within research and projects to find ways of reducing the amount of energy consumed by the real estate sector. In Sweden, a directive from the European Union has posed demands on authorities as well as on the private sector to reduce the amount of energy consumed by new building constructions. Together with the directive from the EU there are also new requirements and demands from Boverket for the real estate sector. These requirements mostly concern the energy consumption of kilowatt-hour per square metre and that the consumed energy also should be renewable. The aim of this study is to explain what kind of value municipalities experience in using certifications and environmental investments for new and existing buildings. Within the chapter theory, essential areas are described such as; environmental certification systems, economical viability, proceeds connected to building green, difficulties with building green, the performance of green buildings when affected by the behaviour of tenants and customer value. The following chapter describes the methodology with which we have conducted this study. The method used has had a qualitative approach in the form of interviews. In this chapter there is also a description of the requirements the respondents needed to fulfil, how the interviews have been conducted and the validity of the execution. The empirical chapter presents the material gathered from the interviews. The material has been divided into seven different categories with influence on the respondents. These categories are; economical viability, customer satisfaction index, minimal requirements from BBR, individual measuring of consumption, definitions, environmental certificates and tax relief. In the analysis discussions are held about the results of the interviews in contrast to the theories. Whereas they are in agreement with the theories or stand opposed to them. The conclusion presents a lack of demands from the tenants when it comes to environmental and energy sufficient aspects. This results in a small value added by environmental certificates for the municipalities. To increase the value of green building it is necessary for the tenants to increase the demand of them.