The report presents an investigation of whether it is possible to use certification systems in renovation of existing city districts. The study was a part of the larger project Sustainability Certification of Neighborhoods (HCS) with funding from the Delegation for Sustainable Cities. The basis has been to gather the views of professionals, researchers and students working with remodeling processes in various municipalities in Sweden. There is a great interest for a systematic approach that takes into account, social, economic and environmental aspects. There are established methods today but usually a holistic approach for sustainability is missing. Knowledge about the remodeling process and sustainability issues may also vary between different municipalities according to size, resources and expertise. The million program housing areas with large potential for improvement but limited financial resources are particularly challenging. A certification system could be a way to create a framework with a common vision and ambition for all parties involved. General requirements for Swedish conditions have been developed for certification systems for city districts, consisting of four core values: tomake a difference, to be useful, to be credible and to be adaptable . BREEAM Communities 2012 has been reviewed according to these general requirements and from the view of professionals working with remodeling of existing city districts. The system today is developed for new construction and therefore needs a thorough adaptation to conditions in existing city districts. The system was found to be relevant and many of the aspects that are currently in the system are important. However, the logical structure must be reviewed and modified to fit the rebuilding process. The category Governance was found to require most changes due to the variety of actors with different decision-making phases and the fact that the basis is existing buildings and infrastructure. A Swedish system should also be less detail-regulated to safeguard a system perspective especially in terms of water, energy and waste. The socio-economic aspects are deemed to be more important for certain areas and it is therefore requested that different sustainability aspects may need to be given different weight depending on opportunities and challenges in a specific city district. To document the benefits of a certification process is very important. Therefore a follow-up mechanism should be included that measures the status before and after the renovation of the city district and thus provide a basis for evaluating the benefit. A first set of indicators have been identified for the various categories of BREEAM Communities. These need to be developed further with clear references to research and practice in order to gain credibility for a system. Due to the large number of actors that may need to be involved in the remodeling area it can be difficult to create common organization and economic resources for the certification process. Three different approaches for financing were discussed; the establishment of a fund in which all actors contribute, divide the area into smaller sub-phases with less number of players and faster implementation, or assume a financial investigation that shows who gets the greatest benefit from the certification so that they can account for most of the certification and investigation costs. This report is only available in Swedish.