The construction sector has a big impact on the environment, and a BREEAM (Building Research Establishment´s Environmental Assessment Method) certification is one way to reduce its impact. BREEAM is a well-known international certification method for buildings. The certification is a measure of the building´s sustainable qualities and consists of the ten different categories Management, Health and wellbeing, Energy, Transport, Water, Materials, Waste, Land use and ecology, Pollution and Innovation. Points are obtained in the different categories, and a total score is calculated. The total score corresponds to a classification in BREEAM.No residential building in Norway has been BREEAM certificated so far due to the lack of facilitating. Norgeshus has a residential concept called Dråpen which will be used in this BREEAM certification. The goal is to find out whether a certification is favourable, and which classification is the better choice. Furthermore, it will be interesting to see the effect that the customer and lot have on the certification. In this thesis a comparison of Dråpen planned after TEK17 and BREEAM classification Good has been done to see the differences. Due to changes and upgrades, the house planned after BREEAM-NOR will be more expensive. The optimal classification for a residential is Good according to the results in this thesis. A generalization will be difficult to achieve since the building lot has a bigger impact than first assumed. Considering a lot with a central location will give some extra points without doing modifications on the building or in the planning process. Calculations of costs for TEK17 and BREEAM has been compared. To achieve a BREEAM-NOR certification with character Good, the total price difference is estimated to about 455 000 kr. The price mainly includes extra management and documentation, different materials and costs for registration, certificate and BREEAM-NOR-AP. For the calculation the program SmartKalk has been used. Unfortunately, the price for registration and the certificate in Norway is not suitable for a single residence. Prices are intended for bigger concepts, like apartment buildings, and need to be adjusted for residential buildings. In Spain and The Netherlands they have own prices for residential buildings, therefore a BREEAM-certification of residential building is a great alternative to regular building methods.