Lundhagem was commissioned by Mustad Eiendom to develop the master plan and detailed regulation for Mustad Nord. The work included participation in the preparation of the impact assessment, as well as an application for a change of zoning for two of the housing estates.The detailed regulation facilitates further development and densification of Lilleaker with housing and a variety of functions.

The plan relates to the scale of the surrounding historical buildings, as well as the adjacent CC Vest shopping center and Lysaker, while simultaneously maintaining the open, green qualities that characterize Lilleaker. As a result of the area's complex transport facilities, nature and cultural values, an impact assessment was prepared. The plan was adopted in 2011, with construction starting in 2017 and the final stage completed in 2023.The plans involve two separate residential areas. Lilleaker Vest comprises seven residential buildings with facilities, consisting of detached high-rise buildings of eight to ten stories, with a total of 208 apartments. Schlägergården Hage consists of 69 apartments spread over four residential buildings of five to eight floors.

During the development, Lundhagem has worked closely with the Cultural Heritage Management and the Urban Environment Agency (Bymiljøetaten). Of particular importance has been the consideration of the surrounding historic buildings and the restoration of nature, including preservation of existing vegetation and re-establishment of the historic garden connected with Fåbro gård and the apple orchard.