Recent studies depict the general need to increase and improve innovation in the construction industry. Innovation processes are traditionally described and analysed either on a macro level or a micro level. Production in construction is basically project oriented, as opposed to manufacturing industries for which most of these theories are developed. It is not fully sufficient to study innovation from a micro or a macro level due to the effects of the project orientation and the large number of actors in the construction industry. The objective of this paper is to present a model of the construction innovation systems from a sector systems approach. The study rests upon findings in the area of innovation systems in general and construction innovation systems in particular on one hand and construction sector systems analysis on the other. This paper presents arguments for the development of activity based innovation systems at a construction sector level.