Strategic and systematic integration of solar thermal in the building sector can lead to energy security and emission reduction. The impact of such renewable energy application could be boosted when an integration scheme is formulated by considering the changing meteorological conditions and periodic variabilities in the profile of heat demand. The efficiency of such networks could be enhanced by incorporating heat storage technology and backup utility system to form an integrated design. In this paper, a new approach based on multi-period Mixed-Integer Non-Linear Programming (MINLP) which captures such features is developed for integrating solar thermal with the space heat and hot water supply network of a cluster of buildings. The integration scheme is implemented and solved in GAMS and considers the hourly changes in solar irradiation and ambient temperatures, together with the effects of these changes on integration variables across different time horizons. Two scenarios are considered, the first involves four winter months while the second entails four summer months. The results obtained show that solar thermal satisfies 7.4 % of the total heat required in the winter months, while it fully supplies the total heat demand in the winter months.