Method combining expert and analytical approaches towards economical energy renovation roadmaps and improved indoor comfort

This paper proposes a two-fold method, combining expert and analytical approaches, to develop an energy renovation roadmap for residential apartment buildings. The expert approach provides cost estimates based on energy performance certificates, considering the building's existing condition, national building tradition, and requirements. Renovation actions are limited to the most probable and required actions. The analytical approach uses computer power and various renovation action variations to identify optimal solutions for defined KPIs. As the cost efficiency of energy conservation action depends on model complexity, the expert approach considers this aspect. The analytical approach focuses on indoor comfort and energy use, as cost optimality evaluation is not possible for non-linear costs of energy conservation actions. Sensitivity analysis is used to support credible ranges for rentability of energy conservation measures and reflect on optimal solutions and indoor environmental consequences.