Table 1 Causes of energy performance gaps in buildings (Jradi et al., 2018)
Design Phase | Construction Phase | Operation Phase |
|---|---|---|
- building energy modeling limitations and uncertainties - oversimplified inputs regarding the built quality and fabric performance - design complexity - performance targets miscommunication - unrealistic early design decisions - lack of integrated design principles considering energy consumption and indoor thermal comfort and air quality - failure to predict functional and stochastic changes - components and systems over-sizing and under-sizing - lack of energy modeling and simulation knowledge and skills - uncertainties and generic assumptions in weather conditions, occupancy patterns and behavior, heat gains and plug loads | - mismatch between the quality at the building handover and the quality at the design stage - changing requests from clients - poor commissioning - improper envelope assembly - economically driven decisions affecting materials and systems selection leading to design modifications - improper components and systems integration | - lack of continuous commissioning - mismatch between design idealized assumptions and actual patterns - faulty systems and components - poor practice - lack of maintenance and service - occupants’ behavior and activities - lack of occupancy monitoring - variation in systems operation modes and changes in the use of the building - inappropriate building management and control strategies - faulty sensors and meters - lack of customers and residents’ knowledge in terms of energy efficiency and building operation |