Use of adaptable solutions to achieve near-zero energy buildings through a combined thermal and comfort performance approach

The existing residential building stock in many industrialized countries is large but extremely energy inefficient, despite the existence of energy directives that apply mostly to new construction. Prefabricated building refurbishment for energy upgrading is a viable option for the existing building stock, but solutions need to adapt to each case and usage in order to respond to specific requirements. The “RECO₂ST” project (Horizon 2020) is used as example of a forecast methodology that can help achieve nearly zero energy refurbishments, through selection of innovative modular elements for the opaque and transparent areas of the building envelope, covering diverse energy reduction strategies while improving thermal comfort and indoor air quality. This integrated approach is not usual in the field. The Technical Note studies a series of facade and active window technologies that supply climate strategies such as insulation, heat recovery and ventilation. The methodology is demonstrated for three sample cases using a typical refurbishment scenario. It is evaluated through energy simulation and analysis of improvements in thermal comfort and indoor air quality indicators.

Practical application: The methodology helps to reduce guesswork for actions to be taken in order to refurbish and upgrade the existing housing stock to comply with current energy directives. It takes into account at the same time energy performance and user comfort, as expressed through indoor air quality.