Words from the wise, read these contributions to the discussion from our experts

The REHVA Journal, expertly edited by our expert Jaap Hogeling, is a tremendous platform for delivering expert information about the energy transition and the energy performance of buildings. Here are 3 articles which our experts co-authored from the April 2022 issue.

A common European EPB Assessment and Certification scheme. U-CERT’s proposal
Buildings are responsible for great share of the global GHG emissions. Increasing buildings’ energy efficiency is crucial to decarbonise the EU.

For energy performance policies and requirements to have actual impact on buildings’ direct and indirect emissions is crucial to develop robust, accurate, meaningful and user-friendly assessments and certification schemes.

This paper presents a methodology .to calculate building energy performance fully compliant with EPB Standards. Also, it proposes a selection of holistic indicators aiming to overcome shortcomings of national energy performance certificates, while being compliant with the latest version of the Energy Performance in Buildings Directive (EPBD).

The results have the ambition of laying the foundation for a common European EPB assessment and certification scheme.

How to set primary energy requirements so that poor building envelope cannot be compensated with extensive PV?
Ongoing EPBD revision has brought up a question how the definition of zero-emission buildings (ZEB) should be established so that it will support the application of energy efficiency measures hand in hand with renewable energy measures and would avoid possible misuses based on compensation due to renewable energy production on-site when included in the annual balance calculation.

More specifically the issue is related to on-site photovoltaic (PV) generation. In the winter there is no or very limited PV generation and buildings have to use grid electricity that will cause CO₂ emissions. These grid CO₂ emissions happen in the different time, the heating season, where sufficient PV generation is not available.

Even in cases with very extensive PV installations and export in the summer buildings cannot benefit from this without seasonal electricity storage. On a shorter time scale, hourly variations during the day, similar effects occur.

The EPBD recast: how to come to a transparent and fair ZEB definition
In the discussions on the definition and metrics for zero-emission buildings in the ongoing EPBD revision, several aspects have been covered in recent articles.

In this article a new and simple metric is proposed that can be used for threshold values for “the very low energy demand” that is to be “fully covered by energy from renewable sources”. It can be used to safeguard a highly energy efficient building and, in combination with the main overall energy performance indicator, to set out trajectories towards a true zero-emission building (ZEB).

Keywords: EPBD recast, zero-emission buildings, threshold values, energy performance indicator, hourly energy performance calculations.