Official Definition of Zero-Emissions Building

Terminology Overload

Your head would be in a spin with terminology overload on opinions and definitions of building performance levels such as “net-zero”, “zero-energy”, “zero-carbon” and so forth. So, we thought we’d cut to the chase and consult with the EU Directive on the Energy performance of Buildings (EPBD) to see what its take is. After all, the EPBD is the driving force behind energy performance legislation across the entire EU.

The EPBD is bringing in three-legged legislation which is going to require a step change in building performance in terms of (1) efficiency, (2) life-cycle emissions and (3) ‘beyond energy’.

Official EU Definition

So, the EU wide definition refers to “zero-emission buildings” and defines those as “buildings with a very high energy performance in line with the energy efficiency first principle, where the very low amount of energy still required is fully covered by energy from renewable sources at the building or district or community level”. Note the term “fully covered” as it relates to renewable energy. The current legislation specifies that a “significant” proportion of energy should be covered by renewables. For zero-emissions buildings, we’re going to see a shift from ‘significant proportion’ to ‘fully covered’.


Solar panels on a net zero zero emissions building ireland

Efficiency-First to Minimise Renewable Requirement

The most economic way to fully cover a building’s energy requirement with renewable energy is to ensure that the buildings energy demand is minimised. Put simply, an inefficient building would need an extensive renewable energy system, whereas a hyper-efficient building would need much less. Readers will note the “efficiency first principle” is front and centre in the legislation, requiring excellent building fabic, optimised solar gains and efficient mechanical systems. This all sounds very much like the Passive House approach, right?


Whole Life-Cycle Emissions

So far we’ve only touched on what might be regarded as the ‘operational energy’ of buildings, or the energy required to ‘operate’ the heating, cooling, hot water, ventilation, lighting and plug loads. There’s a wave of legislation coming soon which will require building designers to also consider the ‘embodied energy’ of buildings. The EPBD refers to this as “whole life-cycle greenhouse gas emissions”, meaning “the combined greenhouse gas emissions associated with the building at all stages of its life-cycle, from the ‘cradle’ (the extraction of the raw materials that are used in the construction of the building) over the material production and processing, and the building’s operation stage, to the ‘grave’ (the deconstruction of the building and reuse, recycling, other recovery and disposal of its materials)”.

Considering whole life-cycle emissions is going to bring into sharp focus to the materials that we use in our buildings. Products with high life-cycle emissions are going to adversely affect a building’s rating, and vice versa. Designers and specifiers, lets be honest, have, in the main, been ignoring embodied energy to date. That’s all about to change folks.

Beyond Energy Performance

Having considered both fully-covered operational energy as well as life-cycle emissions, the third leg of the EPBD legislation will require new buildings to go “beyond energy performance”, to address such matters as “healthy indoor climate conditions, adaptation to climate change, fire safety, risks related to intense seismic activity and accessibility for persons with disabilities”. “Proper-order” I hear you say.

Adapting to climate change in particular is likely to present the greatest challenge to designers and specifiers. Our winters might be getting milder, but summers are getting hotter which will require us to focus providing year-round comfort and minimise summer overheating risk.

When does all this kick-in?

The above three requirements need to be implemented for public buildings and buildings greater than 2,000m2 by 1st January 2027 and by the 1st January 2030 for all other buildings. Those dates are going to come around very quickly, so it’s time to get our skates on and gear up to deliver to the impending EPBD legislation.

At NetZeroBAU, our mission is to help you prepare for these changes so that you can best serve the needs of your Clients.

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