The European standard that takes life-cycle assessment from product scale to building scale: it defines the calculation method for quantifying and reporting the environmental performance of a construction, new or existing. It is the counterpart of EN 15804, which governs product EPDs: one supplies the data, the other says how to add it up. A protected technical standard: its logic is described, not reproduced. The current edition is EN 15978:2026, which superseded EN 15978:2011.
It applies to assessing the environmental performance of new and existing buildings and of renovation works. It is voluntary as a standard, but it is the method referred to — directly or in practice — by the instruments that require a building's footprint to be calculated: the Minimum Environmental Criteria in public procurement, the EU Taxonomy for sustainable finance, and the EPBD directive, which introduces the calculation of life-cycle global warming potential for new buildings.
It applies the life-cycle assessment framework of ISO 14040 and 14044 at building scale. It structures the assessment by life-cycle stages — from material production to construction, use and end of life, plus benefits and loads beyond the system boundary — and defines the object of assessment, the system boundaries, the reference period and the rules by which product data are aggregated. The input data are largely those of EPDs drawn up to EN 15804. Here we describe its framework: indicators, formulas and detailed rules remain protected content of the standard and must be read in the original.
The scale. EN 15804 sets the rules for Environmental Product Declarations: it says how the footprint of a material or component is measured. EN 15978 says how those footprints combine into that of a whole building, accounting for installed quantities, service life, replacements and end of life. They are two links in the same chain: without the first the data are missing, without the second there is no way to add them up.
No, and that is why this standard exists. A set of virtuous products does not automatically make a virtuous building: what counts is the quantities actually used, the service life of each element and how many times it will be replaced, the energy consumed in operation, and what happens at end of life. A material with an excellent EPD used in excess, or destined to be replaced three times, can weigh more than a worse one used well.
As a technical standard it is voluntary. It becomes necessary in practice, however, whenever a binding instrument requires a building's footprint to be calculated: the Minimum Environmental Criteria in public procurement, the EU Taxonomy, and the EPBD directive, which introduces the calculation of life-cycle global warming potential for new buildings. The voluntariness concerns the standard, not the obligation that invokes it.
Because it is a technical standard under protected reproduction. Architheca's editorial rule is clear: for UNI, EN and ISO standards we describe the logic — what they are for, how they are built, how they connect to the others — but we do not reproduce tables, values or clauses, and we do not link to those who sell them. For specific content, consult the standard at the standardisation body.