What life cycle assessment covers
Operational energy captures what a building consumes in use. Life cycle assessment additionally captures what its construction, maintenance and demolition cause.
| Phase | Subject |
|---|---|
| Production | raw material extraction, transport, manufacture of products |
| Construction | transport to site and installation |
| Use | operation, maintenance, replacement of elements |
| End of life | demolition, transport, recovery or disposal |
The share of production grows as operation improves. In a building with very low operational demand, the weight shifts to the emissions embodied in materials. That is the substantive reason the quantity is being added.
How it is being anchored in law
The European buildings directive introduces a duty to determine greenhouse gas emissions across the life cycle and to set them out in a report. The national anchoring is still outstanding.
Three elements of that anchoring are foreseeable. They concern the certificate, the timetable and the limit values.
| Element | Content |
|---|---|
| The assessment becomes part of the energy performance certificate | which is itself being digitised and extended |
| The duty applies in stages | first to larger new buildings, then more widely |
| Limit values are to follow | the national building renovation plan is eventually to provide binding limits |
The national implementing act was promulgated on 28 July 2026. The provisions transposing the directive, including the life cycle reporting duty, are nonetheless expected in the professional literature to take effect in early 2027. The precise thresholds, accounting rules and limit values were not fixed at the date of checking. The article on the Building Modernisation Act covers the position.
Why it must begin early
This is the point the professional bodies have particularly stressed in the debate on transposition. It concerns when in the design sequence the assessment is made.
A life cycle assessment must not be understood as a downstream calculation at the end of a project. The decisions that shape it are taken early: structural concept, material choice, compactness, treatment of existing fabric.
Prepared only after detailed design, it documents a result instead of influencing one. The effort arises; the benefit does not.
An open question follows for the service profiles: whether the assessment becomes a basic service or remains an additional service is part of the ongoing debate on the fee ordinance. The article on additional services covers the boundary.
The link with building in existing stock
One consequence follows almost inevitably and changes how refurbishment projects are assessed. It concerns the relation between retention and replacement.
A retained element causes no production emissions. Where the assessment captures production, retaining existing fabric gains weight against replacement, including where replacement would be better in operational terms.
That applies particularly to structure and shell, whose emissions share is high and whose service life far exceeds that of other elements. Both are typically retained in a refurbishment.
For cost work in existing buildings it means retention and replacement must in future be compared not only on cost and operational energy but also on embodied emissions. The assessment becomes a third quantity alongside both.
What follows for cost work
Three relationships are foreseeable.
| Relationship | What follows |
|---|---|
| The assessment needs the same data as the cost calculation | quantities, elements and materials are required for both |
| Reference quantities must be settled | an emissions figure per square metre presupposes the same definition of reference area as a cost benchmark |
| Costs in use are added | the life cycle view connects with the view of costs in use |
Related articles
This article reflects the position of the legislation at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.