Fire resistance under the new CPR: the EU just set the performance classes (2026/557)

What was published

Commission Delegated Regulation (EU) 2026/557 of 16 March 2026 was published in the Official Journal on 3 June 2026 and enters into force on the twentieth day after publication (around 23 June 2026). Acting under Article 5(5) of the new Construction Products Regulation (EU) 2024/3110, it determines the classes of performance for the essential characteristic resistance to fire — giving manufacturers a single, harmonised way to declare how a construction element performs in a fire under the new CPR framework.

Resistance to fire is not reaction to fire

The two are easy to confuse. Reaction to fire (classes A1 to F, with smoke s1–s3 and flaming-droplet d0–d2 sub-classes, under EN 13501-1) describes how much a product itself contributes to a fire. Resistance to fire — the subject of 2026/557 — describes how long a building element keeps doing its job once the fire has started, classified under EN 13501-2 with the criteria R (load-bearing capacity), E (integrity) and I (insulation), plus W (radiation), expressed in minutes — for example REI 60 or EI 90.

How resistance to fire is tested

Unlike a small-specimen chemical test, resistance to fire is demonstrated by full-scale furnace testing: a representative element — a wall, door, floor, beam, duct or penetration seal — is built into a furnace and exposed to a standardised heating curve while load-bearing, integrity and temperature criteria are monitored. The general method is EN 1363, with element-specific parts such as EN 1364 (non-loadbearing elements) and EN 1365 (loadbearing elements); the result is then classified under EN 13501-2.

• +EN 1363 — general furnace test conditions and the standard heating curve
• +EN 1364 / EN 1365 — non-loadbearing and loadbearing element methods
• +EN 13501-2 — classification into R, E, I, W and their combinations (e.g. REI 60)
• +Extended application (EXAP) reports — cover product variants without re-firing each one

Why there is no flat price for this one

LCAS publishes indicative figures where a test has a definable base rate. Resistance-to-fire testing is the honest exception: the cost depends on the specific element — its size, construction, loading and how many configurations need a furnace run — and large assemblies occupy a furnace for a full day. Rather than quote a misleading single number, the practical step is to scope the element and the number of configurations first. Extended-application reports are often the lever that keeps the programme affordable, by avoiding a separate firing for every variant.