EN 13164 Explained: The XPS Insulation Standard

3 September 2026

EN 13164:2012+A1:2015 is the harmonised European standard that defines the requirements, test methods, classification system and marking rules for factory-made extruded polystyrene (XPS) thermal insulation boards used in construction. It enables manufacturers to draw up a Declaration of Performance (DoP) and apply the CE mark, and gives specifiers a consistent, comparable basis for product selection across all EU/EEA markets. All PNP XPS boards are manufactured and tested in conformity with EN 13164:2012+A1:2015.

What EN 13164 Is and Why It Exists

EN 13164:2012+A1:2015 is the harmonised European product standard for factory-made extruded polystyrene (XPS) thermal insulation boards intended for use in buildings and civil engineering structures. It is published by the European Committee for Standardisation (CEN) and adopted without change by national standards bodies in all EU and EEA member states.

Under Regulation (EU) No 305/2011 (the Construction Products Regulation, CPR), a harmonised standard creates the legal framework for CE marking. A manufacturer who demonstrates conformity with EN 13164 can draw up a Declaration of Performance (DoP), apply the CE mark, and place the product on the European single market. All PNP XPS boards produced at the Várpalota plant (Hungary) are manufactured and tested in conformity with EN 13164:2012+A1:2015.

What the Standard Covers

EN 13164 defines:

Material scope — rigid boards made by the extrusion of polystyrene (XPS), with or without facings or coatings.
Dimensional characteristics — length, width, thickness, squareness and edge profile requirements, and the tolerance classes (e.g. T1) used to classify them.
Thermal performance — the method for declaring the thermal conductivity (λD, W/(m·K)) and the derived thermal resistance (RD, m²·K/W).
Mechanical properties — compressive strength at 10 % deformation or yield (CS(10\Y), in kPa per EN 826), tensile strength perpendicular to faces (TR), compressive creep (CC(2/1,5/50)), and deformation under load at temperature (DLT(2)5).
Hygric properties — long-term water absorption by total immersion (WL(T)) and by diffusion (WD(V)).
Durability indicators — dimensional stability at elevated temperature and humidity (DS(70,90)) and freeze–thaw resistance after diffusion (FTCD).
Reaction to fire — Euroclass classification (e.g. E or F) per EN 13501-1.
Marking and labelling — the mandatory information that must appear on every product or its packaging to enable traceability and compliance verification.

The Classification System: How to Read an XPS Product Code

EN 13164 uses a structured designation system that encodes the key declared values. The table below maps the notation used on PNP XPS data sheets and DoPs to the underlying standard concept.

Notation	Property	Example value (XPS 300)
CS(10\Y)300	Compressive strength at 10 % deformation or yield (EN 826)	≥ 300 kPa
λD	Declared thermal conductivity	0.034 W/(m·K) (20–100 mm)
WL(T)0,7	Long-term water absorption by total immersion	≤ 0.7 Vol.-%
WD(V)3	Long-term water absorption by diffusion	≤ 3.0 Vol.-%
DS(70,90)	Dimensional stability at 70 °C / 90 % RH	Declared
FTCD1	Freeze–thaw resistance (after diffusion)	≤ 1 Vol.-%
CC(2/1,5/50)130	Compressive creep: 2 % creep strain, 1.5 % initial deformation, 50 years, 130 kPa	130 kPa
TR 400	Tensile strength perpendicular to faces	≥ 400 kPa
T1	Thickness tolerance class	T1
E / F	Euroclass reaction to fire	E (XPS 300); F (XPS 150)

Each PNP XPS DoP lists the declared value for every property that is relevant to the intended use. Specifiers should always check the current DoP and TDS for the specific product and thickness being considered.

How EN 13164 Affects Product Selection

Because EN 13164 requires that every declared value is substantiated by testing and factory production control, specifiers can compare products from different manufacturers on an equal footing — provided they read the declared class, not just the grade name.

Key points for practical specification:

Compressive strength class is the primary selection criterion for load-bearing applications (foundations, floors, roofs under traffic). CS(10\Y)150, 200, 300, 400, 500 and 700 are the classes offered by PNP XPS.
Surface type (smooth, waffled W, or milled-and-grooved MG) is not a property classified by EN 13164 itself, but it affects suitability for bonded systems (ETICS, renders, tile adhesives) and is declared in the DoP under intended use.
Water absorption class matters for below-ground, inverted-roof and road applications. A board declared WL(T)0,7 (≤ 0.7 Vol.-%) provides substantially better moisture resistance than one declared WL(T)3.
Fire class is a national building-regulation input. PNP XPS 300, 400, 500 and 700 are classified E; PNP XPS 150 and 200 variants are classified F. Whether class E or F is acceptable in a given application depends on the applicable national fire regulation — consult a qualified fire engineer and the relevant national code.

For a structured guide to choosing between PNP XPS grades, see Which PNP XPS Should I Choose? Application Guide.

EN 13164 and the Declaration of Performance (DoP)

Every PNP XPS product is accompanied by a DoP drawn up under Regulation (EU) No 305/2011. The DoP references EN 13164:2012+A1:2015 as the harmonised technical specification, identifies the product type, lists the declared performance values for each essential characteristic, and bears a unique identification number for traceability.

DoPs for all current PNP XPS products are available from the Documentation section of this website. BIM objects that embed the declared performance data are available via PNP BIM Libraries. An Environmental Product Declaration (EPD) covering the Várpalota plant, prepared in accordance with EN 15804, is also available in the same section.

Where a specific declared value is not shown on this page, refer to the current TDS and DoP for the product in question, or contact PNP XPS directly.

Sources

EN 13164:2012+A1:2015 — Factory-made thermal insulation products for buildings — Specification for extruded polystyrene foam (XPS) products
Regulation (EU) No 305/2011 (Construction Products Regulation, CPR)
DoP PNP XPS 300 EMI_en (U).pdf (updated 2025-10-14)
DoP PNP XPS 300 W EMI_en (U).pdf (updated 2025-10-13)
DoP PNP XPS 500_en (U).pdf (updated 2025-07-22)
DoP PNP XPS 700_eng.pdf (updated 2025-03-17)
DoP PNP XPS X-Grip_en (U).pdf (updated 2026-06-24)
DoP PNP 300 SLOPE A1-B1_en.pdf / A2-B2_en.pdf (updated 2025-03-17)
TDS pnp_xps300-300TB_600x1250_techcard_en (updated 2026-07-22)
EPD — PNP XPS (Várpalota plant), updated 2025-03-19
PNP BIM Libraries, updated 2025-02-24

Frequently asked questions

Is EN 13164 mandatory for XPS boards sold in the EU?

Yes. EN 13164:2012+A1:2015 is a harmonised standard under Regulation (EU) No 305/2011 (CPR). Any XPS board placed on the EU market for use in construction must be CE-marked and accompanied by a Declaration of Performance that references this standard. All PNP XPS boards comply with EN 13164:2012+A1:2015.

What does CS(10\Y)300 mean on an XPS data sheet?

CS(10\Y)300 is the EN 13164 compressive strength class: the board achieves a compressive stress of at least 300 kPa at 10 % deformation or at the yield point (whichever comes first), tested in accordance with EN 826. For a fuller explanation, see the knowledge article <a href="/knowledge/300-kpa-meaning/">What Does '300 kPa' Compressive Strength Mean?</a>.

Does EN 13164 classify reaction to fire?

EN 13164 requires that reaction to fire be declared using the Euroclass system of EN 13501-1, but the classification itself is determined by separate fire tests referenced in the DoP. PNP XPS 300, 400, 500 and 700 boards are classified Euroclass E; XPS 150 and XPS 200 variants are classified Euroclass F. Whether a particular class is acceptable depends on national building regulations — this requires assessment by a qualified designer.

What is the difference between WL(T) and WD(V) in EN 13164?

WL(T) is the long-term water absorption measured by total immersion (the board is submerged), expressed as Vol.-%; it is the key indicator for below-ground and inverted-roof applications. WD(V) is the long-term water absorption by diffusion (vapour-driven), also in Vol.-%; it is relevant for assessing freeze–thaw resistance and is used together with the FTCD test. Both are declared in the DoP for each PNP XPS product — see the current TDS for product-specific values.

Can I use the EN 13164 declared λD value directly in a U-value calculation?

The declared thermal conductivity λD is the starting point, but national annexes and building regulations in different countries may require additional correction factors (e.g. for moisture, fixings or installation conditions) before the design thermal conductivity λdesign can be used in a U-value calculation. A qualified building physicist or structural engineer should confirm the applicable national methodology — see the current TDS for the declared λD values for each PNP XPS product and thickness.

Where can I download the DoPs and TDS documents for PNP XPS products?

All current Declarations of Performance and technical data sheets are available in the <a href="/documentation/">Documentation</a> section of the PNP XPS website. BIM library objects are also available there. For any document not listed online, contact the team at sales@pnpinsulation.com.