Europe Finally Has a Sauna Standard. The Nordics Aren't Sold.

Europe just got its first common rulebook for public saunas. EN 18164:2026, approved by CEN on January 26, 2026 and issued as a European Standard the following month, is the first continent-wide technical baseline covering sauna rooms, warm-air rooms, steam rooms, and soft steam rooms in public facilities. National standards bodies across the EU and EEA are obliged to adopt the text without changes by August 2026, at which point any conflicting national standards must be withdrawn.

It is a big deal, and not for the reason most American operators assume. EN 18164 is not a CE mark. It is not law. It is voluntary on paper. But it is also now the reference baseline for every European public sauna tender, retrofit, and insurance conversation, and Finnish experts are already arguing that it freezes a particular Central European idea of sauna rather than the real thing.

Key Facts: EN 18164:2026 covers design and construction of public sauna rooms, warm-air rooms, steam rooms, and soft steam rooms. CEN approval: January 26, 2026. National adoption deadline: August 2026. Scope explicitly excludes electrotechnical aspects (those still fall under EN 60335-2-53). Normative references include EN 16165 for slip resistance. European standards are voluntary unless incorporated by national law or contract.

What CEN Actually Passed

The publicly available preview of the final text confirms the structure. Scope: design and construction requirements for public climated rooms and associated equipment, with electrotechnical aspects explicitly excluded. Architecture: ten clauses covering classification, construction, ventilation, heating and temperature control, steam and humidification systems, lighting, and bibliography. Normative anchors: EN 16165 for slip resistance and EN 60335-2-53 for sauna heating appliances. Twenty pages total.

2018

CEN/TC 136 working group development begins

February 2025

prEN 18164 draft circulates publicly for comment

January 26, 2026

CEN formally approves EN 18164:2026

February 2026

European edition issued; first national publication records appear (Belgium Feb 25, Ireland and Sweden Feb 26)

March 12, 2026

Netherlands NEN-EN 18164:2026 gazette notice

March 16, 2026

Estonia EVS-EN 18164:2026 becomes valid

March 30, 2026

Iceland ÍST EN 18164:2026 enters into force

April 2026

Germany issues DIN EN 18164:2026-04; Austria's ÖNORM edition follows April 15

August 2026

Deadline for national adoption across EU/EEA; conflicting national standards must be withdrawn

National publication has moved fast and unusually uniform for an EN adoption. Germany, Belgium, Ireland, Sweden, Estonia, Iceland, Austria, the Netherlands, Denmark, Finland, and Slovenia have all surfaced national editions or publication notices. No national technical deviations have appeared in the catalogue entries reviewed.

National transpositions of EN 18164:2026 (as of April 2026)

Country | National edition | Status or date | Notes
Austria | ÖNORM EN 18164 | Issued April 15, 2026 | Current national edition via Austrian Standards
Belgium | NBN EN 18164:2026 | Published February 25, 2026 | Status active
Denmark | DS/EN 18164:2026 | March 2026 bulletin | Marked identical to EN 18164:2026
Estonia | EVS-EN 18164:2026 | Valid from March 16, 2026 | Also listed in EVS Teataja
Finland | SFS-EN 18164:2026:en | Listed April 8, 2026 in published standards | SFS product page not yet surfaced publicly
Germany | DIN EN 18164:2026-04 | Issue April 2026 | National edition sold in German and English
Iceland | ÍST EN 18164:2026 | In force March 30, 2026 | Announced March 31 via Staðlaráð Íslands
Ireland | I.S. EN 18164:2026 | Published February 26, 2026 | Marked equivalent to EN 18164:2026 via NSAI
Netherlands | NEN-EN 18164:2026 | Gazette notice March 12, 2026 | Official Staatscourant notice; direct NEN catalogue page not surfaced
Slovenia | SIST EN 18164:2026 | Catalogue entry April 9, 2026 | Full metadata not yet public
Sweden | SS-EN 18164:2026 | Approved February 26, 2026 | Status valid via SIS

That tight convergence matters. It means a sauna operator in Tallinn, Stockholm, Munich, and Dublin is now working from the same technical vocabulary for the first time, and design consultants exporting work across borders can stop rewriting specs for every jurisdiction. For Bulgaria, Croatia, Cyprus, Czech Republic, France, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Norway, Poland, Portugal, Romania, Slovakia, and Spain, national transposition records have not yet surfaced in public catalogues as of mid-April, but the CEN adoption obligation applies through the August deadline.

What the Standard Actually Says About a Sauna

EN 18164 defines four public room classes: sauna room, warm-air room, steam room, and soft steam room. These are not marketing labels. They are technical classes with climate envelopes attached, and the most significant one is the sauna-room definition in Section 4.1. The text, as reproduced by Saunologia's Lassi Liikkanen in his April 2026 analysis of the standard, reads:

The sauna room is made of timber with ascending stepped benches and with a room climate of 80°C to 105°C and a relative humidity of < 10 % measured 1 m above the top bench, which is set by a stone-filled heater.
EN 18164:2026, Section 4.1 (reproduced in Saunologia, April 2026)

Translated to US customary: the sauna-room class requires a measured climate of 176°F to 221°F, relative humidity under 10 percent, measurement taken roughly three feet above the top bench, with a stone-filled heater producing the heat and stepped timber benches defining the room. That is an unusually specific definition for a European standard.

Beyond Section 4.1, Liikkanen's analysis (the most detailed public reading of the paid standard in circulation) summarizes these additional requirements from the document:

EN 18164:2026 sauna-room requirements, as reported by Saunologia:
• Climate: 176°F to 221°F, RH < 10 percent, measured three feet above the top bench
• Wood cladding: at least 65 percent of walls and ceilings
• Heat-up: room must reach specified conditions within 60 minutes
• Ventilation: at least five air changes per hour, or a CO2-regulated control strategy
• Benches: minimum 0.8 inch gap from the floor, removable construction for cleaning
• Wall insulation: minimum 1.75 inches of mineral wool in stud walls, or 2.4 inches in solid log walls
• Doors: must open outward without obstruction
• Hygiene: surfaces below 131°F require treatment to prevent microbiological growth

The soft-steam class allows much lower temperatures at much higher humidity. Liikkanen reports the class permits conditions up to roughly 158°F at 90 percent relative humidity. The steam-room and warm-air classes fall in between. The exact numeric envelopes for those three classes are not as cleanly quotable as Section 4.1 because the paid text is copyrighted and only a short excerpt has been circulated publicly.

The commercial consequence of that taxonomy is straightforward. Every public room in Europe currently marketed as a sauna now has to answer a simple question: does it actually meet the sauna-room class under EN 18164, or is it technically a warm-air room sold under the wrong name? Plenty of lower-temperature public rooms, especially those catering to older or heat-sensitive guests, will not clear the sauna-room bar. The lowest-friction path for those operators is honest reclassification in brochures, booking flows, and on-site signage rather than a retrofit that may not be economically worth it.

EN 18164 baseline vs. prior practice, at a glance

Topic | EN 18164 baseline | Prior practice | What matters now
Taxonomy | Four public room classes: sauna, warm-air, steam, soft steam | Europe-wide public sauna taxonomy fragmented, nationally defined or not defined at all | Common naming grid for tenders, specs, and marketing
Sauna definition | Stepped timber benches, stone-filled heater, 176 to 221°F, RH under 10 percent, 65 percent wood coverage | International Sauna Association used a similar high-temp definition; Saunologia argues Nordic real-world practice is cooler (~169°F average) | Rooms culturally treated as saunas may fail the technical sauna-room class
Ventilation | Dedicated Clause 6; at least five air changes per hour or CO2-sensitive control | Widely variable practice; no Europe-wide predecessor spec | Indoor air performance moves from background to core compliance topic
Materials and hygiene | Dedicated clauses on wet-area finishes, slip resistance, room drying, timber treatment, bench detailing | Central European guidance existed, but clause-level comparison was not public | Cleanability, bench detailing, drying, and wet-floor performance become documentable design items
Accessibility | Accessible pathways and floors covered; broader universal-design treatment limited | Handled through local building and accessibility law | Accessibility still sits mostly outside EN 18164, weakening its one-stop value
Operations and training | Construction-led; no staffing, supervision, or ritual operations clauses | Operational rules lived in trade-association guidance | Operators still need separate SOPs, training, and local house rules
Certification and labeling | No dedicated labeling or CE-style conformity chapter; no linked directives | Voluntary standards are normal in Europe unless referenced by law | Immediate effect is market and best-practice pressure, not automatic certification

Built for Architects, Not Operators

EN 18164 is a construction standard. That is the single most important thing to understand about it. The table of contents has dedicated clauses for wall buildup, ceilings, doors, windows, wet-area finishes, slip resistance, ventilation, room drying, heating and temperature control, steam and humidification technology, and lighting. It does not have a chapter on staff training, infusion procedures, supervision ratios, or house rules. Those still live in trade-association guidance, employer SOPs, and local public-health law.

Electrotechnical aspects are expressly excluded from the scope. For anything involving the heater itself, the standard defers to EN 60335-2-53, which is the international electrical safety baseline for sauna heating appliances. That is the same IEC-rooted standard the United States finally adopted as UL 60335-2-53 in June 2025. The practical effect is that a European public-sauna project now has to manage at least two standards in parallel: EN 18164 for the room, and EN 60335-2-53 for the box that heats it.

Where the Nordic Pushback Actually Lands

The standard has supporters and critics, and the two sides agree on almost nothing. Germany's Deutscher Sauna-Bund framed DIN EN 18164 as a constructive safety benchmark in a late-March news item and published a paid explainer through its own channels. The Finnish Sauna Society flagged the release in its March 31 magazine with a short nutshell summary. The sharpest public critique is Liikkanen's, and it is worth reading closely because it is the first serious technical objection to a pan-European sauna baseline from inside the Finnish tradition.

Liikkanen's four specific critiques, in his own words:

The sauna definition is too narrow. Pointing to epidemiologist Jari Laukkanen's long-running Kuopio cohort data, Liikkanen notes that most Finnish saunas measured in that research operate around 169°F (76°C) on average, below the 176°F (80°C) floor in Section 4.1. His language is blunt: plenty of real Finnish saunas, he writes, "would not meet the standard criteria because they are too cold or don't have enough wood cladding." This is a cultural objection with a research citation behind it, not a stylistic complaint.

The 60-minute heat-up requirement punishes large-stone-mass heaters. Liikkanen writes that the requirement "will be difficult for some heater manufacturers to digest" and that it "invalidates the use of heaters with a notable stone mass." Those are the heaters favored by many traditional Finnish builders for thermal stability and löyly quality. If his reading holds against the full text, this is the single clause most likely to move product roadmaps.

The soft-steam class is too permissive. Liikkanen calls the definition "ambiguous" and "all-encompassing," and notes it can include conditions he describes as "uninhabitable for humans (say, 70°C at 90 % RH)," which works out to roughly 158°F at 90 percent relative humidity. A class that covers both something pleasant and something medically risky is, he argues, not much of a class.

Accessibility is thin. Liikkanen writes that the document contains "hardly any points on 'universal design or accessibility,'" a meaningful gap given the EU's broader equality agenda. He also argues that controlling carbon dioxide matters more than hitting a fixed air-exchange rate: "more important to control CO2 than produce a certain ventilation volume." Both points are explicitly his view, not language in the standard.

Liikkanen is measured about the document overall. He calls it Europe's first comprehensive sauna standard and treats it as a meaningful step rather than a failure. What he does not do is pretend that a Central European definition of sauna captures the living Nordic and Baltic tradition. Neither side in that argument is entirely wrong.

Voluntary on Paper, Mandatory in Practice

Both the European Commission and CEN-CENELEC are explicit that European standards are voluntary unless referenced by legislation. The EVS product page for EN 18164 shows no linked directives or regulations. This is not a CE-marking instrument and does not create a new conformity pathway for public-sauna construction.

Treating it as "optional" is a mistake anyway. Four places will start quoting EN 18164 almost immediately: procurement specifications written by architects and consultants, local building-approval discussions where officials cite recognized technical practice, internal risk management at facility operators, and post-incident liability arguments after slips, door malfunctions, overheating claims, or air-quality complaints. In any of those settings, a facility that cannot demonstrate alignment with the standard has to explain why.

Insurance underwriters have not yet published bulletins specifically on EN 18164, but the standard's coverage of slip resistance, door hardware, heating control, ventilation, and hygiene-adjacent construction details overlaps cleanly with the things loss adjusters ask about after a claim. Expect harder questions on room classification, design records, and maintenance documentation in the next renewal cycle for European public-sauna policies.

What U.S.-Facing Manufacturers Should Watch

For American operators, EN 18164 looks like a European problem. It is more complicated than that for any manufacturer with a meaningful European footprint. Harvia sells across all of it. KLAFS is a German household name under Kohler ownership since 2023. HUUM, SaunaLife, and Auroom are all Estonian brands exporting into the same regulatory block. Harvia's 2025 full-year numbers show how much of the group's volume depends on European commercial projects that will now specify to EN 18164.

The structural pressure on manufacturers is on documentation and positioning, not a new certification fee. There is no new CE label to chase. What changes is that European tenders will increasingly specify room type, heating strategy, ventilation assumptions, humidification technology, and construction context in the standard's language. Brands with clean technical data sheets and a clear story about how their heater, controller, and bench package fits the sauna-room class will win a disproportionate share of specification-driven work. Brands selling on price alone into public projects will find the conversation harder.

There is a U.S. angle worth flagging. European manufacturers newly comfortable with EN 18164 also build to EN 60335-2-53, which is now the same base text as the U.S. UL 60335-2-53 First Edition. For brands contemplating a bigger push into North America, the regulatory translation work just got easier. That matters for the competitive balance as domestic and Canadian brands wrap up their own recertification under the new U.S. sauna heater standard.

For builders, installers, and design consultants working on European jobs, the practical checklist is short. Decide room by room which class each space should declare. Confirm that every space marketed as a sauna can actually hit the required climate envelope. Document ventilation intent, not just ventilation openings. Keep slip-resistance evidence on file against EN 16165. And do not assume EN 18164 covers the heater itself. It does not.

For the first time, a public sauna project anywhere in Europe has a single technical dictionary to work from. That is genuinely useful. It will tighten procurement, reduce fake-sauna marketing, and give insurers and inspectors a defensible reference point. It is also going to force a cultural argument that the standard's drafters mostly avoided. A room that reaches 176°F and keeps humidity under 10 percent may clear the sauna-room bar on paper. Whether that is what Finns, Estonians, or Latvians actually mean by a sauna is a separate question, and it is one the Nordic critique is right to keep open.

EN 18164:2026 is voluntary in formal EU-law terms and already becoming the reference baseline for public-sauna design in Europe. The question is no longer whether the standard matters. It is how quickly operators, manufacturers, and regulators treat it as the new default grammar of public heat, and whether the Nordic pushback is strong enough to force a second edition that looks more like the real tradition. Watch the August 2026 adoption deadline, watch the next round of commercial tenders in Germany and the Netherlands, and watch whether Harvia, HUUM, and the other Nordic heater brands start publishing EN 18164 compliance packs of their own.