Smog in Kraków 2024 — AGH study and the role of thermal upgrades

Q: Do PIR insulation boards help meet the WT 2021 requirements?

Yes. PIR boards with λD 0.022 W/(m·K) (termPIR® AL) or 0.019 W/(m·K) (termPIR® MAX 19 AL) make it possible to achieve the U values required by WT 2021 (roof 0.15 W/m²K, wall 0.20 W/m²K) at a thickness 30–50% smaller than with mineral wool. This is crucial in building renovation, where limited structural depth makes it difficult to apply traditional insulation thicknesses.

Kraków is winning the fight against smog — AGH study confirms the effectiveness of the anti-smog act

A study commissioned by Krakowski Alarm Smogowy (Kraków Smog Alert) and carried out by researchers from the AGH University of Science and Technology delivers hard data: the anti-smog act in force in Kraków since 1 September 2019 has genuinely reduced concentrations of particulate matter and benzo(a)pyrene. However, the fight for clean air is not only about fuel regulations — it is also about the energy efficiency of buildings. Thermal upgrades using PIR insulation boards with low λ_D directly reduce the demand for thermal energy, and consequently the emission of dust from fireplaces, coal-fired boilers and gas peak-load sources.

What did the AGH study reveal?

The analysis was carried out by Prof. Piotr Kleczkowski and Katarzyna Kotarba, M.Sc.Eng., of AGH. They compared data from measurement stations in Kraków and the Małopolska region over a multi-year horizon covering the introduction of the anti-smog act.

Indicator	Period	Kraków	Małopolska
PM10 (particulate matter)	2012/13 → 2019/20	-45.42%	-28.73%
PM2.5 (fine particulate matter)	2012/13 → 2019/20	-43.76%	-32.15%
Benzo(a)pyrene (B(a)P)	2014/15 → 2019/20	-42.82%	+14.41%

Particularly significant is the drop in benzo(a)pyrene concentrations — a carcinogenic polycyclic aromatic hydrocarbon (PAH) that damages the adrenal glands, liver, cardiovascular and immune systems. While Kraków itself recorded a decrease of over 42%, concentrations across the region increased by more than 14% over the same period. This is direct evidence that limiting the burning of solid fuels works locally and on a targeted basis.

According to estimates, around 1,800 active coal-fired stoves still remain in the city — still a source of low-stack emissions, but their number has decreased twentyfold over the past decade.

The “Kraków doughnut” — limits to the act’s effectiveness

Kraków lies in a basin surrounded by higher-altitude municipalities forming the so-called “Kraków doughnut”. The anti-smog act does not cover these areas, and pollutants from individual stoves in the surrounding municipalities are transported by air masses into the city centre, especially under thermal inversion conditions.

For this reason, reducing the energy demand of buildings — both in Kraków and in the neighbouring municipalities — remains a key, long-term tool for protecting air quality. The lower the heat losses through building envelopes, the less fuel is fed into boilers, regardless of their type.

WT 2021 and the role of PIR insulation in emission reduction

The Technical Conditions in force since 1 January 2021 (WT 2021 — Polish Technical Conditions 2021) tightened the requirements for the heat transfer coefficient U for building envelopes:

Building envelope	U max per WT 2021
Roof / flat roof	0.15 W/m²K
External wall	0.20 W/m²K
Floor slab over an unheated basement/garage	0.25 W/m²K
Ground-bearing floor	0.30 W/m²K

PIR insulation boards with λ_D = 0.022 W/(m·K) — such as termPIR® AL — make it possible to achieve these values at a significantly smaller thickness than mineral wool (λ ~ 0.035–0.040) or EPS (λ ~ 0.031–0.038).

Example: ETICS external wall

To achieve U ≤ 0.20 W/m²K in a typical wall built of ceramic blocks, you need:

~18 cm of mineral wool (λ 0.036)
~16 cm of facade EPS (λ 0.031)
~10 cm of termPIR® ETX (λ_D 0.025–0.027) — a vapour-permeable board with a glass fleece facing, dedicated to ETICS on the basis of ETA 17/0066

A smaller insulation thickness in the ETICS with termPIR® ETX system means shorter anchors, narrower reveals and less intervention into architectural detailing — which is particularly relevant when modernising Kraków’s existing building stock.

Thermal upgrade of Kraków’s heritage buildings

Old Town, Kazimierz, Podgórze — these are districts where external insulation is often impossible due to facade protection. The solution for buildings under conservator supervision is internal insulation using the termPIR® AL/GK composite — a PIR insulation board with a gas-tight aluminium facing, factory-bonded to gypsum plasterboard.

The internal insulation system termPIR® AL/GK simultaneously provides a vapour barrier function (Al foil) and a ready substrate for painting, eliminating the risk of interlayer condensation typical of incorrectly executed internal insulation.

Pitched roofs and tenement buildings — where most heat is lost

In Kraków’s tenement buildings, uninsulated roofs and flat roofs account for as much as 25–30% of heat losses. The use of termPIR® AL over-rafter installation eliminates thermal bridges on the rafters and makes it possible to achieve U ≤ 0.15 W/m²K at a thickness of ~14–16 cm.

In projects with particularly high energy requirements (passive buildings, plus-energy buildings), it is worth considering the premium variant termPIR® MAX 19 AL with λ_D 0.019 W/(m·K) — the lowest on the market for PIR boards.

Frequently asked questions

How does a thermal upgrade contribute to smog reduction?

Insulating walls, roofs and floors lowers a building's thermal energy demand by as much as 40–60% compared to its pre-modernisation state. Lower demand means less fuel burnt — regardless of the heat source. On a citywide scale, the cumulative effect is significant: according to energy estimates, every 1 GJ of reduced final energy in coal-based heating reduces PM10 emissions by approximately 0.3–0.8 kg. With systematic thermal upgrades to Kraków's housing stock, the potential for reducing low-stack emissions is comparable to the effects of replacing boilers.

Do PIR insulation boards help meet the WT 2021 requirements?

Yes. PIR boards with λ_D 0.022 W/(m·K) (termPIR® AL) or 0.019 W/(m·K) (termPIR® MAX 19 AL) make it possible to achieve the U values required by WT 2021 (roof 0.15 W/m²K, wall 0.20 W/m²K) at a thickness 30–50% smaller than with mineral wool. This is crucial in building renovation, where limited structural depth makes it difficult to apply traditional insulation thicknesses.

Which PIR board should be used for ETICS, and which for a pitched roof?

For ETICS (external thermal insulation composite systems), a vapour-permeable facing allowing water vapour diffusion towards the render is required — termPIR® ETX with glass fleece is used, holding ETA 17/0066. For pitched roofs (over-rafter, between-rafter), the optimal choice is termPIR® AL with a gas-tight aluminium facing, which additionally serves as a vapour barrier. termPIR® AL is not used for ETICS and vice versa — the Al foil prevents proper vapour release from the render system.

Are PIR insulation boards fire-safe?

termPIR® boards in building systems (with a facing, in a closed envelope) are classified as B-s2,d0 in accordance with EN 13501-1 — flame-retardant, with limited smoke emission and no flaming droplets. This classification is fully compliant with WT 2021 requirements for typical applications in residential and public-use construction. For facilities with special non-combustibility requirements (class A2), an alternative is offered by GS MW sandwich panels with a mineral wool core.

Are thermal upgrades in Kraków eligible for funding?

Yes — the "Czyste Powietrze" (Clean Air) programme run by NFOŚiGW (the National Fund for Environmental Protection and Water Management) operates in Kraków and the Małopolska region, supporting the replacement of heat sources together with accompanying thermal upgrades (insulation of walls, roofs, ground-bearing floors, replacement of joinery). The subsidies cover, among other things, the purchase of insulation materials — including PIR boards. We recommend consulting your thermal upgrade project with a specialist in order to select optimal insulation thicknesses and types in line with current technical requirements and funding conditions.