What is Warunki Techniczne?
Warunki Techniczne (WT) is a regulation issued under the Polish Construction Law (Prawo budowlane) by the Ministry responsible for construction. Its full title is Rozporządzenie Ministra Infrastruktury w sprawie warunków technicznych, jakim powinny odpowiadać budynki i ich usytuowanie. It sets mandatory minimum technical requirements for buildings in Poland, including structural safety, fire protection, acoustic performance, hygiene and energy performance.
The regulation is available through the ISAP database (Internetowy System Aktów Prawnych), which is the official Polish legal acts repository maintained by the Chancellery of the Sejm.
The 2021 Update: Key Changes for Energy Performance
The WT 2021 revision, which came into force on 1 January 2021, represented the third and most significant step in a phased tightening process that began in 2014. The changes applied to new buildings and to substantially renovated existing buildings requiring a building permit.
Primary Energy (EP) Requirements
The central metric in WT 2021 is the EP indicator — primary energy demand expressed in kWh/(m²·year). EP values are calculated using a national methodology that applies conversion factors (wi) to account for the primary energy content of different energy carriers (electricity, gas, biomass, district heating).
| Building type | Max EP kWh/(m²·yr) from 2021 | Max EP kWh/(m²·yr) before 2021 |
|---|---|---|
| Single-family residential (heated floor area ≤ 150 m²) | 70 | 95 |
| Single-family residential (heated floor area > 150 m²) | 70 | 95 |
| Multi-family residential | 65 | 85 |
| Residential — collective housing, dormitories | 75 | 95 |
The Polish EP calculation methodology uses standardised climate data and occupancy patterns. It is not the same as the Passivhaus Planning Package (PHPP) methodology used by PHI. A building meeting WT 2021 EP limits is not automatically Passivhaus certified, and vice versa — though there is significant overlap in the required technical measures.
Thermal Insulation Requirements for the Building Envelope
WT 2021 specifies maximum U-values for each element of the thermal envelope. These are design maxima — the actual as-built performance must meet or exceed these values. For windows, the maximum Uw requirement was reduced from 1.1 to 0.9 W/(m²·K).
| Envelope element | Max U W/(m²·K) — WT 2021 |
|---|---|
| External walls (zone I–III) | 0.20 |
| External walls (zone IV–V) | 0.25 |
| Roof and flat roof | 0.15 |
| Floor over unheated space or ground | 0.30 |
| Windows and balcony doors (heated rooms) | 0.90 |
| Roof windows | 1.10 |
| Entrance doors | 1.30 |
Poland is divided into five climatic zones (strefy klimatyczne) for building energy calculation purposes, ranging from Zone I (warmest, south-western Poland) to Zone V (coldest, north-eastern and mountain regions). The U-value requirements for walls vary between zones, but the window requirements are uniform across all zones.
Climate Zones in Poland
The division into climatic zones affects the design outdoor temperature used for heat loss calculations and impacts the required insulation thickness for walls and roofs, though not for windows. The coldest design temperatures range from approximately -16°C in Zone I to -24°C in Zone V (Zakopane and north-eastern borderlands).
For window sizing and orientation in passive design, solar irradiation data varies significantly between regions. Warsaw (Zone III) and Kraków (Zone II) receive notably different solar radiation totals and have different horizontal irradiation profiles through the heating season, which affects PHPP glazing optimisation.
Renewable Energy Requirement
WT 2021 introduced a requirement that at least a minimum share of energy for heating, cooling and domestic hot water should come from renewable energy sources or high-efficiency cogeneration systems. The specific threshold depends on the energy carrier and system type. This requirement is defined in §328 and is separate from the EP limit.
In practice, this pushes design toward heat pump systems (using electrical energy with renewable fraction per the wi coefficient), biomass boilers, or solar thermal panels. For window design, it reinforces the logic of maximising passive solar gain through south-facing glazing to reduce the overall heating demand before the renewable energy requirement applies.
Energy Performance Certificates
Every new building in Poland must receive a świadectwo charakterystyki energetycznej (energy performance certificate, EPC) before it can be occupied. The certificate is issued by a qualified energy assessor (audytor energetyczny or osoba uprawniona) and is valid for ten years. It must be prepared according to the methodology defined in the Minister's regulation on energy performance certification (Rozporządzenie w sprawie metodologii wyznaczania charakterystyki energetycznej).
The EPC includes the EP value, the EK value (final energy demand) and the CO₂ emission indicator. Window U-values entered into the calculation must correspond to the installed product's CE declaration of performance. Discrepancies between declared and actual installed values are an audit risk in buildings subject to regulatory inspection.
Comparison with Passivhaus Standards
Passivhaus certification is voluntary and administered by the Passive House Institute (PHI, Darmstadt). It is not a Polish regulation but is applied by some Polish developers and architects. The PHI criteria for central European climate include:
- Heating demand ≤ 15 kWh/(m²·yr) per treated floor area (TFA)
- Primary energy ≤ 120 kWh/(m²·yr) for Passivhaus Classic
- Airtightness n50 ≤ 0.6 h⁻¹
- Window Uw typically ≤ 0.8 W/(m²·K) for central European climate
A WT 2021-compliant building with EP = 70 kWh/(m²·yr) is not a passive house. Passive house performance typically requires investments in insulation, glazing and heat recovery ventilation that go substantially beyond the WT 2021 minima. The gap is particularly visible in air leakage: WT 2021 has no airtightness requirement for single-family homes (a blower-door test is not mandatory), while PHI certification requires measured n50 ≤ 0.6 h⁻¹.
References: Rozporządzenie WT — ISAP · Passive House Institute · Ministerstwo Infrastruktury — energia