HEDWIG - Collection of measurement data to assess the impact of green buildings | Continuous measurements

Green infrastructures (GI) are becoming an important strategy for climate change adaptation. Although their positive effects – such as evaporative cooling, shading and biodiversity –are qualitatively recognised, reliable, standardised measurement data for quantitative impact assessment in planning practice are usually lacking. The HEDWIG project addressed this gap by carrying out continuous systematic monitoring over a period of two years on 4 representative greened roofs and facades each, in Vienna and Lower Austria. The aim was to evaluate adult building greenery systems, and to determine the effects of standard-compliant greening technologies, representative vegetation and performance parameters. Data and analyses results serve as a data base for thermal building simulations and for the optimisation of planning processes. A measurement setup for permanent data registering was designed to ensure valid data collection and comparability across sites. Onsite data were collected over a period of 2 years (2024 to 2025), whereby unified sensor settings were installed for the green facades and adjusted for green roofs accordingly. Measurements included: air temperature [in front of/above and behind/under greenery]: MS WTS305 (MILESIGHT) and SenseCAP S2101 (MILESIGHT); humidity [in front of/above and behind/under greenery]: MS WTS305 SenseCAP (MILESIGHT) and S2101(MILESIGHT), solar radiation [in front of/above and behind/under greening]: EKO ML-02-5P wind speed: MS WTS305 (MILESIGHT), wind direction: MS WTS305 (MILESIGHT), atmospheric air pressure: MS WTS305 (MILESIGHT), heat flow (behind the living wall modules/in the roof substrate): Hukseflux HPF01 (CAMPELL Scientific). Data transfer was managed via cloud transfer. Data were collected on a 10 min interval and saved as hourly means. Data provided enable to calculate reduction of solar radiation behind the leaf biomass and bioshading coefficients as key parameters per greenery type and location. For green roof substrates and for living wall systems additional heat flux data are available. Results The data evidenced that dense plant bodies can massively reduce solar radiation from impacting the building surface. During heat waves, a reduction of up to 97 % in solar radiation was measured behind leaf bodies of vertical greenery. Furthermore, modular greening systems with automatically irrigated vegetation carriers protect the building effectively from heat input. At the same time, the living wall elements form full shading on the façade and thus prevent the façade surface from heating up, increasing the longevity of the building envelope. In the case of green roofs, increasing substrate layer thickness improves water storage capacity, reduces substrate temperature and raises inertia in terms of heat flow This demonstrates that intensive green roofs react to temperature fluctuations with a time delay and keep rainwater in the substrate for longer. Conclusions and Outlook Data and results confirm the high effectiveness of greening as natural cooling systems and radiation shields. In particular, the high radiation reductions of the green bodies and the resulting reduced energy inputs are emphasised as an active climate change adaptation strategy. For the first time, an empirically validated database for different types of building greenery under real site conditions is provided. Calculated and derived parameters enable a more precise integration of green infrastructures into simulation tools. This publication provides the 2 -year data of continuous measurements collected in the HEDWIG project and generated at 4 representative greened roofs and facades each, in Vienna and Lower Austria as open data source. The project was funded by the FFG (Österreichische Forschungsförderungsgesellschaft). Further publicationsStangl Rosemarie; Jalits Nicole; Bintinger Rudolf; Mezger Lars; Spörl Philipp; Scharf Bernhard; Poiss, Maximilian; Pitha, Ulrike; Leitner, Elisabeth; Formanek, Susanne (2026): Projekt HEDWIG Erhebung von Mess-Daten zur Wirkungsabschätzung von begrünten Gebäuden. HEDWIG-Berichtsserie: Ergebnisbericht. Berichte aus Energie und Umweltforschung 59a/2026. Wien. Jalits, Nicole; Mezger, Lars; Spörl, Philipp; Scharf, Bernhard; Poiss, Maximilian; Pitha, Ulrike; Bintinger, Rudolf; Stangl, Rosemarie (2026): Projekt HEDWIG Erhebung von Mess-Daten zur Wirkungsabschätzung von begrünten Gebäuden. HEDWIG-Berichtsserie: Teilbericht Datenkatalog. Berichte aus Energie und Umweltforschung 59b/2026. Wien. Jalits, Nicole; Stangl, Rosemarie (2026): Studie im Rahmen des Projekts HEDWIG zur Abbildung des aktuellen Wissenstands im Bereich Dach- und Fassadenbegrünung. HEDWIG-Berichtsserie: Teilbericht Studie. Berichte aus Energie und Umweltforschung 59c/2026. Wien. Leitner, Elisabeth; Formanek, Susanne; Jalits, Nicole; Mezger, Lars; Bintinger, Rudolf; Stangl, Rosemarie (2026). Projekt HEDWIG Erhebung von Mess-Daten zur Wirkungsabschätzung von begrünten Gebäuden. HEDWIG-Berichtsserie: Teilbericht Ergebnisse aus dem Stakeholder*innenworkshop. Berichte aus Energie und Umweltforschung 59d/2026. Wien.