The paper presents a scheme to represent the impact of urban buildings on airflow in mesoscale atmospheric models. The scheme parameterizes the effects of buildings on grid-averaged variables without explicitly resolving them. An urban quarter is characterized by horizontal building size, street canyon width, and building density as a function of height. The module calculates the impact of horizontal (roofs and canyon floors) and vertical (walls) surfaces on wind speed, temperature, and turbulent kinetic energy (TKE). The computation of shortwave and longwave radiation accounts for shadowing and radiation trapping effects. The TKE equation is modified to account for the presence of buildings. The parameterization is tested in a bidimensional city over flat terrain, showing better reproduction of urban features compared to traditional approaches based on roughness length modification. The new parameterization also significantly impacts the dispersion characteristics of air pollutants in urban areas. The study highlights the importance of accurately representing urban surface characteristics in mesoscale models to improve air pollution dispersion simulations.The paper presents a scheme to represent the impact of urban buildings on airflow in mesoscale atmospheric models. The scheme parameterizes the effects of buildings on grid-averaged variables without explicitly resolving them. An urban quarter is characterized by horizontal building size, street canyon width, and building density as a function of height. The module calculates the impact of horizontal (roofs and canyon floors) and vertical (walls) surfaces on wind speed, temperature, and turbulent kinetic energy (TKE). The computation of shortwave and longwave radiation accounts for shadowing and radiation trapping effects. The TKE equation is modified to account for the presence of buildings. The parameterization is tested in a bidimensional city over flat terrain, showing better reproduction of urban features compared to traditional approaches based on roughness length modification. The new parameterization also significantly impacts the dispersion characteristics of air pollutants in urban areas. The study highlights the importance of accurately representing urban surface characteristics in mesoscale models to improve air pollution dispersion simulations.