In urban design, outdoor comfort is intricately linked to the overall sensory perception, or sense-scape, of the spatial realm, which can be described through human perception and physical metrics. Seen through a physical lens, outdoor comfort relates to the interplay between environmental factors such as sound, wind, climate, and smell, and urban form and landscape design. Urban areas in the vicinity of airports and flight paths possess a distinct sensescape, characterized by the visibility and audibility of airplanes. Visual and auditory appraisal of urban areas near airports is further complemented, and potentially influenced, by environmental indicators independent from aviation, such as temperature, humidity, and wind flow. To what extent urban form and landscape design affect the sound- and sensescape of such areas is yet not well understood. This research gap formed the starting point for the Urban Comfort Lab in 2020. The lab comprised a field lab built from shipping containers stacked around three courtyards, simulating three street/building typologies at full-scale. Although focussing foremost on the influence of urban design aircraft noise and the sound environment, climatic and air quality were studied in parallel. During the first phase of the project urban form and shifted to urban greenery in the second phase. Adopting a data-based approach, the lab’s constituent studies focussed on physical parameters, and in for one study, in relation to human perception and physiology. In this session, results are presented for various separate acoustic, climate, air quality and cross-disciplinary studies, all relating to the Urban Comfort Lab, particularly, to urban greenery.

Trees provide essential ecosystem services in the urban environment. From a noise pollution perspective, trees disperse and scatter sound waves in street canyons and urban courtyards. A handful of studies have been published on the sound attenuating effects of trees, or tree belts, in street canyons, none focusing on aircraft noise specifically. Compared to other environmental noise sources such as road and railway traffic noise, aircraft noise is emitted from a airborne source and enters street canyons from above. The effect of urban form and architectural design on aircraft noise is investigated at the Urban Comforti Laba full-scale, semi-controlled environment close to Schiphol airport. In three courtyards, continuous measurements of local sound pressure levels emitted by aircraft flyovers are recorded. For this experiment, 36 trees were placed in one courtyard. The sound measurements were processed to a-weighted sound exposure levels (ASEL) for each aircraft flyover. The recordings from the courtyard with trees were compared to the ASEL recorded by microphones in the same positions in a statistically similar, bare courtyard. Microphone ASEL differences between the courtyard with, and without trees were subsequently compared. For the exposed microphone in the tree courtyard, the ASEL decrease was dependent on aircraft operation. For the shielded microphone in the courtyard with trees, the mean decrease amounted to 1.1 dB(A). These differences in ASEL indicate that trees in courtyards scatter noise, both for noise entering the courtyard and for sound waves reflected by the courtyard walls. The results suggest that trees can be used as a measure for noise adaptive design in airport regions, as they scatter sound waves entering through through trunks, branches and pots.

Abstract Particulate matter (pM) is widely recognized as an important concern for public health, correlating with an increased risk of various severe medical conditions. Aircraft emissions are a major source of particular matter, leading to greater pM concentrations in the vicinity of airports and flight routes. Trees are often used as a climate adaptation measure in cities, but their impact on air pollution is complex. Previous research suggests that trees can both reduce and increase PM concentration, depending on their configuration and local meteorological variables.This study investigates the influence of tree configurations on PM concentration and its relationship with meteorological factors, such as wind speed and direction, humidity, and temperature. The study employs citizen sensors to measure PM concentrations and meteorological data from Davis weather stations. Multivariate regression models are used to analyse data. The hypothesis is that a dispersed tree configuration will negatively impact wind speed, resulting in higher PM concentrations compared to a straight-row configuration. The findings will provide valuable insights into the impact of aircraft emissions on PM concentration and its potential health effects in Hoofddorp. Additionally, the findings will inform management strategies for tree planting around Schiphol Airport and contribute to the development of effective mitigation measures to protect public health. Keywords: air quality – airport – particular matter – Urban comfort lab

This paper provides an overview of urban research on noise, glare, heat, and air quality, coverinboth individual domains and combined analyses. It is aimed at scholars in the field of built environment research, as well as urban designers and policy makers in metropolitan areas. Metropolitan issues are often multifaceted; for example, the urban heat island effect can be exacerbated by traffic noise, glare from glass walls, and the cumulative effects of waste heat and air pollution. Therefore, adopting a holistic approach is recommended to achieve dual benefits with minimal effort, enhancing overall comfort optimally. However, in-depth knowledge and expertise in each specific domain are required, which can create barriers for researchers with limited background in these areas. Consequently, this paper aims to provide a concise guideline for metropolitan researchers delving into urban comfort research. Due to time constraints, the sections on results, discussion, and conclusion remain incomplete in this draft version. The authors reserve the right to modify, add, or retract content in future versions of this manuscript.

Urban sensescapes of areas near airports and flight routes are characterized by the visual and auditory backdrop of airplane flyovers. Sensescapes relate to the interplay between human experience, environmental conditions, and spatiality. Urban form and landscape design influence, and interacts with, environmental indicators, such as sound and wind flow, but also temperature and climate. Despite being studied extensively for most environmental sound sources, the influence of urban form and landscape design had not been broadly studied for aircraft noise. Based on the premise that building and street design influence the propagation of aircraft noise, the Urban Comfort Lab started in 2021. Through the lens of outdoor comfort, the lab also initiated data-driven urban climate and air quality project, to identify crossovers with sound abatement strategies. During the past two years more than a dozen projects were undertaken on aircraft noise, urban climate, and air quality. Nearly all studies focussed on physical aspects, through measurements and data analysis. Most noise studies prioritise technical-physical aspects, overlooking human perception in assessing acoustical comfort. This motivates us to redefine outdoor acoustical comfort through multidisciplinary knowledge and techniques. In this article, we reflect on the project’s process and output, to distil lessons for current and future practice. Based on the studies undertaken over the past three years, we identified and prioritized questions and gaps for future research.