Search articles from the Journal of Living Architecture

The Journal of Living Architecture (JLIV) is published exclusive here, on the Living Architecture Monitor website. The magazine will publish the abstract of each published JLIV manuscript in the quarterly issue of the LAM, with a link to the full paper here.

Current Issue

A suite of microclimate variables affected germination of five Great Plains native plants seeded on an extensive green roof. Germination was significantly (~' = 0.05) greater in a greenhouse control versus the green roof for shortbeak sedge and prairie spiderwort (Carex brevior (35% versus 23% Tradescantia occidentalis 19% versus 0%). No significant germination difference between the greenhouse and green roof existed for two, warm-season species, Liatris squarrosa and Eragrostis spectabilis. Significant differences in microclimatic conditions between green roof plot locations suggest a heterogeneous environment can decrease seed germination. This impact was attributed to differences in the receipt of solar radiant energy, surface temperature, and vapor pressure deficit. Light reflection and thermal emission from the adjacent buildings supplied additional energy in some locations (depending on time of year or time of day) that varied greatly over only a few meters. Designers must carefully analyze microclimate impacts and consider those implications for plant selection and seeding. Establishment of some native seeds in high temperature zones may take more irrigation or benefit from mulching than those in moderate temperature zones. Increased seeding rates and targeted seeding dates may also be useful strategies. Future green roof research should examine germination across steep microclimate gradients, seed a wider suite of native plants to broaden plant biodiversity, and follow seedling development and mortality.

While much green roof research has been directed towards commercial and industrial buildings, less is known about the sloped roofs of residential buildings. The purpose of this study was to evaluate a pitched residential green roof system and determine its ability to retain stormwater runoff. In order to do this, 18 shingled roof models were constructed on three slope angles – 1°, 20° (5/12 pitch), and 40° (10/12 pitch) of which 9 were randomly fitted with a modular green roof system across three replications. The 42.1% mean stormwater runoff retention for the green roof systems of was significantly greater than the 18.3% for shingled roof decks. A residential product (Steep Paks®) performed within the conventional range of previous stormwater retention studies. The residential green roofs  effectively reduced stormwater runoff during periods of light
precipitation compared to periods of heavy precipitation. No difference was found in percent stormwater runoff retention between the three residential green roof slope angles.

Potted-plants have the potential for improving indoor air quality (IAQ), however there has been little research on the performance of green-walls as indoor biofilters. The aim of this investigation was to compare rates of air pollutant reduction with two commonly used indoor species, and to assess the effects of added substrate airflows on the capacity of green-wall modules to remove two prevalent indoor airborne contaminants - particulate matter (PM), and volatile organic compounds (VOCs), using benzene as model. The species tested were Chlorophytum comosum (Spider Plant) and Epipremnum aureum (Pothos). The results showed that each species could significantly reduce increasing doses of PM, with or without augmented substrate airflow, however benzene removal rates decreased with increasing aeration. The findings provide a first assessment of the ability of green-wall plants to reduce indoor air pollution, and responses to two types of pollutant, particulate and gaseous.