INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH, cilt.3, sa.5, ss.1-23, 2025 (SCI-Expanded)
Rethinking urban models
requires resilient designs providing solutions to environmental problems at the
building scale. Urban Heat Islands (UHI) and Urban Noise Islands (UNI) often
coexist and significantly affect human health and comfort. This article aims to
examine dual-function building envelope materials for reducing urban heat and
noise islands using the literature review method. Dual-functional building envelope materials provide
versatile benefits such as increasing energy efficiency, mitigating
environmental challanges in densely populated areas, and improving individual
and social health and comfort, in addition to their thermal and acoustic
benefits. The use of these materials in building envelopes supports the climate
adaptation of cities and provides resource efficiency. High albedo cool materials used for excessive heat
reduction can be in the form of cool roofs or cool walls. High reflective
materials, cool colored materials, retro-reflective materials, photoluminescent
materials, thermochromic materials and sustainable materials are the most
common among the cool material alternatives. The use of natural and local white
colored gravel of various sizes on cool roofs is a low-cost and efficient
approach to UHI reduction. Cool colored materials reflecting the near-infrared
part of the solar spectrum bring a suitable solution for historical buildings
where white color application is not appropriate. Highly reflective materials
combat heat-related risks by reflecting incoming solar radiation directly back
to their source due to their special content. Photoluminescent materials, which
are still in the research phase, and thermochromic materials that change color
when they reach a predetermined temperature are other solutions used to prevent
heat-induced problems. Recycled or paraffin, biowaste oil added Phase Change
Materials (PCM) also offer environmentally friendly, sustainable solutions for
this case. In terms of UNI mitigating techniques, sound absorbing materials
with high sound absorption coefficient and low density are widely preferred for
building envelopes. Since high albedo materials generally have low sound
absorption capacity, although reduction in heat- and noise-related threats is
possible separately with the building envelope materials to be selected, multifunctional
surface design diminishing both UHI and UNI effects simultaneously still
involves various challenges. However, there are various strategies including
applications of green walls and green roofs. Innovative approaches such as the
use of PCM in pavements or the conversion of noise into green electricity using
resonators or acoustic metamaterials also exist. While such solutions have not
yet been widely found in practical applications, they are promising for the
resilient smart cities of the future. Further experimental validation is needed to evaluate
the long-term performance, cost-effectiveness and climate-specific
applicability of multifunctional materials.