Urbanization and rapid construction have transformed modern cities. With increased population density, the quality of indoor and outdoor environments has become a critical concern. Two major issues, air pollution and noise, have emerged as persistent problems that affect health, productivity, and quality of life. Conventional building materials focus on structural strength, durability, and aesthetics. They rarely address environmental challenges beyond their basic functions. Recent advances in material science and architectural design are changing this approach. New building materials can now actively purify air, absorb pollutants, and reduce noise. Integrating these materials into construction can transform buildings into systems that support human health and improve urban living conditions.
Urban Challenges: Air and Noise
Urban challenges in India are increasingly defined by air and noise pollution, both of which have significant health and environmental impacts. India is ranked as the world's third most polluted country, with an average annual PM2.5 concentration of 78.7 µg/m³ in 2024, according to Smart Air. Prolonged exposure to fine particulate matter reduces an average Indian’s life expectancy by 5.3 years, according to the Air Quality Life Index (AQLI). Exposure to these particles contributes to diseases such as stroke, heart disease, lung cancer, chronic obstructive pulmonary disease, and respiratory infections, according to the World Health Organization. Noise pollution further exacerbates urban health challenges.
In Bengaluru’s BTM Layout, maximum decibel levels recorded in February 2025 were 95.7 dB during the day and 91.4 dB at night, exceeding WHO-recommended limits of 55 dB during the day and 45 dB at night, according to The Times of India. Several other urban areas in India recorded noise levels exceeding 100 dB in 2023, surpassing safe limits. Collectively, these issues have significant implications for public health, productivity, and overall quality of life in rapidly urbanizing cities.
Photocatalytic Materials for Air Purification
Photocatalytic materials provide a way to improve indoor air quality without active intervention. These materials contain compounds, such as titanium dioxide (TiO₂), which react with light to break down pollutants. When ultraviolet light strikes these materials, a chemical reaction occurs. Nitrogen oxides, volatile organic compounds, and particulate matter are converted into harmless substances such as carbon dioxide and water.
These materials are applied to concrete, glass, ceramics, and paint coatings. They not only improve air quality but also reduce maintenance. Surfaces coated with photocatalytic materials tend to remain cleaner as organic matter and dirt are broken down over time. Buildings equipped with photocatalytic façades can reduce surrounding air pollutants and contribute to environmental improvement at the street level.
The advantage of photocatalytic materials lies in their passive functioning. They continuously break down pollutants as long as they are exposed to light. This makes them suitable for walls, windows, and external surfaces exposed to sunlight. Interior applications require materials combined with artificial lighting sources capable of triggering the chemical reaction.
Biophilic Design and Green Walls
Incorporating natural elements into buildings is another method to improve air quality. Plants absorb carbon dioxide and release oxygen, helping to purify the air. Certain species, such as the snake plant, peace lily, and spider plant, also remove chemical pollutants like formaldehyde and benzene.
Beyond individual plants, green walls and vertical gardens are increasingly used in urban environments. These walls consist of living plants embedded in a support structure. The foliage and growing medium absorb pollutants from the air while reducing noise through sound dampening. Soil and plant layers act as buffers that absorb and scatter sound waves. In addition to improving air quality and acoustics, green walls regulate temperature by reducing heat absorption. They can lower energy demands for cooling and heating in buildings.
Green roofs and rooftop gardens further expand these benefits. They provide insulation, reduce the urban heat island effect, and contribute to environmental management. When combined with other material innovations, these natural systems make buildings active participants in controlling their environment.
Acoustic Innovations in Building Materials
Noise control in buildings requires materials that absorb, block, or isolate sound. Porous and dense materials are commonly used for these purposes. Traditional options like fiberglass and foam are effective in absorbing sound but may not be environmentally sustainable. Newer materials, such as bamboo, cork, and recycled rubber, offer similar or improved performance while reducing environmental impact.
Porous materials absorb sound by allowing waves to enter small voids and dissipate energy as heat. They are effective at controlling high-frequency sounds. Dense materials, such as composite panels, block sound from transmitting through walls and floors, reducing low-frequency noise. Advanced composites combine multiple layers, including dense cores and absorptive surfaces, to improve performance across a wide range of frequencies.
Acoustic panels can be used in offices, classrooms, hospitals, and public spaces to improve comfort. They provide measurable reductions in noise levels and help create environments suitable for work and rest. Integrating these materials into walls, ceilings, and floors allows buildings to manage acoustic conditions without relying solely on mechanical systems.
Emerging Approaches
Beyond standard photocatalytic and acoustic materials, several emerging approaches are gaining traction:
- Hybrid Coatings: New coatings integrate photocatalytic nanoparticles with antimicrobial properties. These materials reduce pollutants and microbial contamination, providing cleaner surfaces in hospitals and schools.
- Porous Concrete and Ceramics: Porous concrete blocks and ceramic panels can trap dust and particulate matter from the air while reducing the transmission of sound through walls.
- Ventilated Façades: Double-skin or ventilated façades allow airflow through the building envelope. When combined with photocatalytic materials or vegetation layers, these façades actively filter incoming air and improve acoustic insulation.
- Nano-Enhanced Panels: Panels infused with nanomaterials can capture ultrafine particles that conventional materials cannot. These panels are particularly useful in high-traffic urban areas.
- Hybrid Green-Acoustic Systems: Integrating plants with engineered acoustic substrates creates dual-function walls that purify air and absorb sound simultaneously. These systems are applied in transport hubs, office lobbies, and residential buildings near highways.
Integrated Solutions for Air and Noise
The most advanced approach is to combine air purification and noise reduction in a single material or system. Green walls, for instance, simultaneously remove pollutants from the air and absorb sound. Composite panels with embedded photocatalytic particles and porous structures can perform both functions. These integrated solutions are particularly valuable in urban high-rise buildings, transport hubs, and areas with dense traffic.
Urban planners have begun using multifunctional barriers along highways and railway lines. These barriers incorporate sound-absorbing materials, plant-based filtration, and photocatalytic coatings. They improve air quality for nearby communities while reducing exposure to traffic noise. In residential buildings, combining green walls, acoustic panels, and photocatalytic coatings creates indoor environments that are quieter and healthier.
Applications
- Residential buildings (apartments, homes)
- Commercial offices
- Educational institutions (schools, colleges)
- Hospitals and healthcare facilities
- Public infrastructure (train stations, airports, bus terminals)
- Highways and urban roads
- Industrial spaces (factories, warehouses)
Cities like Bengaluru have begun integrating green walls, rooftop gardens, and multifunctional barriers into urban planning. Such initiatives address multiple environmental challenges, providing measurable benefits to residents. Combining materials with smart building technologies allows monitoring of air quality and noise levels, with the potential to automatically adjust ventilation or environmental controls.
Companies Providing Air-Purifying and Noise-Reducing Building Materials in India
- Zuari Cement – Offers photocatalytic cement and coatings that break down pollutants and maintain cleaner surfaces.
- ELT India – Provides modular green wall systems for facades and interiors, improving air quality and aesthetics.
- Natura India – Specializes in vertical gardens and plantscaping for residential and commercial projects.
- BreatheEasy Consultants – Supplies indoor air purifiers and customized air quality solutions for homes, offices, and public spaces.
- Prana Air – Provides air quality monitors, sensors, and fresh air machines for building-wide air management.
- Magneto – Develops electronic air cleaners and multi-stage filtration systems for large commercial and industrial spaces.
- Respirer Living Sciences – Focuses on urban air quality monitoring and climate solutions for infrastructure projects.
- Klenviron Technologies – Offers PAMARES systems to reduce particulate matter in indoor environments.
- AlgaClean India – Provides algae-based coatings that help improve air quality on building surfaces.
Challenges and Considerations
There are challenges in adopting these materials. Photocatalytic surfaces require light for effective functioning. Interior spaces with low light may need artificial UV sources. Green walls and vertical gardens require maintenance, including water, nutrients, and pruning. Acoustic materials must be designed with fire safety, structural load, and cost in mind.
Coordination among architects, engineers, and contractors is essential. Design codes and standards may require updates to include multifunctional materials. Cost, maintenance, and environmental factors need careful consideration to ensure long-term performance.
Future Directions
Research in nanotechnology, material science, and sustainable architecture continues to evolve. Nanoparticles in coatings can remove pollutants more efficiently. Bio-based acoustic panels offer reduced environmental impact. Smart building systems integrated with these materials provide real-time monitoring of air and noise, allowing dynamic adjustment to environmental conditions.
Other potential developments include:
- Self-cleaning green façades that combine plants, microbial action, and photocatalytic coatings.
- Modular panels that can be retrofitted to existing buildings to improve indoor air and acoustic quality.
- Smart sensors that adjust airflow, humidity, and ventilation in response to pollutant and noise levels.
As urban populations grow, the use of multifunctional building materials will become increasingly important. These materials provide solutions that are proactive rather than reactive. They create buildings that support human health, reduce environmental impact, and improve urban quality of life.
Conclusion
Addressing air pollution and noise requires a shift in how buildings are designed. Conventional materials offer structural integrity but little environmental interaction. Emerging materials—photocatalytic coatings, green walls, acoustic composites, and hybrid systems—allow buildings to actively improve indoor air quality and reduce noise. Integrated solutions combine these benefits, supporting healthier and more sustainable urban environments.
By adopting these materials and approaches, urban buildings move beyond the role of shelter. They become active systems that manage environmental quality, support human health, and contribute to sustainable city planning. The future of construction lies in materials that perform multiple functions, addressing the challenges of urbanization while improving the quality of life for inhabitants.
Images- verdeprofilo.com, materialsource, prkwilliams.com
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