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| BedZED eco-village, London |
In the pursuit of sustainability, green buildings prioritize not only environmental efficiency but also the health and well-being of their occupants. A critical component of this approach is Indoor Environmental Quality (IEQ) — a measure of how indoor environments impact comfort, health, and productivity. From fresh air ventilation to acoustic control, improving IEQ is essential for modern buildings aiming to be truly sustainable. This article explores six core elements of IEQ and how they contribute to healthier, greener spaces.
OBJECTIVE
This topic encompasses various tangible environmental aspects: earth, air, water, fire, and space. In my earlier discussions, I explored the solar power system, representing "fire" in terms of energy; the rainwater harvesting system, a key component of "water"; and most recently, natural lighting, which corresponds to "space." Now, let's focus on Indoor Environmental Quality (IEQ), a crucial element linked to "air."
My goal is to deliver insights from my studies and work experiences in a straightforward and engaging way, making them accessible to everyone. I understand that many professionals struggle to persuade their clients to embrace sustainability in their projects. In my previous blog, "CLIENT-CENTERED SUSTAINABILITY: TailoringSolutions to Meet Client Expectations in Sustainable Architecture," I shared practical strategies for overcoming these challenges. By considering these suggestions, including the environmental aspect I will discuss in this article, we can work together to promote awareness and advocate for a more sustainable future.
GREEN BUILDING DESIGN STRATEGIES (ENHANCING THE SIX CORE ELEMENTS OF "IEQ"):
1. Healthy Environment
A green building starts with the commitment to a healthy indoor environment. This means designing spaces that reduce occupant exposure to toxins, support mental well-being, and encourage overall wellness.
Strategies include:
Maximizing natural daylight and views to the outdoors
Maintaining comfortable temperature and humidity levels
Using biophilic design elements, like indoor plants and natural textures
Example: The Bullitt Center in Seattle is often cited as one of the greenest commercial buildings in the world. It uses non-toxic materials, prioritizes natural lighting, and offers a visually pleasing environment that reduces stress and enhances well-being.
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| Bullitt Center, Seattle |
2. Fresh Air Ventilation
Good indoor air quality starts with adequate ventilation. Ventilation is vital for removing stale air and introducing fresh air, thus diluting indoor pollutants and enhancing comfort. Green buildings use mechanical and natural systems to bring in fresh air and remove stale indoor air. Here are key strategies:
Heat Recovery Ventilators (HRVs) to retain energy while bringing in fresh air
Demand-controlled ventilation based on occupancy and CO₂ levels, and to optimize airflow while conserving energy.
Use of operable windows in passive designs
Case Study: The Edge in Amsterdam uses a sophisticated smart ventilation system that monitors occupancy and air quality, adjusting ventilation accordingly. This ensures constant fresh air flow and energy efficiency, contributing to high occupant satisfaction.
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| The Edge, Amsterdam |
3. Exhaust Systems
These systems expel pollutants and humidity directly outdoors, maintaining better air quality indoors. Proper exhaust ventilation is essential for eliminating localized sources of pollutants, especially in:
Kitchens
Bathrooms
Laundry areas
Utility rooms
Green buildings ensure:
Exhaust fans vent directly to the outdoors
Systems are zoned to prevent air transfer between spaces
Use of energy-efficient fans and ducts
Example: In LEED-certified residential buildings, such as those in the BedZED eco-village in London (Please see the cover photo), separate exhaust systems are designed for different zones of the home, reducing cross-contamination and maintaining a hygienic indoor environment.
4. Low VOC Materials and Compounds
Volatile Organic Compounds (VOCs) found in paints, adhesives, flooring, and furnishings can off-gas harmful chemicals for months after application. Excessive exposure to VOCs can lead to health issues like:
Headaches
Respiratory irritation
Long-term chronic effects
Green buildings opt for low or zero-VOC materials to improve indoor air quality and reduce occupant health risks. To avoid this, green buildings use:
Low- or zero-VOC paints, sealants, and finishes
Certified GreenGuard or GREENGUARD Gold furniture and products
Non-toxic insulation and adhesives
Case Study: The Center for Sustainable Landscapes at Phipps Conservatory in Pittsburgh used low-VOC paints, adhesives, and sealants throughout construction, contributing to its WELL Building Standard certification for promoting occupant health.
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| Phipps Conservatory in Pittsburgh |
5. Dust-Free Interiors
Reducing dust buildup is key to minimizing allergens and particulate matter that compromise air quality. Dust can carry allergens, bacteria, and pollutants. To minimize dust accumulation, green building designs emphasize:
Smooth, easy-to-clean surfaces
Integrated entryway mats and grilles to trap dirt
Central vacuum systems or HEPA-filter vacuums
High-efficiency air filters (MERV 13 or above)
Example: In schools built to CHPS (Collaborative for High Performance Schools) standards, special attention is given to materials that resist dust accumulation, along with filtered ventilation systems to promote healthier learning environments.
Portable air cleaners or purifiers are also widely used in homes and offices. If you are interested, you might want to check out this model.
6. Acoustic Control
Sound plays a major role in occupant comfort and productivity. Noise pollution negatively affects productivity, concentration, and mental health. Green buildings aim for a quiet, acoustically comfortable indoor environment by:
Using acoustic ceiling tiles and baffles
Installing sound-insulated walls and floors
Incorporating sound-absorbing materials in the interior finishing and furnishings, such as carpeting and upholstered furniture
Applies spatial planning to manage noise levels and minimize sound pollution. Strategic layout to separate quiet and noisy areas
Case Study: The Bloomberg European Headquarters in London incorporates acoustic baffles, soundproofing materials, and intelligent layout design to control reverberation and ambient noise, contributing to its BREEAM “Outstanding” rating.
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| Bloomberg European Headquarters, London |
FINAL THOUGHTS
Indoor
Environmental Quality (IEQ) stands at the forefront of sustainable
building design, significantly influencing both our physical
well-being and cognitive abilities. By emphasizing clean air,
non-toxic materials, effective sound control, and overall comfort,
green buildings not only contribute to environmental preservation but
also enrich the human experience. As the demand for healthier living
and working environments continues to rise, prioritizing IEQ will
drive groundbreaking advancements in sustainable architecture, making
our spaces not just livable but truly thriving.
Ar. JOEY CASTANEDA
Sustainable Architecture
Link in account for architectural works.
Photo Attributions:
BedZED eco-village, London
By Tom Chance, <a href="https://creativecommons.org/licenses/by/2.0" title="Creative Commons Attribution 2.0">CC BY 2.0</a>, <a href="https://commons.wikimedia.org/w/index.php?curid=11884918">Link</a>
Phipps Conservatory in Pittsburgh
<ahref="https://commons.wikimedia.org/wiki/File:Phipps_Conservatory_%26_Botanical_Gardens_132.jpg">Daderot</a>, Public domain, via Wikimedia Commons
Bloomberg European Headquarters in London
<ahref="https://commons.wikimedia.org/wiki/File:Bloomberg_European_Headquarters,_London.jpg">DAVID HOLT</a>, <a href="https://creativecommons.org/licenses/by/2.0">CC BY 2.0</a>, via Wikimedia Commons
The Edge, Amsterdam (MrAronymous, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Bullitt Center, Seattle (Joe Mabel, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)