Comprehensive Overview of Sustainable Materials for Construction

642 Words

MATERIALS FOR SUSTAINABLE SITES / GREEN MATERIALS

Overview

This document discusses the fundamental concepts of sustainable construction materials, emphasizing the need to transition from traditional practices to more environmentally conscious approaches. It highlights the impacts of construction materials on the ecosystem and outlines various criteria for selecting materials that align with sustainable development goals.

Background

Historically, the construction industry has undergone significant transformations, notably in the 20th century. Key trends included:

  • A move from localized material usage to large-scale centralized production and global distribution.

  • An increase in reliance on cheap labor instead of skilled artisans.

  • The development of national standards that often overlook regional materials and localized conditions.

  • The availability of inexpensive resources that do not account for the ecological costs of their extraction and use.

In contemporary practices, there are critical environmental concerns that construction materials must address, including:

  • Ecological destruction

  • Air pollution

  • Climate change

  • Loss of biodiversity

  • Rising fuel costs

Shifting Towards Sustainability

The construction industry is urged to adopt a sustainable approach by:

  • Transitioning from non-renewable to renewable resources

  • Shifting from waste production to reuse and recycling

  • Considering life-cycle costs rather than just initial costs

  • Incorporating full-cost accounting, encompassing waste, emissions, and pollution

Life Cycle of Materials

Understanding the life cycle of construction materials is vital. The typical phases include:

  1. Extraction of raw materials

  2. Manufacturing

  3. Transportation

  4. Installation

  5. Usage

  6. Disposal, which may include recycling or repurposing

At each phase, energy input and waste output are critical factors that influence the overall sustainability of the material.

Criteria for Choosing Sustainable Materials

1. Resource Efficiency

When selecting materials, focus on:

  • Minimal material use

  • Reused and reprocessed materials

  • Post-consumer and pre-consumer recycled-content materials

  • Products from renewable sources (e.g., agricultural byproducts)

  • Materials with potential for reuse and recycling

2. Minimizing Embodied Energy and Carbon

It is essential to choose materials that:

  • Are sustainably harvested or mined

  • Undergo minimal processing

  • Generate low pollution during their entire life cycle

  • Utilize renewable energy sources in manufacturing

Embodied energy and carbon measurements are crucial. For instance, common units like MJ/kg (megajoules per kilogram) and tCO2 (tonnes of carbon dioxide) provide insights into the environmental impact of materials.

3. Avoiding Harmful Materials

Construction materials should:

  • Be low or non-toxic to avoid health risks

  • Avoid volatile organic compounds (VOCs) that can compromise indoor air quality

  • Use non-toxic chemicals throughout their life cycle

4. Supporting Sustainable Design

Materials should contribute positively to site sustainability by:

  • Improving hydrological health and reducing stormwater runoff

  • Lessening the urban heat island effect

  • Reducing energy and water consumption in site operations

Benefits of Sustainable Material Selection

The adoption of sustainable materials leads to many benefits such as:

  • Lower maintenance and replacement costs

  • Energy conservation

  • Improved health and productivity for occupants

  • Greater design flexibility

Avoiding Greenwashing

Consumers must be vigilant against claims that may be misleading. Recognizing genuine green products includes:

  • Examining labels for reliable environmental attributes

  • Understanding the difference between "recycled" and "recyclable" products

  • Researching green certifications and product origins

  • Evaluating transport-related emissions to determine true sustainability

Evaluating Materials and Products

Utilizing methods like Life Cycle Assessment (LCA), Sustainability Assessment (SA), and Embodied Energy Analysis provides a thorough evaluation of construction materials.

Sustainable Options in Construction Materials

Various common materials have sustainable alternatives. Examples include:

  • Concrete: Pervious concrete allows stormwater to permeate, supporting effective drainage.

  • Brick Masonry: Green Leaf Brick made from 100% recycled materials.

  • Aggregates and Stone: Sustainable extraction practices that enhance environmental recovery.

  • Wood Products: Sustainably sourced options such as cedar, known for its resistance and low environmental impact.

  • Metals: High recycled content and excellent recyclability contribute to overall building sustainability.

Conclusion

Choosing sustainable materials involves careful consideration of several factors, including toxicity, recyclability, labor implications, energy efficiency, and local sourcing. These factors collectively contribute to the environmental integrity of construction projects.

References

Key sources include Meg Calkins’ 2009 work, "Materials for Sustainable Sites" and various online resources detailing the embodied energy of materials.