# Sustainable Material Selection ## Table of Contents - [[#Overview]] - [[#Principles of Sustainable Material Selection]] - [[#Environmental Product Declarations EPDs]] - [[#Health Product Declarations HPDs]] - [[#Declare Labels]] - [[#Material Transparency and Disclosure]] - [[#The Living Building Challenge Red List]] - [[#Bio-Based Materials]] - [[#Recycled and Reclaimed Content]] - [[#Design for Disassembly]] - [[#Material Passports]] - [[#Green Building Rating System Credits]] - [[#LEED Material Credits]] - [[#BREEAM Material Credits]] - [[#Practical Notes for Architects]] - [[#References and Standards]] --- ## Overview Sustainable material selection is the process of specifying building products that minimise environmental harm, protect human health, and support circular economy principles across the entire material life cycle. For architects, material choices directly influence embodied carbon, indoor environmental quality, resource depletion, and waste generation. The growing availability of transparency tools (EPDs, HPDs, Declare labels) enables evidence-based material specification that moves beyond marketing claims to verified performance data. See [[Operational vs Embodied Carbon]] for the broader context of material impacts within whole-life carbon assessment. --- ## Principles of Sustainable Material Selection Sustainable material selection is guided by the following hierarchy: 1. **Avoid**: Question the need for the material entirely (reduce material use through design efficiency). 2. **Reduce**: Minimise quantities through structural optimisation and modular coordination. 3. **Reuse**: Specify reclaimed materials and components (salvaged timber, reclaimed brick, reused steel). 4. **Select low-impact**: Choose materials with low embodied carbon, low toxicity, and responsible sourcing. 5. **Design for longevity**: Specify durable materials appropriate to their exposure and function. 6. **Design for circularity**: Enable future disassembly, reuse, and recycling. --- ## Environmental Product Declarations EPDs EPDs are standardised, third-party verified documents reporting the environmental impacts of a product across its life cycle. ### Structure and Content - Governed by EN 15804+A2 (construction products) and ISO 14025 (general). - Report environmental indicators including: - **GWP** (Global Warming Potential, kgCO₂e) - **ODP** (Ozone Depletion Potential) - **AP** (Acidification Potential) - **EP** (Eutrophication Potential) - **ADPF** (Abiotic Depletion Potential — fossil fuels) - **ADPE** (Abiotic Depletion Potential — elements) - Declared unit: Functional or declared unit (e.g., 1 m² of wall panel, 1 tonne of concrete). - System boundary: Cradle-to-gate (A1–A3), cradle-to-gate with options (A1–A3 + C + D), or cradle-to-grave (A1–C4). ### Types of EPDs | Type | Scope | |------------------------|------------------------------------------| | Product-specific EPD | Single product from a single manufacturer | | Industry-average EPD | Average of products within a category | | Sector EPD | Representative of a product group | Product-specific EPDs are preferred for accurate carbon assessment. Industry-average EPDs serve as default values when specific data is unavailable. ### EPD Programme Operators Major EPD programme operators include: EPD International (Sweden), IBU (Germany), BRE Global (UK), ASTM International / NSF (North America), and the Australasian EPD Programme. --- ## Health Product Declarations HPDs HPDs disclose the chemical composition of building products and screen ingredients against health hazard lists: - Governed by the HPD Open Standard (currently v2.3). - Reports: product contents by weight percentage, associated health hazards (GreenScreen, IARC, EU CLP), and residuals of concern. - **Nested format**: Manufacturer discloses hazard information hierarchically. - HPDs do not make health claims; they provide transparency for specifiers to make informed decisions. - Complementary to EPDs: EPDs address environmental impact; HPDs address health impact. --- ## Declare Labels Declare is a transparency platform developed by the International Living Future Institute (ILFI): - Products are listed with their ingredients, sourcing, and end-of-life options. - **Declare label statuses**: - **Red List Free**: Contains no Red List chemicals (highest tier). - **Declared**: Fully transparent but may contain Red List chemicals. - **Red List Approved**: Contains Red List chemicals but has received an approved exception. - Declare labels are required for Living Building Challenge certification and earn credits under LEED v4.1. - The Declare database is publicly searchable, providing architects with a vetted product library. --- ## Material Transparency and Disclosure Material transparency encompasses the broader movement towards full disclosure of product composition and impacts: - **Transparency catalogue**: Searchable databases of products with EPDs, HPDs, and Declare labels (e.g., mindful MATERIALS, Portico). - **Material health certificates**: Cradle to Cradle Certified Material Health certificates assess material chemistry. - **Optimization reporting**: Some manufacturers publish Environmental Product Optimization reports showing improvement trajectories. Architects should establish transparency requirements in the project specification, requiring minimum disclosure levels for specified products. --- ## The Living Building Challenge Red List The Red List identifies the worst-in-class chemicals and materials prevalent in the building industry: **Key Red List chemicals include**: - Asbestos - Cadmium - Chloroprene (neoprene) - Chlorinated polyethylene and chlorosulfonated polyethylene - Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) - Formaldehyde (added) - Halogenated flame retardants - Lead (added) - Mercury - Perfluorinated compounds (PFAS) - Phthalates (all classifications) - Polyvinyl chloride (PVC) - Volatile organic compounds in wet-applied products above specified limits - Wood treatments containing creosote, arsenic, or pentachlorophenol The Red List is regularly updated. Temporary exceptions exist where no viable alternatives are available. --- ## Bio-Based Materials Bio-based materials sequester atmospheric carbon during growth, offering potential carbon benefits: - **Structural timber**: Glulam, CLT, and LVL as alternatives to steel and concrete framing. Biogenic carbon storage ranges from 1.5–1.8 kgCO₂/kg of timber. - **Natural insulation**: Wood fibre, hemp-lime (hempcrete), sheep's wool, cellulose (recycled paper), straw bale, and cork. - **Bio-based composites**: Bamboo panels, mycelium-based materials, bio-resins. - **Natural finishes**: Lime plaster, clay plaster, natural stone, linoleum (linseed oil based). **Important consideration**: Biogenic carbon accounting varies between standards. EN 15804+A2 requires separate reporting of biogenic carbon (module A = storage, module C = release). Specify bio-based materials from sustainably managed sources (FSC or PEFC certified). --- ## Recycled and Reclaimed Content ### Recycled Content - **Pre-consumer** (post-industrial): Manufacturing waste diverted from the waste stream and reprocessed. - **Post-consumer**: Products recovered after consumer use and reprocessed into new products. - Post-consumer recycled content is generally considered more beneficial as it diverts material from landfill. - Common recycled content materials: recycled steel (EAF production, typically 85–95% recycled), recycled aggregate concrete (up to 30% RA), recycled aluminium, recycled glass, recycled plastic products. ### Reclaimed Materials - Reclaimed (salvaged) materials are reused with minimal reprocessing: reclaimed timber, reclaimed brick, reclaimed stone, reclaimed steel. - Reclaimed materials reduce embodied carbon to near zero (only transport and minor processing). - Structural reclaimed materials require testing and certification for design use. - Sources: architectural salvage yards, demolition audits, material exchange platforms (e.g., Enviromate, Rotor DC). --- ## Design for Disassembly Design for Disassembly (DfD) enables buildings and components to be taken apart at end of life for reuse or recycling: **Key DfD principles**: - Use mechanical fixings (bolts, screws, clips) rather than adhesives or welded connections. - Use reversible connections that can be unloaded without damage. - Separate building layers (structure, envelope, services, finishes) for independent replacement. - Standardise component sizes for reuse compatibility. - Document material specifications and connection details for future deconstruction. - Avoid composite materials that cannot be separated for recycling. - Create a deconstruction plan and material schedule as part of the design documentation. --- ## Material Passports Material passports are digital documents recording the characteristics, quantities, and location of materials in a building: - Enable buildings to serve as "material banks" for future resource recovery. - Record: material type, manufacturer, EPD data, location in building, connection method, expected service life, recyclability, and hazardous content. - Platforms: Madaster, Buildings as Material Banks (BAMB), and proprietary BIM-integrated systems. - Material passports support circular economy objectives and inform future renovation and demolition decisions. - Integration with BIM (IFC format) enables automated material passport generation from design models. --- ## Green Building Rating System Credits ### LEED Material Credits Under [[LEED Certification System]] v4.1: | Credit | Points | Requirement | |--------------------------------------------|--------|--------------------------------------------------------| | Building Life-Cycle Impact Reduction | 5 | Whole-building LCA or building reuse | | Environmental Product Declarations | 2 | 20 products with EPDs | | Sourcing of Raw Materials | 2 | Recycled content, bio-based, responsibly sourced | | Material Ingredients | 2 | HPDs, Declare labels, or Cradle to Cradle | | Construction and Demolition Waste Management| 2 | 50–75% diversion from landfill | ### BREEAM Material Credits Under [[BREEAM Rating System]] New Construction: | Issue | Title | Credits | Requirement | |---------|-------------------------------|---------|------------------------------------------------| | Mat 01 | Environmental impacts of materials | 6 | Life cycle assessment per EN 15978 | | Mat 02 | Hard landscaping and boundary | 1 | Environmental impact of external materials | | Mat 03 | Responsible sourcing | 4 | BES 6001, FSC, PEFC certification | | Mat 05 | Designing for durability | 1 | Protection of vulnerable building elements | | Mat 06 | Material efficiency | 1 | Quantified material efficiency measures | --- ## Practical Notes for Architects - Include EPD, HPD, and Declare label requirements in Division 01 of the project specification. - Establish embodied carbon budgets per building element at RIBA Stage 2 (see [[Operational vs Embodied Carbon]]). - Use tools such as One Click LCA, Tally, or EC3 for comparative material carbon analysis. - For LEED projects, track material documentation (EPDs, HPDs, recycled content certificates) from procurement through construction. - Specify concrete with minimum 50% GGBS or 30% PFA replacement to reduce cement content. - Require structural steel suppliers to declare recycled content percentage and provide EPDs. - Investigate local material sources to reduce transport emissions (Module A4). - Consider whole-life replacement cycles: a product with higher upfront carbon but longer service life may have lower whole-life carbon than a low-carbon alternative requiring frequent replacement. - Produce a DfD strategy document for all new buildings to future-proof for circular material recovery. --- ## References and Standards - EN 15804+A2: Sustainability of Construction Works — Environmental Product Declarations - ISO 14025: Environmental Labels and Declarations — Type III Environmental Declarations - ISO 21930: Sustainability in Buildings and Civil Engineering Works — Environmental Declaration of Building Products - HPD Collaborative, *HPD Open Standard v2.3* - ILFI, *Living Building Challenge 4.0* and *Declare Programme* - WRAP, *Designing for Deconstruction* guidance - [[Operational vs Embodied Carbon]] - [[LEED Certification System]] - [[BREEAM Rating System]] --- #sustainability #materials #EPD #HPD #embodiedcarbon #circularity