Life Cycle Building Energy: Before, During and After 6 April 2017 Passive House Northwest Conference
ISO and the 14040 series ISO makes voluntary standards to support international trade: ISO is sister organization of WTO 14040 series are guidance on how to do LCA s 14020 series are guidance on ecolabels ISO 21930 EPDs for Construction Products Regulation & legislation based on LCA is presumed not to present technical barriers to trade under the WTO
Systems Analysis; Input output Step 1: Life Cycle Inventory Raw Material Extraction Inputs (resources) energy, materials Manufacturing, Production Distribution, Transportation Operations and Maintenance Outputs air and water emissions, wastes Recycle and Waste Management Industrial System The science of measuring the environmental performance of products & services
Raw Materials Extraction
Manufacturing
Transport
Use & Maintenance Where the system function happens
Disposal West Point Treatment Plant, Seattle Tacoma Landfill Recycling, Bullitt Building
Flow chart for windows Raw Material Extraction Iron Ore Timber NaCl Metal & Catalyst Ores sand Materials Production Lumber Steel Resins Glass Paper & Cardboard Component Production Dimensional Lumber Fasteners Dimensional Glass Coatings Transport and Waste Management Building End of life Manufacturing Capital Goods Personnel Impacts limestone soda Petroleum Natural Gas Coal Renewable Energy Fiberglass Aluminum Energy Production Electricity Fuels Packaging Glue Window Assembly Window Installation Operation in Building Insulation & Transmission Cleaning Replacement Data Source Key Primary Secondary Tertiary System Boundary
Inventory of a unit process Ecosphere flows measured through environmental analyses Flows to and from Flows to and from Unit Process the Ecosphere Elementary flows the Technosphere System model Technosphere flows measured through purchases and sales
Indicators for LCA Impact Categories Eutrophication Ecoprofile Science based Comprehensive Transparent
System Function & Functional Unit Only unique part of LCA Connects social benefits (goods and services) to environmental impacts Typically expressed as utility x amount x time For example: an internal paint covers a square meter for 10 years (meeting the relevant ASTM standard) Copyright: <a href='https://www.123rf.com/profile_alessandroguerriero'>alessandroguerriero / 123RF Stock Photo</a>
A Building Has a Lifetime Commercial Buildings 70 75 years median Residential Buildings 30 200 years Before demolition
Lifetime of Building Components (years) Slate roof 40-100 Wood shingle roof 15-25 Asphalt roof 15-30 Tile roof 50 Metal roof 20-50 Masonry chimney and fireplace 100 Drywall and plaster 65-70 Paint (interior and exterior) 5-10 Vinyl sheet or tile 20-30 Ceramic tile 100 Laminate 15 Oak or pine floor 100 Carpet 10 Wood siding 20 to life of building Vinyl siding 50 Aluminum siding 25-50 Brick or stucco Life of building Brick or concrete patio 25-30 Wood deck 10-15 Asphalt driveway 10-20 Treated lumber 30-40 Kitchen cabinets 15-20 Gutters 25-30 Does the product use lots of energy in extraction, production or transport? Red marked items have high embodied energy.
What this means for the building LCA calculations If the building will last for 60 years The asphalt shingle roof will be multiplied 2 to 3 times (depending on quality) The slate roof be counted once Laminate floors will be multiplied three times Solid wood floors will be counted once All the impacts of the replacement production and installation will be calculated and included in the building LCA DURABLE PRODUCTS TEND TO PROVIDE LOWER IMPACTS, EVEN IF THE EMBODIED ENERGY IS HIGHER
http://thegreenestbuilding.org/
Residential Energy Expenditures Operations 80% Embodied 20% Demolition 0% 2000 sq.ft. single residence, data from EIA & thegreenestbuilding.org
Almost 40% of US total energy is used in homes
Almost 40% of US total energy is used in homes Includes: small electric devices, heating elements, exterior lights, outdoor grills, pool and spa heaters, backup electricity generators, and motors not listed above. Does not include electric vehicle charging
Environmental Impacts Categories Energy Use Climate Change Eutrophication Photochemical Smog Acidification Human Toxicity Eco Toxicity Fossil Fuel Depletion
US Electricity Flow 2015 (EIA) quadrillion BTU Only 33.9% of energy is end used; in 2011 it was only 32.8%: rest is losses or plant use
Life Cycle Carbon Footprints and Data of Electricity Energy Source Grams CO 2 % of electric $/MWh Equivalents/kWh grid, 2015 EIA 2018 Coal 1250 1350 37 115.8 Natural Gas 400 500 27 72.6 Nuclear 10 20 21 95.2 Hydro 1 5 6 83.5 Wind 5 50 3 73.6 Solar 10 100 1 114.3
Energy Efficiency Measures 700,000 600,000 Annual Energy Use (kwh) 500,000 400,000 300,000 200,000 Net Zero SOLAR DOMEST HOT WTR ELEVATOR VENT FANS PUMPS & AUX SPACE COOLING SPACE HEATING MISC EQUIP 100,000 IT SERVER 0 LIGHTS Data from Bullitt Building, Seattle
Conclusions LCA is a good tool to evaluate energy in buildings Energy efficiency has increased over the past decade, but not energy use: residences use a LOT of the total US energy (almost 40%) Embodied energy is typically relatively small As use phase energy goes down, the relative importance of embodied energy rises Space heating and cooling is a shrinking fraction of the energy use of residences: plug loads are rising There is a tradeoff between durability and embodied energy Passive solar is a GREAT idea. Active solar is even better
Thank you for your kind attention Rita Schenck rita@iere.org