Build or Revive Slides Build or Revive
The Environmental Impact of Urban Development
Environmental Science Grades 10-12
The Big Question
Former Textile Mill: Abandoned for 15 years.
"The city wants to revitalize this neighborhood. You are on the planning commission."
Do we demolish it or fix it up?
What is the quickest path?
What is the cleanest path?
What is the cheapest path?
Planning Concepts
Greenfield
Undeveloped land, often rural or forest, being converted to urban use for the first time.
Brownfield
Previously used industrial or commercial land that may have environmental contamination.
Retrofitting
The process of modifying existing structures to improve energy efficiency or change their function.
Embodied Carbon
CO₂ emissions associated with materials and construction processes throughout the whole life cycle of a building.
Video Briefing
Sustainable Cities: Crash Course Geography #49
Segment: 7:05 - 8:16
Embedded media
Watch for the global impact of construction materials.
Listen for the percentage of greenhouse gas emissions from construction.
Compare the impacts of sprawl vs. reuse .
The Carbon Calculator
Project A: Greenfield
Build a "Passive House" certified apartment complex on a former wildflower meadow at the edge of town.
Max energy efficiency once built
Heavy use of new concrete/steel
Habitat loss for local pollinators
Project B: Retrofit
Convert an old brick warehouse downtown into loft apartments. Reusing existing foundation and walls.
Zero new habitat loss
Low embodied carbon (reuse walls)
Harder to reach max efficiency
Open your Case Study Handouts!
Local Lens
Find one building in our city that has been adaptively reused . What was it originally? What is it now? Why do you think they chose to retrofit instead of rebuild?
Be ready to share your findings next class!
Build vs Revive Handout Case Study: Operation Warehouse Rescue
Urban Development Comparative Analysis
Environmental Science
The city of Riverton has 10 acres of land available for a new 100-unit housing development. Two competing firms have submitted proposals. As an Environmental Planner, you must analyze the ecological and carbon footprint of each approach.
Proposal A: Meadow View
Greenfield Development
Location: A pristine 10-acre wildflower meadow on the city's outskirts.
Project Specs:
New "Smart" construction using recycled steel and low-carbon concrete.
Solar-integrated roofing (net-zero operational energy).
Requires 2 miles of new road and utility line extension.
<table class="w-full text-sm border-collapse"><tbody><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Embodied Carbon:</td><td class="py-2 text-right font-mono text-red-600">5,500 tons CO₂e</td></tr><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Habitat Impact:</td><td class="py-2 text-right font-mono text-red-600">100% loss (10 acres)</td></tr><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Operational Energy:</td><td class="py-2 text-right font-mono text-emerald-600">Level: A+ (Net Zero)</td></tr><tr><td class="py-2 font-semibold text-slate-800">Waste Generated:</td><td class="py-2 text-right font-mono text-amber-600">80 tons (packaging/scrap)</td></tr></tbody></table>
Proposal B: The Foundry
Brownfield Retrofit
Location: A 3-acre abandoned industrial warehouse district downtown.
Project Specs:
Adaptive reuse of existing brick walls and heavy timber frame.
Upgraded with double-pane windows and high-efficiency HVAC.
Direct access to existing subway and city sewage/power lines.
<table class="w-full text-sm border-collapse"><tbody><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Embodied Carbon:</td><td class="py-2 text-right font-mono text-emerald-600">1,200 tons CO₂e</td></tr><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Habitat Impact:</td><td class="py-2 text-right font-mono text-emerald-600">0% loss (all concrete)</td></tr><tr class="border-b border-slate-100"><td class="py-2 font-semibold text-slate-800">Operational Energy:</td><td class="py-2 text-right font-mono text-amber-600">Level: B- (High efficiency)</td></tr><tr><td class="py-2 font-semibold text-slate-800">Waste Generated:</td><td class="py-2 text-right font-mono text-red-600">450 tons (demolition/gutting)</td></tr></tbody></table>
Understanding the Metrics
Embodied Carbon:
The "up-front" carbon debt. Includes mining, manufacturing, and transporting materials. It's estimated that construction materials alone cause 10% of global emissions.
Carbon Counter Worksheet Carbon Counter Worksheet
Student Name
Date
ENVS-302 // URBAN DESIGN
1 Initial Reflection
Look at the image of the abandoned factory on the screen. What are three environmental hazards or opportunities you notice just from looking at the structure?
2 Video Insight: Sustainable Cities [7:05-8:16]
Why is the building/construction industry so important for climate change goals?
Define "Retrofitting" in your own words based on the video:
3 Comparative Analysis: Meadow View vs. The Foundry
Use the "Case Study Handout" to complete the following evaluation.
Metric Greenfield (A) Retrofit (B) Which is better for the environment? Embodied Carbon Habitat Impact Daily Energy Use Waste & Refuse
The "Carbon Debt" Problem:
Retrofit (B) has 4,300 tons less embodied carbon, but Greenfield (A) is more efficient every day. If Greenfield saves 100 tons of CO2 per year compared to the Retrofit, how many years does it take for the Greenfield to "break even" and become the cleaner choice?
______ years
(Embodied Carbon Difference ÷ Annual Efficiency Savings)
The Biodiversity Loss:
Describe one ecosystem service that is lost when building on the Greenfield (wildflower meadow) that is not an issue for the Brownfield retrofit.
Planning Commission Final Vote
Based on your analysis, which project should the city approve? Provide two scientific justifications based on the carbon/ecological data you calculated.
Project A
Project B
Urban Planning Teacher Guide Urban Planning Teacher Guide
Lesson: Build or Revive
Teacher Resource
Learning Objectives
Differentiate between Greenfield and Brownfield development.
Analyze the impact of embodied carbon versus operational energy efficiency.
Evaluate the trade-offs in urban planning regarding biodiversity and waste.
Pacing Guide
Hook (Abandoned Factory) 5 minutes
Viewing (Crash Course #49) 10 minutes
Case Study Analysis 20 minutes
Class Debate/Final Vote 10 minutes
Vocabulary Check
Embodied Carbon
The CO2 emitted during material extraction, manufacture, and transport. This is the "sunk cost" of a building.
Adaptive Reuse
Taking an old structure and using it for a purpose other than it was originally intended (e.g., factory to lofts).
Worksheet Answer Key & Facilitation Tips
Part 2: Video Insights
Industry Importance: Construction is responsible for ~10% of global greenhouse gas emissions (early 2020s data). Reducing new builds reduces this "upfront" carbon.
Retrofitting: Reusing what's already there; modifying existing buildings to meet new safety/efficiency standards rather than demolishing.
Part 3: The Carbon Calculator
Metric Comparison Result Embodied Carbon Retrofit is better (1,200 vs 5,500 tons) Habitat Impact Retrofit is better (0% vs 100% loss) Daily Energy Greenfield is better (Net Zero vs B-) Waste Greenfield is better (80 vs 450 tons)
Break-Even Math: (5,500 - 1,200) / 100 = 43 years .
Critical Thinking Questions
Gentrification: If the warehouse becomes "luxury lofts," where do the people who lived in the neighborhood go? (Connects to [4:16] in the video).The Gray-Green Divide: How could we add green space to Project B (The Foundry) to help with the Urban Heat Island effect? (e.g., green roofs, pocket parks).
