LEED Core Concepts S4

Building construction generates large amounts of solid waste, which can lead to:

• Greenhouse gas emissions from transportation and methane production in landfills.
• Carbon dioxide emissions from waste incineration.
• The need for improved recycling rates to reduce overall emissions, as current recycling rates are around 32%, equivalent to removing almost 40 million cars from the road.

Improving recycling rates from 32% to 35% could result in significant environmental benefits, including savings equivalent to more than 5 million metric tons of carbon dioxide emissions, contributing to a reduction in greenhouse gas emissions associated with waste disposal.

When specifying green custodial products, choose those that:

• Meet Green Seal, Environmental Choice, or EPA standards.
• Protect indoor environmental quality.
• Reduce environmental damage through sustainable formulations and practices.

The major categories associated with the LEED rating systems include:

A building's location can:

• Meet the needs of the local community
• Support active street life
• Promote healthy lifestyles
• Reduce greenhouse gas emissions by facilitating public transportation, biking, and walking.

Teams can start a sustainable design project by:

1. Selecting a site and determining the best functions and uses for that location.
2. Identifying a function and finding the most suitable location for that land use.

When selecting a location, consider:

• Previous development of the site
• Connection to local infrastructure and public transportation
• Nature of street life and community contribution
• Travel patterns of local residents and workers

Smart growth emphasizes:

• Development that improves the triple bottom line
• Protecting open space and farmland
• Proximity of housing, jobs, and services to each other

Infill development utilizes sites in previously developed areas, filling spaces between existing structures. It helps limit land covered by buildings and makes more efficient use of space within communities.

Brownfield sites are lands where development may be complicated by hazardous substances or pollutants. They provide opportunities for green building projects to improve environmental performance through redevelopment and cleanup efforts.

Developing on greenfield sites increases the regional development footprint, reduces land available for open space or agriculture, and fragments wildlife habitat, encouraging sprawl outside built-up areas.

Strategies include:

1. Choose redevelopment and infill development.
2. Locate near existing infrastructure.
3. Protect habitat by avoiding sensitive sites.
4. Increase density to maximize space usage.
5. Increase diversity of uses to meet community needs.
6. Encourage multiple modes of transportation for accessibility.

Transportation accounted for 33% of total U.S. greenhouse gas emissions in 2008, highlighting its significant impact on environmental sustainability.

Promoting alternative transportation benefits both building occupants and developers by:

• Reducing transportation effects through access to alternative modes.
• Encouraging walking and bicycling.
• Providing fueling facilities for alternative-fuel vehicles.
• Rewarding project teams for reducing automobile trips by locating in high-density areas or near mass transit.

Strategies to address transportation in design and planning include:

1. Locate near public transit: Select a project site within easy walking distance of an existing transportation network.
2. Limit parking: Reduce the number of parking spaces to encourage alternative transportation options.
3. Encourage bicycling: Install secure bike racks and showers for commuters.

Strategies to address transportation in operations and maintenance include:

1. Encourage carpooling: Designate preferred spaces for carpool vehicles in the parking area.
2. Promote alternative-fuel vehicles: Provide a convenient refueling station on the site.
3. Offer incentives: Develop an alternative commuting incentive program for building occupants.
4. Support alternative transportation: Promote alternatives to single-occupant car commuting at the building and/or city level.

Land use decisions can impact transportation and greenhouse gas emissions by:

• Reducing the length and frequency of vehicle trips.
• Encouraging shifts to more sustainable modes of transportation.
• Poor planning can lead to increased greenhouse gas emissions, even with investments in technology and alternative energy.

Key strategies include:

1. Building Frontage: Ensure buildings are close to the street to create an engaging environment.
2. Ground-Level Façade: Design facades that are inviting and accessible to pedestrians.
3. Building Height-to-Street-Width Ratio: Maintain a ratio that enhances the pedestrian experience.
4. Sidewalks: Provide wide, well-maintained sidewalks.
5. Limit Street Speeds: Implement measures to reduce vehicle speeds for pedestrian safety.

Neighborhoods can promote connectivity by:

1. Limiting Culs-de-Sac: Reduce the number of dead-end streets to enhance movement.
2. Prohibiting Gated Communities: Ensure open access to all areas of the neighborhood.
3. Using a Street Grid Pattern: Implement a grid layout to facilitate easier navigation and access.

Providing diverse land uses is important because it:

• Enhances Accessibility: Residents can meet their daily needs within walking distance.
• Supports Local Economy: A mix of shops, restaurants, and services fosters economic activity.
• Encourages Community Interaction: Diverse spaces promote social interactions among residents.
• Improves Quality of Life: Access to various amenities contributes to overall well-being.

Strategies to support access to sustainable food include:

• Community Gardens: Encourage local food production and community involvement.
• Farmers Markets: Provide a venue for local farmers to sell fresh produce.
• Urban Farms: Utilize vacant land for agricultural purposes.
• Community-Supported Agriculture Programs: Connect residents with local farms for fresh food delivery.

Neighborhoods can ensure easy access to grocery stores by:

• Strategically Locating Stores: Place grocery stores within walking distance of residential areas.
• Providing a Variety of Food Choices: Include options beyond fast food to promote healthy eating.
• Incorporating Transportation Options: Ensure public transport routes connect residents to grocery stores.

Key considerations include:

1. Adequate open space surrounding the project.
2. Understanding the local climate.
3. Previous development of the site.
4. Species in the area that may use the site as habitat.

Good site design contributes by:

• Providing ecosystem services.
• Creating a sense of place.
• Helping projects adapt to climate change.
• Integrating the building and grounds into the local ecosystem.

Broad goals include:

• Reducing environmental impacts of landscaping.
• Minimizing maintenance costs.
• Contributing to the restoration and regeneration of the area.

LEED rating systems address topics such as:

• Site design and management
• Rainwater management
• Heat island effect

Selecting native and adapted species can:

• Thrive without irrigation, pesticides, or fertilizers.
• Enhance soil nutrients, supporting regenerative project goals.
• Deter pests naturally.
• Minimize evapotranspiration, which is crucial in arid climates.
• Create wildlife habitat and support integrated pest management (IPM).

Hardscape can be minimized by:

1. Substituting pervious surfaces for traditional paving.
2. Using pervious paving systems for parking lots, walkways, and decorative areas.
3. Allowing rainwater infiltration to reduce heat island effects.

To prevent light pollution, strategies include:

• Avoiding up-lighting and glare.
• Using shielded fixtures.
• Implementing strategic lighting design to reduce light trespass and improve site safety.

Key strategies include:

• Minimize Hardscape: Substitute pervious surfaces for traditional paving.
• Use Native Landscaping: Select native plants to reduce water use and provide habitat.
• Prevent Light Pollution: Use shielded fixtures and strategic lighting design.
• Preserve Open Space: Protect and restore natural vegetation and sensitive areas.
• Protect and Restore Habitat: Designate protected areas and develop a conservation management program.

A sustainable site management plan should address:

1. Application of chemicals
2. Cleaning of hardscape and building exterior
3. Integrated pest management program

Conservation programs can be effectively implemented by:

• Collaborating with ecologists
• Partnering with nonprofit organizations to protect species and habitat

To maintain site lighting and prevent light pollution, it is important to:

1. Replace fixtures according to the original design
2. Use timers to shut off lights automatically after hours if higher light levels are needed

Impervious surfaces, such as asphalt and concrete, lead to:

• Prevented percolation and infiltration
• Increased water runoff
• Soil erosion and sedimentation of local waterways
• Nonpoint source pollution that degrades surface water quality and harms aquatic life

Common strategies for managing rainwater include:

• Minimizing impervious surfaces
• Protecting soils
• Enhancing native vegetation
• Using low-impact development (LID) and Green Infrastructure (GI) approaches

The five components of LID control measures are:

1. Site planning
2. Hydrologic analysis
3. Integrative management practices
4. Erosion and sediment control
5. Public outreach

Collected rainwater can be reused for landscape irrigation, toilet and urinal flushing, and custodial uses.

Increase the area of permeable surfaces, such as vegetated roofs, porous pavement, and landscaped areas.

Install dry ponds, rain gardens, bioswales, and similar landscape features designed to hold water and slow the rate of runoff.

The heat island effect refers to cities being warmer than nearby rural areas due to heat-absorbing surfaces, leading to increased air-conditioning use, higher energy demand, and declines in wildlife species not adapted to higher temperatures.

Direct runoff into rain gardens, bioswales, and other landscape features that retain water.

It helps in selecting appropriate rainwater management strategies, as conditions vary by region, such as on-site water collection being encouraged in the eastern U.S. but prohibited in some western states due to water laws.

Late afternoon temperatures vary by land use:

• Rural areas start near 30°C.
• Suburban Residential areas see a rise in temperature.
• Commercial areas maintain a constant temperature.
• Downtown areas peak above 33°C.
• Urban Residential areas experience a drop in temperature.
• Parks see a rise again, followed by a decrease in Suburban Residential and Rural Farmland back to around 30°C.

Strategies for reducing the heat island effect include:

1. Install reflective roof surfaces: Light-colored roofs absorb less heat.
2. Reduce the area of paved surfaces exposed to sunlight: Limit hardscape, design narrow roads, use light-colored paving, shade hardscape with greenery, and locate parking underground.
3. Plant an urban forest or a green roof: Use street trees, shrubs, and landscaping to reduce heat through evapotranspiration and provide shade.

Approximately 12% of total water use in the U.S. is accounted for by the operation of buildings, including landscaping.

Green building encourages innovative water-saving strategies such as:

• Assessing existing water resources
• Identifying opportunities for reducing water demand
• Exploring alternative water supplies
• Reusing wastewater and rainwater runoff for nonpotable functions

Guiding questions for a project team may include:

1. How much rain falls on the site per year?
2. How will water be used on site, and how can the amount be reduced?
3. What are the sources of graywater, such as from sinks and showers, that could be collected and reused for nonpotable uses, such as irrigation?

The water balance approach involves determining water usage based on a site's annual precipitation. It benefits projects with high rainfall by reducing the need for irrigation, making it easier to achieve water conservation goals.

Strategies to reduce indoor water use include:

1. Installing water-efficient fittings and fixtures.
2. Using nonpotable water for flush functions.
3. Installing submeters to track and log water use trends.
4. Selecting efficient cooling towers, chillers, and boilers.
5. Substituting harvested rainwater and nonpotable water for certain applications.

A water end-use profile helps project teams identify the largest users of water within a building, such as HVAC systems, restrooms, and landscaping. This information allows teams to evaluate the cost-effectiveness of specific conservation strategies tailored to the building's needs.

The 'efficiency first' approach to water conservation emphasizes:

1. Using water efficiently to reduce potable water use.
2. Considering the use of nonpotable water and alternative sources afterward.

This approach is rewarded by LEED for projects that reduce demand and reuse water for indoor and outdoor uses.

Submeters play a crucial role in water conservation by:

• Tracking and logging water use trends.
• Checking fixture performance.
• Identifying leaks or inefficiencies.
• Metering water lost to evaporation during cooling tower operation, providing important data for conservation efforts.

High-efficiency lavatories, kitchen sinks, showers, dual-flush toilets, waterless urinals, and composting toilets. These fixtures use less water than specified by the Energy Policy Act (EPAct) of 1992. It's recommended to select EPA WaterSense and ENERGY STAR products.

Using nonpotable water, such as captured rainwater or graywater, can significantly reduce indoor water use for flush fixtures. However, it's important to check local regulations as graywater use may not be permitted in all municipalities.

Submeters can meter indoor water systems, allowing for monitoring of data to track consumption trends, determine fixture performance, and pinpoint leaks.

1. Choose locally adapted plants that require less water.
2. Use xeriscaping principles with drought-tolerant plants.
3. Select efficient irrigation technologies like drip and bubbler systems.
4. Use nonpotable water for irrigation.
5. Install submeters to track water consumption and identify leaks.

Xeriscaping involves using drought-tolerant native or adapted plants along with landscape elements like rocks and mulch. This approach significantly reduces the need for irrigation, especially in arid regions, thus contributing to water efficiency.

Weather-based irrigation controllers adjust watering schedules based on current weather conditions, which helps to conserve water by preventing over-irrigation.

Unsustainable energy supply and demand can lead to serious implications for household budgets, international relations, and overall economic stability.

LEED-certified commercial office buildings use 24% less energy than the national average, according to a study by the New Buildings Institute.

In the ENERGY STAR Portfolio Manager, a score of 50 represents average building performance.

Almost half of the buildings in the study achieved an ENERGY STAR Portfolio Manager score of 75 or above.

The key areas for improving energy efficiency include:

1. Energy demand
2. Energy efficiency
3. Renewable energy
4. Ongoing performance

Monitoring performance is important to ensure that green buildings maintain their efficiencies and achieve their full potential over time.

1. Establish Design and Energy Goals: Set targets and performance indicators at the project's outset and verify them periodically.

2. Size the Building Appropriately: Ensure the facility is not larger than necessary to avoid wasteful energy demand.

3. Use Free Energy: Orient the facility to take advantage of natural ventilation, solar energy, and daylight.

4. Insulate: Design the building envelope to efficiently insulate against heating and cooling losses.

Green buildings reduce energy demand by:

• Capturing natural energy sources like sunlight, wind, and geothermal potential.
• Supporting building configurations that minimize solar gain in summer and maximize it in winter.
• Designing adjacent buildings to shade and insulate each other.
• Incorporating passive strategies such as daylight, thermal mass, and natural ventilation to reduce reliance on artificial lighting, heating, and cooling.

The Montreal Protocol is significant because it banned the production of chlorofluorocarbon (CFC) refrigerants and is phasing out hydrochlorofluorocarbon (HCFC) refrigerants due to their ozone-depleting potential and contribution to climate change. This regulation encourages the use of refrigerants that balance concerns about ozone depletion and climate change in building systems.

To achieve LEED certification, new buildings must not use CFC-based refrigerants, and existing buildings must complete a total CFC phase-out before project completion. LEED awards points for projects that avoid refrigerants entirely or select those with acceptable trade-offs regarding ozone depletion and climate change.

1. Use Free Energy: Utilize the facility's orientation, shades, windows, and vents for natural ventilation, solar energy, and daylight.

2. Monitor Consumption: Implement energy monitoring and feedback systems to encourage occupants to reduce energy demand.

EPA's ENERGY STAR Portfolio Manager is a benchmarking system that evaluates building performance by allowing users to enter data on electricity and natural gas consumption, comparing it against similar buildings to gauge relative performance.

Demand response (DR) strategies encourage electricity customers to reduce usage during peak demand times. Benefits include:

• Optimizing supply-side energy generation and delivery systems.
• Avoiding the need for additional power generation facilities and infrastructure.
• Balancing the contribution of renewable energy sources by reducing demand when renewable generation is low.

Energy demand typically increases with building size; larger buildings consume more energy. The LEED for Homes rating system includes a point adjustment to account for this relationship, specifically for projects using the Energy and Atmosphere prescriptive path.

Energy efficiency refers to using less energy to accomplish the same amount of work, often measured by energy intensity metrics such as energy use per square foot and per capita.

Improving the building envelope can lead to a reduction in the size of HVAC systems or even eliminate them, resulting in lower initial capital costs and long-term operating costs.

The largest category of energy consumption in commercial buildings is Space Heating, accounting for 36% of total consumption.

The integrative process allows project teams to identify synergistic strategies that enhance energy efficiency, such as optimizing the building envelope to reduce HVAC needs.

1. Address the Envelope: Use appropriate insulation and high-performance glazing to minimize heat gain/loss.

2. Install High-Performance Mechanical Systems and Appliances: Evaluate life-cycle costs and invest in ENERGY STAR appliances to reduce plug load.

3. Use High-Efficiency Infrastructure: Implement efficient street lighting and LED traffic signals.

4. Capture Efficiencies of Scale: Design district heating and cooling systems for multiple buildings.

5. Use Energy Simulation: Employ computer modeling to identify energy efficiency opportunities.

6. Monitor and Verify Performance: Ensure building systems function as designed through control systems and commissioning.

Reduced demand and increased efficiency can make it cost-effective to meet a building's energy needs from renewable sources. Renewable energy includes solar, wind, wave, biomass, geothermal, and certain hydropower forms, avoiding environmental impacts associated with nonrenewable fuels. LEED distinguishes between renewable energy production and purchasing off-site green power or carbon offsets, with renewable energy production involving systems like solar panels that generate clean electricity.

LEED distinguishes renewable energy production as generating clean electricity (e.g., solar panels) from purchasing off-site green power, which is typically bought at a premium from utilities or renewable energy certificate (REC) providers. RECs are tradable commodities linked to renewable electricity generation, allowing project teams to offset energy use by purchasing green power from renewable projects, even if local utility options are unavailable.

Carbon offsets represent a unit of carbon dioxide equivalent that is reduced, avoided, or sequestered to compensate for emissions occurring elsewhere. They are used to offset a building's energy use when renewable energy production is not feasible, allowing project teams to contribute to environmental sustainability by compensating for their carbon footprint through investments in renewable energy projects.

1. Generate Renewable Energy: Install photovoltaic cells, solar hot water heaters, or building-mounted wind turbines.

2. Purchase Off-Site Renewable Energy or Carbon Offsets: Buy green power, renewable energy certificates, or carbon offsets to reduce environmental impact and promote renewable energy generation.

Ongoing energy performance is crucial to ensure that a project functions as designed and maintains or improves its performance over time. It helps identify and resolve issues caused by design flaws, construction defects, equipment malfunctions, and deferred maintenance.

Monitoring and verification track energy performance by comparing building performance measurements with predictions from calibrated energy simulations or industry benchmarking tools, helping to identify and resolve any arising problems.

Innovative construction strategies include: 1. Prefabrication 2. Designing for dimensional construction materials

Commissioning is a systematic investigation by skilled professionals that compares building performance with performance goals, design specifications, and the owner's requirements, ensuring that the building meets its operational requirements throughout its lifecycle.

The median cost of commissioning for existing buildings was $0.27 per square foot, yielding whole-building energy savings of 15% with an average simple payback period of 0.7 years, making it a cost-effective means of improving energy efficiency.

LEED recognizes and encourages operational energy performance through its requirements for building commissioning and credits for metering.

Adhering to the owner's project requirements ensures that detailed specifications are prepared at the beginning of the design process and that commissioning is conducted throughout the project's life-cycle, which helps guarantee that the building functions as designed.

Staff training empowers facilities managers with the knowledge and skills necessary to maintain and improve the performance of buildings, leading to better operational efficiency and effectiveness.

Preventive maintenance is crucial as it involves developing a robust program to keep the building in optimal condition, thereby enhancing its performance and longevity.

Strategies include involving occupants in energy efficiency initiatives, promoting energy-efficient equipment, billing tenants based on submeter readings, educating them on energy-saving practices, and providing regular feedback on energy performance.

The MR credit category focuses on minimizing the embodied impacts associated with the entire life-cycle of building materials, including extraction, production, transportation, consumption, and disposal.

Key strategies include:

1. Reduce consumption of materials.
2. Reuse existing materials and buildings.
3. Recycle waste materials.
4. Select materials with environmentally preferable attributes.
5. Use locally-harvested materials.
6. Eliminate waste during the building process.

Life-cycle thinking helps teams make informed and defensible decisions by evaluating the trade-offs associated with materials selection beyond a project's physical and temporal boundaries, leading to more sustainable choices.

LEED addresses the following issues:

• Conservation of materials
• Environmentally, socially, and locally preferable materials
• Waste management and reduction

The highest form of material conservation is reuse, which involves reusing existing buildings or salvaged materials to eliminate the need for new materials and retain cultural value.

Denser, more compact mixed-use neighborhoods require fewer miles of road and less physical infrastructure to support the same number of people, leading to reduced resource consumption and maintenance needs.

Greenwashing is the practice of presenting misinformation to consumers to make a product or policy appear more environmentally friendly than it actually is. This is a challenge for consumers because it complicates the identification of truly sustainable products, making it difficult to compare products with different sustainable attributes.

Using local sources of environmentally preferable products has several benefits:

• Reduces environmental harms associated with transportation.
• Supports the local economy.
• Encourages sustainable practices within the community.

The purpose of establishing a tracking system is to ensure that the general contractor provides waste hauler reports, captures the full scope of waste produced, and monitors the effectiveness of the waste management policy.

Project teams may consider waste-to-energy as a strategy to manage materials that no longer have a use, which can reduce land allocation to landfills.

• Outline procedures and goals for solid waste diversion.
• Specify a target diversion rate for the facility.

To establish baseline performance, identify opportunities for increased recycling, education, and waste diversion.

• Provide easily accessible collectors for recyclables.
• Label all collectors and list allowable materials.
• Educate occupants about the importance of recycling and reducing waste through signage or meetings.

• Use hauler reports or reliable data to monitor and track effectiveness.
• Track performance goals and provide feedback to occupants.

To turn landscaping debris into mulch and allow for the collection and composting of food and other organic materials.

To collect e-waste and furniture on site for proper disposal through donation, reuse, or recycling, allowing occupants to bring items from home.

By promoting new attitudes toward waste, encouraging the reuse and recycling of on-site materials, and improving the waste diversion rate through understanding the waste stream.

28% of the waste stream is recyclable paper and cardboard.

The project team should:

1. Provide recommendations to improve the recycling rate of paper and cardboard.
2. Implement source reduction strategies for these items.
3. Share the audit results with building occupants to encourage participation in recycling programs.

Indoor Environmental Quality (EQ) encompasses conditions inside a building, including air quality, lighting, thermal conditions, and acoustics, and their effects on occupants.

Strategies for addressing Indoor Environmental Quality issues include:

1. Protecting human health
2. Improving quality of life
3. Reducing stress and potential injuries

These strategies can enhance the lives of building occupants and increase the resale value of the building.

Improving Indoor Environmental Quality is important for building owners because it can:

• Enhance the lives of building occupants
• Increase the resale value of the building
• Reduce liability for building owners
• Lead to a large return on investment by improving employees' health and productivity.

The best way to prevent indoor pollutants is to eliminate or control them at the sources. Proper ventilation is the next line of defense to remove any pollutants that do enter. Both strategies should be considered throughout the building life-cycle.

Ensure adequate ventilation by operating ventilation systems to supply ample outside air to occupants, following industry standards like ASHRAE Standard 62.

Use an outdoor airflow measurement device that can measure and control the minimum outdoor airflow rate.

To regulate the supply of air based on occupants' demand through demand-controlled ventilation, which increases airflow if CO2 concentrations exceed a setpoint.

Calibrate sensors and monitors regularly as part of preventive maintenance to ensure accurate data is used to modulate systems.

Enforce a no-smoking policy in the building and around entrances, operable windows, and air intakes, and communicate this policy to occupants.

A green cleaning policy outlines procedures and goals for the custodial program to minimize contaminants, specifying standards for selecting cleaning products and technologies.

Conduct a custodial effectiveness assessment to identify opportunities for improving cleanliness and reducing exposure to harmful contaminants.

Using grilles, grates, or mats at building entrances helps reduce dust, dirt, and contaminants brought in by shoes, along with proper cleaning procedures.

Integrated pest management is a coordinated program of nonchemical strategies that reduces the need for pesticides and other potentially toxic contaminants.

Occupant control of the indoor environment is critical for comfort and satisfaction, as it addresses individual needs for thermal comfort, lighting, acoustics, and ergonomics.

Creating and maintaining a program to divert significant amounts of waste generated from outside sources to appropriate recycling locations is another example of an innovative strategy.

Studies by the Heschong Mahone Group indicate that providing daylighting in classrooms can improve student scores by 7% to 18%. This suggests that natural light positively impacts learning outcomes.

Daylight controls help in dimming or turning off electrical lights when sufficient natural light is available, reducing the need for artificial lighting and saving energy.

Daylighting and natural ventilation can save energy while improving occupants' experience, demonstrating that energy conservation and indoor environmental quality can be integrated rather than viewed as contradictory.

Occupant surveys assess satisfaction with the indoor environment, helping facilities managers identify areas of dissatisfaction and develop corrective action plans to improve comfort.

LEED encourages facilities managers to assess occupant comfort through confidential surveys, evaluating aspects like heating, air-conditioning, acoustics, air quality, and lighting, and developing plans to address any issues identified.

Innovation in LEED encourages additional environmental benefits beyond those achieved through other rating system categories, expanding green building practices with cutting-edge techniques, processes, and products.

Innovation credits are awarded to projects that incorporate innovative strategies and achieve exemplary levels of performance, including the use of pilot credits to test new LEED credit language and technologies.

Innovative strategies rewarded today may become standard credits in future rating systems as LEED evolves, reflecting advancements in green building practices.

One example is developing a comprehensive green building educational program for community members, occupants, or stakeholders.

The Aldo Leopold Legacy Center was the first building recognized by USGBC as carbon neutral, which helped it earn points in the Innovation category.

The greenhouse gas emissions budget was prepared based on the requirements of the World Resources Institute Greenhouse Gas Protocol, accounting for carbon generation and sequestration.