Design Methods for Resilient Community Systems

Summary

The Community Resilience Program is developing resilience metrics and integrated models of physical, social, and economic systems at the community scale. These metrics and models evaluate the impacts of hazard events and subsequent recovery of community services and functions, prioritize alternative solutions to address performance gaps, and support decision making for improving community resilience. Assessment at the community scale, rather than the single building or infrastructure scale, provides a broader view of dependencies and cascading consequences that may not otherwise be recognized or considered. A community scale approach identifies the performance required for buildings and infrastructure to meet their intended function (e.g., business, healthcare, education). For a community to fully benefit from integrated resilience planning, design methods and assessment criteria for individual buildings and infrastructure need to incorporate relevant aspects of community resilience performance goals. This project will advance design and assessment methods for buildings and infrastructure  to improve their ability to support the social and economic functions they support and community resilience.

Description

Objective - To advance design and assessment methods for buildings and infrastructure to improve their ability to support the social and economic functions they support and community resilience.

What is the technical idea?  Quantitative approaches to identify and evaluate the performance of the built environment, including interdependencies, cascading effects, consequences, and recovery of community services and functions, are needed to inform design practice, which generally does not take community aspects into consideration beyond life safety. 

Currently, the performance of buildings is primarily focused on public safety and the role of buildings in communities through risk categories (RC). There are four RC levels: RC II provides the basis of design for ‘ordinary’ buildings not included in the other categories, RC I includes unoccupied buildings with low risk to human life, RC III includes buildings with higher occupancy levels (e.g., public assembly areas), and RC IV includes critical buildings (e.g., hospitals, fire and police stations) that need to maintain their functionality following a hazard event. The design-level hazard loads and effects (as defined in ASCE 7) are ‘anchored’ to RC II, and increased for RC III and RC IV buildings; RC I may have the same or somewhat lower hazard loads, depending on the hazard type. However, additional guidance is needed to address functionality of buildings and other structures, before, during, and after a hazard event. PBD  methods and assessment criteria based on community goals are needed to support adequate performance levels of building clusters (a building cluster includes all buildings and infrastructure associated with a community function, such as finance or health care).

The performance of infrastructure systems—energy, communication, transportation, water, waste water, fuel, etc.— may be designed for different design hazard levels than those used for buildings. The variance in hazard design levels for buildings and infrastructure contributes to variance in performance between buildings and infrastructure systems during hazard events.

Performance metrics for recovery of function following a disruptive or damaging hazard event are needed for buildings and infrastructure systems. As community resilience planning assesses ‘time to recovery of functions’, PBD methods and criteria that evaluate the recovery of individual buildings and infrastructure systems are needed to enable community resilience.

PBD methods develop alternate methods to achieve code requirements and to include additional performance criteria beyond current practice, codes, and standards. While PBD is not a new idea, its advancement and wide-spread adoption has been slow. This is due in part to analysis capabilities and to difficulty articulating a persuasive case for improved performance levels for individual buildings or infrastructure. Community resilience focus on functionality strengthen the case for improved performance.

Design methods and assessment criteria can be enhanced by tools that consider the ability of businesses, households, and the community government to meet the needs of the community both before and after hazard events. Tools based on cost-benefit analysis (BCA) have been used from local to national scales. The ongoing work in the Developing Cost-Effective Resource Allocation Strategies to Enhance Community Resilience project is developing methods that consider indirect benefits and co-benefits for both near- and long-term time frames. This work will also inform the development of performance objectives and criteria for physical, social, and economic systems.

Additionally, adaptation, natural systems, and sustainability are also being addressed by communities for planning. Adaptation looks at plans for future changes in areas such as hazards, economic bases, or growth. Sustainability examines choices for today that have minimal impact on future generations. Natural systems can mitigate hazard effects or provide a source of economy (e.g., tourism). The intersection of these design practices with community resilience planning needs to be characterized to improve community resilience planning guidance.

What is the research plan?

NIST guidance documents and tools (e.g., NIST SP 1190 Community Resilience Planning Guide for Buildings and Infrastructure Systems, NIST SP 1197 Economic Decision Guide, the EDGe$ tool) provide flexible, comprehensive methods to evaluate and plan community resilience, based on the performance of the built environment. The Development of a First-Generation Community Resilience Assessment Methodology project will identify community metrics and indicators for physical, social, and economic systems and the services and functions they provide. These metrics also inform the integrated system-of-systems models being developed at NIST in the Development of a First-Generation Systems Modeling project and by the Center for Risk-Based Community Resilience Planning, a NIST-funded Center of Excellence. These methodologies, metrics, and tools will provide a science-based approach for evaluating and improving the resilience of communities, and will inform design practice for the built environment. 

PBD methods and assessment criteria will be developed to address the performance of buildings and infrastructure systems, and the physical, social, and economic functions they support, to  enable community resilience.

The following activities will inform the project focus and development for PBD methods that include community resilience perspectives:   

• Conduct a critical assessment of current codes, standards, regulations, and best practices of buildings and infrastructure.
• Identify gaps and variations between buildings and infrastructure systems for design and performance levels.
• Evaluate the performance of buildings and infrastructure for hazard events and the recover of services and functions, including community impacts.
• Develop performance objectives and assessment criteria to address the gaps and to improve building and infrastructure performance.
• Work with the appropriate organizations to obtain feedback and advance performance objectives across the design and planning activities.

In FY19,

• Develop PBD system reliability assessment method for wind loads on buildings.
• Assess federal agency requirements related to building and infrastructure design, mitigation, and retrofit, and community planning.

In FY20, the following activities will be initiated:

• Examine codes & standards, and identify design implications of changing environmental conditions on buildings and infrastructure systems.
• Begin a new research track, “Integration of Other Design and Planning Practices”, that aims to conduct research and examine compatibility of other disciplines design and planning practices and their implications for resilience design practices. This FY research will include work to :
  • Examine practices, methods, and design approaches for adaptation planning and its relationship with NIST’s resilience planning and design model
  • Examine natural-design practice implications on resilience design
  • Examine sustainability practice implications on resilience design