Urban design and architectural planning are increasingly attuned to how local wind conditions shape the human experience in public spaces. High wind speeds or turbulent gusts can diminish pedestrian comfort and, in some cases, pose safety risks. In response, researchers and regulatory bodies have, over the past decades, established a range of criteria to quantify acceptable wind conditions in pedestrian zones. These wind comfort standards support planners, architects, and engineers in designing developments that respect microclimatic realities while fostering a more comfortable and inviting public realm.

With infrared.city you can now study the pedestrian wind comfort for multiple design options, during the times of most interest (example: winter afternoons) or annually. We currently support multiple wind comfort criteria as follows:

• Lawson LDDC (Local Dynamic Design Criteria)
• Lawson 2001
• General Lawson
• Davenport criteria
• NEN 8100 Safety
• NEN 8100 Comfort

Each of these has unique thresholds and the application of either will likely be defined by your project location and the regionally accepted criteria locally. Below is a detailed definition of each criterion.

Overview of the Pedestrian Wind Comfort Criteria

The following sections detail what each criterion represents, its engineering basis, and the interpretation of recommended thresholds. The emphasis is on current implementations and outcomes in urban design.

1.Lawson Criteria Family

Over the years, three related variants of Lawson’s work have influenced urban wind comfort studies:

Lawson LDDC (Local Dynamic Design Criteria)

• Purpose: The Lawson LDDC provides a localized approach that accounts for spatial variation in dynamic airflow. It uses wind tunnel experimentation and computational fluid dynamics (CFD) to simulate wind flow around buildings.
• Interpretation: Its thresholds are tuned for micro-scale effects – recognizing that even small variations in building geometry can substantially change pedestrian wind conditions. The criterion is used to calibrate local design features (e.g., setbacks, facade curvature) to dampen wind accelerations.
• Application: Often used in areas where intricate urban morphologies require a detailed local assessment.

Lawson 2001

• Purpose: An updated version of Lawson’s earlier work (pre-dating LDDC), Lawson 2001 offers revised thresholds influenced by more extensive experimental datasets and computational models.
• Interpretation: The Lawson 2001 criteria include refined thresholds for acceptable wind speeds and gust frequencies based on observations from both wind tunnel tests and field studies.
• Application: Used primarily in medium to large urban projects to guide the design of building clusters and public spaces.

General Lawson (Lawson-1970)

• Purpose: General Lawson criteria act as a more simplified rule-of-thumb design guide for pedestrian wind comfort. While it still draws on extensive research, it offers broader guidance not requiring complex simulations.
• Interpretation: Emphasis is on providing threshold wind speed values that indicate “comfort” versus “discomfort” scenarios, balancing design simplicity with engineering reliability.
• Application: Frequently employed during early project stages or in contexts where detailed wind simulation is not feasible.

2.Davenport Criteria

• Purpose: Originating from work by Davenport and colleagues, these criteria focus on wind comfort from a human perception perspective, integrating considerations of wind turbulence and its frequency.
• Interpretation: Davenport’s guidelines are often used to assess design modifications that influence local airflow; for example, how building shapes or urban form can reduce local turbulence “hot spots.”
• Application: Urban designers and engineers use the Davenport criteria to inform the layout of pedestrian walkways and public plazas, ensuring that gusts and sustained speeds remain within acceptable comfort limits.

3. NEN 8100 Standards

The Netherlands has been a leading region in establishing formal pedestrian wind comfort criteria through the NEN 8100 standards. Two variants are widely recognized:

NEN 8100 Safety

• Purpose: Focused primarily on ensuring that wind conditions do not pose safety hazards, the NEN 8100 Safety criteria set thresholds that aim to prevent events like wind-induced slips or falls.
• Interpretation: In engineering practice, this translates to upper-limit wind speed thresholds (during gust events) that must not be exceeded at typical pedestrian heights.
• Application: In the Netherlands and other regions with similar national standards, this criterion often forms part of the mandatory design review for new and renovated building projects.

NEN 8100 Comfort

• Purpose: Complementing the safety criteria, NEN 8100 Comfort emphasizes the overall user experience in public areas. It defines wind speed and frequency thresholds that delineate the zone of “comfort,” where wind is neither disruptive nor unsettling.
• Interpretation: The comfort thresholds are typically lower than those of safety, ensuring a pleasant pedestrian experience during all seasons.
• Application: For projects that aim to maximize usability and walkability, especially in high-density urban centers, NEN 8100 Comfort is used to benchmark planning decisions.

Quantitative Comparison of Wind Speed and Frequency Thresholds

Below is a summary table listing the key quantitative parameters associated with each of these criteria. The threshold values (in m/s) and the related frequency of such events (as a percentage measure of occurrence) represent typical recommendations found in current practice. While exact numbers may vary by local application and specific project demands, the table provides a comparative overview:

Jurisdictional Frameworks for Wind Comfort Compliance

Several regions around the world have integrated wind comfort studies into their urban development regulations to ensure safe and livable public spaces.

• In The Netherlands, the use of the NEN 8100 Safety and Comfort standards is mandated, forming a core part of the building permit process for new developments.
• The United Kingdom requires pedestrian wind assessments for high-rise and complex urban projects, guided by PAS 2015 and various local planning directives.
• Germany, along with Scandinavian countries such as Denmark and Sweden, follows national DIN standards and urban codes that demand wind evaluations, particularly in dense or sensitive environments.
• In Asia, Hong Kong and mainland China enforce strict regulations requiring pedestrian wind studies in dense urban clusters, especially high-rise areas. Similarly, Japan mandates wind comfort analysis for metropolitan projects to ensure pedestrian safety and usability.
• While North American cities like New York City may incorporate wind studies into design reviews, these requirements are generally less consistent compared to those in Europe or Asia.

Design Implications of Wind Comfort Criteria

Pedestrian wind comfort thresholds serve to both enhance outdoor comfort and ensure safety. Their interpretation must consider:

• Local Microclimates: Urban canyons, street geometries, and building heights can all significantly influence local wind conditions. For example, Lawson LDDC values are tailored for specific locales based on advanced CFD simulations that predict how small geometric alterations affect wind flow.
• Turbulence & Gusts: Not only the average wind speed but also the frequency and intensity of gusts matter. Davenport criteria, for instance, give weight to the impact of intermittent gusts that might cause discomfort even if the mean wind speed is within acceptable limits.
• Safety vs. Comfort: NEN 8100 separates safety and comfort components. Safety thresholds are higher to prevent hazardous conditions (e.g., falls or accidents), whereas comfort thresholds are lower to promote a pleasant pedestrian experience.
• Permitting & Design: In regions with mandatory pedestrian wind comfort studies, the design process incorporates iterative simulations. These studies help refine urban layouts and building geometries before final permit approvals, ensuring that the final design aligns with prescribed wind comfort standards.

Key Takeaways

Pedestrian wind comfort standards have progressed significantly, driven by advancements in wind tunnel experiments, CFD modeling, and field measurements. Among these, the Lawson framework has played a key role in shaping contemporary standards—ranging from localized analyses (Lawson LDDC) and revised thresholds using updated data (Lawson 2001) to more general comfort guidelines (General Lawson). Other approaches, such as Davenport’s emphasis on gust impact and the Netherlands’ NEN 8100 standard—which separates safety and comfort—offer additional tools for safeguarding pedestrian environments.

Ultimately, the integration of these criteria into urban permitting processes highlights the growing recognition of wind as a critical design factor. With countries like the Netherlands, the UK, Germany, and several Asian regions enforcing mandatory assessments, urban planning today is increasingly proactive, adaptive, and centered around human experience. As technologies and research progress, these frameworks will continue to evolve to meet the demands of future cityscapes and shifting climatic conditions.