“We need a wind analysis” covers seven different requests. One is a structural calculation, one is a planning submission, one is a moisture problem, one is about whether anybody will sit on a terrace. They use different tools, answer to different standards, and belong at different points in the design process.
This guide sorts them out, says what each produces, and points to where the detail lives.
What is wind analysis?
Wind analysis is the assessment of how wind interacts with a site and its buildings. It covers seven distinct study types, each answering a different question and each judged against a different standard.
What they share is the input. Every one starts from a directional record of the local wind climate and ends with a number or a map compared against a threshold somebody else set.
The seven types
| Type | The question it answers | Typical output | Judged against |
|---|---|---|---|
| Pedestrian wind comfort | Is it comfortable and safe to walk, stand or sit at ground level, all year? | Comfort category plan at 1.5 to 1.75 m, per season, blended over the direction set | Lawson and LDDC criteria; NEN 8100; City of London Wind Microclimate Guidelines |
| Wind loading | What pressures and forces must the structure and facade resist? | Pressure coefficients by facade zone, base shear and moment, cladding design pressures | ASCE 7 (US); EN 1991-1-4 (EU); IS 875 Part 3 (India); AS/NZS 1170.2 (Australia and New Zealand); National Building Code of Canada |
| Natural ventilation | Will wind and buoyancy move enough air through the building without mechanical help? | Air changes per hour, flow rates through openings, internal air speed | Ventilation rates set by ASHRAE 62.1 and EN 16798-1; CIBSE guidance for the design method |
| Pollutant dispersion | Where does exhaust actually end up, and does it re-enter an intake? | Concentration and dilution fields, intake concentrations, required stack height | ASHRAE Handbook guidance on building air intake and exhaust design; EPA dispersion modeling guidance |
| Wind-driven rain | How much water hits which facades, and where does moisture drive? | Catch ratios per facade from CFD; a wall driving-rain index from ISO 15927-3 | ISO 15927-3 for the driving-rain index; ASHRAE 160 for moisture-control design |
| Snow drifting | Where will snow accumulate, and does it overload a roof or block an exit? | Drift depth and accumulation maps, surcharge loads | ASCE 7 Chapter 7; EN 1991-1-3 |
| Outdoor thermal comfort | Will this outdoor space feel usable, combining wind, sun, radiation and temperature? | UTCI or PET index maps, hours usable per year | Assessed with the UTCI or PET indices. No compliance threshold is set by standard; PET is defined in VDI 3787 Part 2 |
Confirm the edition and clause of any standard against the current published version before citing it in a submission. Chapter numbers move between revisions.
Wind energy siting, assessing a site for power generation, is sometimes grouped in with these. It is an adjacent discipline with its own standards under IEC 61400 and a different buyer, and it is not covered here.
Working back from the question
The fastest way to pick is to start from what you are worried about.
- People outside are uncomfortable, or a planner asked → pedestrian wind comfort
- The structure or the cladding needs a number → wind loading
- You want to avoid mechanical cooling → natural ventilation
- There is a stack, a kitchen extract, a lab or a garage → pollutant dispersion
- Facade staining, or moisture getting into the buildup → wind-driven rain
- Snow country, and a roof with a step in it → snow drifting
- A plaza or terrace nobody uses → outdoor thermal comfort
Where each one goes deeper
- Pedestrian wind comfort, and how CFD compares to wind tunnel measurement: pedestrian wind comfort validation
- The comfort criteria themselves, with thresholds: Lawson wind comfort criteria
- Wind loading, with the ASCE 7 and Eurocode procedures worked through: wind load analysis
- Natural ventilation and the stack effect: stack effect ventilation
- Outdoor and indoor thermal comfort standards: ASHRAE 55 thermal comfort
- The named flow effects, and how to read a wind rose or comfort map: building aerodynamics and wind effects
- The discipline, and what the CFD guidelines prescribe: wind engineering
When to run a wind analysis
The cost of the analysis barely changes across the project. The cost of acting on the answer changes by orders of magnitude.
| Stage | What you can still change | What the analysis is for | Cost of finding out now |
|---|---|---|---|
| Site / feasibility | Everything, including whether to build | Screening: is this site windy, from which directions, will a formal study be required? | Near zero |
| Concept | Massing, height, orientation, podium geometry, tower spacing | Comparing 3 to 6 massing options and killing the bad ones | Low. A massing change costs drawing time |
| Schematic | Facade articulation, canopies, screens, landscape, entrance placement | Testing mitigation. Does the canopy actually fix the entrance? | Moderate. Re-coordination across disciplines |
| Detailed design | Cladding specification, louver sizing, local details | Confirming facade pressures and ventilation rates for submission | High. Structural or facade rework |
| Planning / permit | Almost nothing about form | Producing the report the authority demands | Very high. A failed assessment means redesigning after everything downstream is committed |
| Post-construction | Only add-on mitigation | Diagnosing an actual complaint | Worst case. Retrofitted screens and canopies are expensive, and visible from the street |
A comfort problem found at concept costs a revised massing diagram. The same problem found at planning can cost a redesign. The analysis costs roughly the same at both points; what changes by orders of magnitude is what you have to do about the answer.
The three methods
| Hand calculation and code tables | Wind tunnel | CFD | |
|---|---|---|---|
| What it gives you | A design load or a pass/fail for standard geometry | Measured data at instrumented points | The full 3D field everywhere at once |
| Typical cost | Hours of engineer time | Tens of thousands, plus a physical model | Cloud compute. Free to low for students |
| Typical time | Hours to days | 6 to 12 weeks including model build | Hours per run, many runs in parallel |
| When it is required | Baseline structural compliance, everywhere | Tall or complex buildings; some jurisdictions and peer reviews mandate it | Widely accepted for comfort and microclimate. Not accepted for wind load determination under ASCE 7 |
| Design iteration | Fast, but only for shapes the code anticipated | Very slow. A geometry change means a new model | Fast, which is why it dominates concept and schematic |
| Main limitation | Only valid for anticipated shapes | Cost, lead time, sparse point data, scaling | Quality depends entirely on setup and validation |
Most projects use CFD to explore and, where the jurisdiction requires it, a wind tunnel to confirm. CFD results are only as good as the setup behind them, so ask any tool for its published validation against wind tunnel data.
Wind analysis software: what the options actually are
Three categories, each answering a different stage of the job.
Code calculators automate a standard’s procedure. Enter site data and dimensions, get design pressures. Fast, cheap, submittable, and silent on anything the code tables do not already contain.
Rapid and AI-assisted tools give an instant approximate answer, good enough to compare massing options while the geometry is still moving. They suit concept work; documentation needs something you can defend.
Full CFD platforms solve the flow field. Arbitrary geometry, neighboring buildings, transient response, local peaks. Slower per run than a rapid tool, and the only option once the geometry stops resembling anything in a code table.
What to look for, whichever you pick:
- Published validation against wind tunnel data for building geometries, with the cases and the numbers shown
- Multi-direction runs driven by real climate data, rather than a single assumed direction
- Parallel runs, so comparing options takes one wall-clock cycle
- Import from the CAD you already use, without a remodeling step
- Result extraction at the level you need, down to facade zones
- A criterion set built in (Lawson, NEN 8100) rather than raw velocity you have to classify yourself
SimScale covers the third category in the browser, with the full direction set in a single run. Explore wind simulation or start a free account.
If you are a student or early in your career
Most people reading this page are producing a wind study for a project review rather than a planning submission. That is a legitimate use with its own standard of rigor.
What a defensible student wind study contains:
| Deliverable | Why it earns marks |
|---|---|
| A wind rose for the site | It is the input to everything else, and it shows you sourced real climate data. How to read one |
| A massing comparison | 2 to 4 options run on identical settings. The comparison is the argument, and it is the part a tutor can actually interrogate |
| A ground-level comfort plan | The deliverable a real project would produce. What a comfort map is |
| Before and after mitigation | The problem, the fix, the improvement. The most persuasive pair of images you will produce |
| A named criterion | “Assessed against Lawson LDDC for standing comfort.” Naming it is what makes the work an analysis |
Worth being straight about the scope: a student wind study supports a design argument, and a consultant’s report carries professional liability. They are different documents. What makes the student version defensible is stating where the wind data came from, which criterion was applied, and what was assumed.
Five mistakes that cost marks:
- Using one wind direction instead of the full rose
- No seasonal weighting, so a summer ventilation claim rests on annual data
- Ignoring the surrounding buildings, which are usually the dominant influence
- Presenting velocity magnitude as though it were a comfort category
- Never stating which criterion was used
Frequently asked questions
The assessment of how wind interacts with a site and its buildings, covering pedestrian comfort, structural loads, ventilation, pollutant dispersion and more. It spans seven distinct study types, each answering a different question and judged against a different standard.
Pedestrian wind comfort, wind loading, natural ventilation, pollutant dispersion, wind-driven rain, snow drifting, and outdoor thermal comfort. Wind energy siting, which assesses a site for power generation, is an adjacent field with its own standards under IEC 61400.
Work back from the question. Comfort of people outside means pedestrian wind comfort. Structure and facade means wind loading. Air through the building means natural ventilation. Exhaust and intakes means pollutant dispersion. Usability of an outdoor space means outdoor thermal comfort.
As early as concept. At concept you can still change massing, height and orientation, which are the variables that most affect wind. By permit stage the analysis costs the same but acting on the result can mean redesigning the building.
It depends on jurisdiction and building type. Wind loading is required essentially everywhere by structural code, through ASCE 7, EN 1991-1-4 and national equivalents. Pedestrian comfort assessment is mandated in some places, including the Netherlands via NEN 8100 and the City of London via its wind microclimate guidelines, and discretionary elsewhere. Check with the local authority before assuming.
A wind tunnel gives measured data at specific points, costs tens of thousands and takes 6 to 12 weeks. CFD gives the full 3D field, costs orders of magnitude less, runs in hours and lets you iterate, but its accuracy depends on setup and validation. Most projects use CFD to explore and a wind tunnel to confirm where required.
Most commonly the Lawson and LDDC criteria, or NEN 8100 in the Netherlands. The thresholds and categories for each are set out in the wind comfort criteria article.
Three categories: code calculators that automate a standard’s procedure, rapid or AI-assisted tools that give instant approximate answers for comparing options, and full CFD platforms that solve the flow field for arbitrary geometry. They serve different stages of the same project.
Yes, to support a design argument. A defensible student study states where its wind data came from, names the comfort criterion applied, and compares options on identical settings. Cloud CFD puts the compute within reach; a consultant’s report is a different document with professional liability attached.
