Load Generator Agent Skill

You are an agent that retrieves wind speeds, snow loads, wind pressures, and seismic data for any location worldwide using the SkyCiv Load Generator API (standalone.loads namespace). This skill covers all functions, parameters, and design codes.

Prerequisite: Always begin a session with S3D.session.start as the first function. See the skyciv-core skill for auth, options, and the request/response envelope.

Session Start#

Use standalone.loads.start instead of S3D.session.start when running load-generator-only sessions:

{
  "function": "standalone.loads.start",
  "arguments": { "keep_open": false }
}

Alternatively, S3D.session.start also works for sessions that combine load generation with structural analysis.

Supported Design Codes#

`design_code` value	Standard	Load Types
`asce7-10`	ASCE 7-10	Wind, Snow
`asce7-16`	ASCE 7-16	Wind, Snow, Seismic
`asce7-22`	ASCE 7-22	Wind, Snow, Seismic
`as1170`	AS/NZS 1170	Wind, Snow, Seismic (NZS 1170.5)
`en1991`	Eurocode EN 1991	Wind, Snow
`nbcc2015`	NBCC 2015	Wind, Snow
`nbcc2020`	NBCC 2020	Wind, Snow
`is875`	IS 875	Wind
`nscp2015`	NSCP 2015	Wind, Snow, Seismic
`cfe-viento`	CFE Viento (Mexico)	Wind
`cte-db-se`	CTE DB SE-AE (Spain)	Wind

Use standalone.loads.getCountryDesignCodes to fetch the current supported list dynamically.

`standalone.loads.getCountryDesignCodes`#

Returns all supported design codes grouped by country and load type.

{
  "function": "standalone.loads.getCountryDesignCodes",
  "arguments": {}
}

Response includes both human-readable (country_design_code) and API-key versions (API_design_codes). Always use the API_design_codes values in your requests.

`standalone.loads.getSiteData`#

Get site-specific wind speed, snow load, and seismic data for a location with minimal input. Useful for quickly determining site parameters before running a full load calculation.

{
  "function": "standalone.loads.getSiteData",
  "arguments": {
    "site_data": {
      "design_code": "asce7-16",
      "project_address": "Chicago, Illinois",
      "risk_category": "II"
    },
    "api_version": 2
  }
}

Response structure:

{
  "site_data": { "country": "United States", "lat": 41.878, "lng": -87.630, "elevation": 180 },
  "wind_data": { "wind_speed": 115, "wind_speed_unit": "mph" },
  "snow_data": { "snow_load": 25 },
  "seismic_data": { "Z": 0.4, "seismic_zone": 4, "nearest_fault": "...", "D": 18.9 },
  "topography": {}
}

`standalone.loads.getLoads`#

The main function. Returns full design wind pressures and/or snow loads for a building based on site location and building parameters.

{
  "function": "standalone.loads.getLoads",
  "arguments": {
    "project_details": {
      "name": "Project Name",
      "id": "PROJ-001",
      "company": "SkyCiv",
      "designer": "Engineer Name",
      "units": "imperial"
    },
    "site_data": { /* see site_data below */ },
    "building_data": { /* see building_data below */ },
    "site_analysis": { /* optional */ },
    "api_version": 2
  }
}

`site_data` Object#

Defines the location and design code parameters.

Common properties (all design codes)#

Key	Type	Description
`design_code`	`string`	API design code value (see table above)
`project_address`	`string`	Site address — uses Google Maps to geocode. Provide this OR `lat`/`lng`.
`lat`	`float`	Latitude (e.g. `41.8781` for Chicago)
`lng`	`float`	Longitude (e.g. `-87.6298` for Chicago)
`wind_direction`	`string`	Wind direction (towards): `N`, `NE`, `E`, `SE`, `S`, `SW`, `W`, `NW`

Design code specific — `site_data`#

Key	Design Code	Options
`risk_category`	ASCE 7	`I`, `II`, `III`, `IV`
`site_class`	ASCE 7-16	`A`, `B`, `C`, `D`, `D-default`, `E`
`site_class`	ASCE 7-22	`A`, `B`, `BC`, `C`, `CD`, `D`, `DE`, `E`
`site_class`	NBCC 2020	`A`, `B`, `C`, `D`, `E`
`exposure`	ASCE 7 / NSCP 2015	`B`, `C`, `D` (required for topography)
`ari`	AS/NZS 1170	Annual Recurrence Interval in years: `1`, `5`, `10`, `20`, `25`, `50`, `100`, `200`, `500`, `1000`, `2000`, `5000`, `10000`
`sls_and_uls`	AS/NZS 1170	Object: `{ country, design_working_life, importance_level }` — or `false` when using `ari`
`sls_and_uls.country`	AS/NZS 1170	`"australia"` or `"new_zealand"`
`sls_and_uls.design_working_life`	AS/NZS 1170	`"construction_equipment"`, `"5_years"`, `"25_years"`, `"50_years"`, `"100_years"`
`sls_and_uls.importance_level`	AS/NZS 1170	`"1"` through `"5"`
`wind_region`	AS/NZS 1170	`A0`–`A5`, `B1`, `B2`, `C`, `D`, `NZ1`–`NZ4` (optional override)
`recurrence_interval` or `ari`	NBCC	`"10_years"`, `"50_years"`
`importance_level`	NBCC	`"low"`, `"normal"`, `"high"`, `"post_disaster"`
`limit_state`	NBCC	`"SLS"`, `"ULS"`
`importance_category`	IS 875	`I`, `II`, `III`, `IV`
`structure_class_is875`	IS 875	`I`, `II`, `III`, `IV`
`occupancy_category`	NSCP 2015	`I`, `II`, `III`, `IV`, `V`
`return_period`	CFE Viento	`"10-anos"`, `"50-anos"`, `"200-anos"`
`barometric_pressure`	CFE Viento	Default `760` mm Hg
`ambient_temperature`	CFE Viento	Default `25` °C

`site_data.topography` sub-object#

Key	Design Code	Description
`wind_direction`	All	Wind direction for topographic analysis
`topo_image`	All	`true` to return a base64 elevation image
`country`	All	Country name
`terrain_category`	AS/NZS 1170	`CAT1`, `CAT2`, `CAT2.5`, `CAT3`, `CAT4`
`terrain_category`	EN 1991 (UK/Ireland)	`0`, `I`, `II`, `III`, `IV`
`terrain_category`	IS 875 / CFE Viento	`1`, `2`, `3`, `4`
`season_month`	EN 1991	For Belgium, France, UK, Ireland
`distance_inside_town`	EN 1991 (UK/Ireland)	Default `20` m
`distance_from_shore`	EN 1991 (UK/Ireland)	Default `100` m
`displacement_height`	EN 1991 (UK/Ireland)	Default `0`
`snow_region`	AS/NZS 1170	AU: `AN`, `AC`, `AS`, `AT` — NZ: `N1`–`N5`
`snow_terrain_class`	AS/NZS 1170	`1`, `2`, `3`
`snow_area_classification`	AS/NZS 1170 / NBCC	`"alpine"`, `"sub-alpine"` (AS) or `"rural"`, `"exposed-north-treeline"` (NBCC)

User-defined overrides (optional)#

Key	Applicable codes
`wind_speed_override`	ASCE 7, AS/NZS 1170, EN 1991, IS 875, NSCP 2015
`hourly_wind_pressure_override`	NBCC
`snow_load_override`	ASCE 7, AS/NZS 1170, EN 1991, NBCC
`min_roof_snow_load`	ASCE 7

Seismic parameters inside `site_data` — ASCE 7-16 / ASCE 7-22#

{
  "site_class": "D",
  "site_seismic_data": {
    "sd1": 0.96,
    "s1": 0.54,
    "sds": 0.55,
    "tl": 8
  }
}

`building_data` Object#

Defines the structure geometry and load calculation parameters.

Structure types (`building_data.structure`)#

Value	Notes
`"building"`	Default — enclosed/partially-enclosed/open buildings
`"freestanding_wall"`	ASCE 7 and AS/NZS 1170 only
`"truss_tower"`	ASCE 7 only
`"rooftop_equipment"`	ASCE 7-16/22 only
`"solar_panel"`	ASCE 7 and AS/NZS 1170 only
`"signboard"`	EN 1991 only
`"pole"`	EN 1991 only
`"open_frames"`	ASCE 7-16/22 only
`"circular-bin"`	ASCE 7 and AS/NZS 1170 only

Roof profiles (`building_data.roof_profile`)#

Value	Enclosure
`"gable"`	`enclosed`, `partially-enclosed`, `partially-open`
`"monoslope"`	`enclosed`, `partially-enclosed`, `partially-open`
`"hip"`	`enclosed`, `partially-enclosed`, `partially-open`
`"pitched"`	`open`
`"troughed"`	`open`
`"open-monoslope"`	`open`

Wind parameters (`building_data.wind_parameters`)#

Key	Description
`structure_type`	`"mwfrs"` (Main Wind Force Resisting System) or `"cladding"` (Components & Cladding)
`enclosure`	`"enclosed"`, `"partially-enclosed"`, `"partially-open"`, `"open"`
`wind_blockage`	ASCE 7/CFE/AS: `"clear"` or `"obstructed"` — AS/NZS 1170: `"empty"` or `"blocked"`
`gust_effect_factor_override`	ASCE 7-10/16 and NSCP 2015: user-defined Gust Effect Factor

Set wind_parameters: false to skip wind load calculation.

Building dimensions (`building_data.building_dimensions`)#

Key	Description
`length`	Building length
`width`	Building width
`mean_roof_height`	Mean roof height
`height`	Wall height (used when `mean_roof_height` not the primary height input)
`roof_angle`	Roof pitch angle in degrees

Snow parameters (`building_data.snow_parameters`)#

Set snow_parameters: false to skip snow load calculation. Otherwise provide snow-relevant keys per design code.

Seismic parameters (`building_data.seismic_parameters`)#

ASCE 7-16#

{
  "seismic_parameters": {
    "structure_height": 21,
    "R": 8.5,
    "structure_system": "concrete-mrf",
    "Ct": 0.016,
    "x": 0.75,
    "redundancy_factor": 1.0,
    "weights": [
      { "level": "2F", "elevation": "33", "weight": "1200" },
      { "level": "Roof", "elevation": "66", "weight": "800" }
    ]
  }
}

structure_system options: "steel-mrf", "concrete-mrf", "steel-eccentrically-braced", "steel-buckling-restrained", "others".

NZS 1170.5#

{
  "seismic_parameters": {
    "return_period": 2000,
    "site_subsoil_class": "C",
    "T1": "0.67",
    "Sp": 1,
    "mu": 1,
    "weights": [
      { "level": "2", "elevation": "7", "weight": "1000" }
    ]
  }
}

NSCP 2015#

{
  "seismic_parameters": {
    "structure_height": "7",
    "R": "8.5",
    "Ca": "0.440",
    "Cv": "0.640",
    "structure_system": "concrete-mrf",
    "weights": [
      { "level": "2", "elevation": "3.7", "weight": "500" },
      { "level": "3", "elevation": "7",   "weight": "370" }
    ]
  }
}

Freestanding wall dimensions#

{
  "freestandingwall_dimensions": {
    "ground_to_top": 5,
    "wall_width": 10,
    "wall_height": 4,
    "ratio_of_solid_area_to_gross": 0.8,
    "length_of_return_corner": 1.5
  }
}

Circular bin / tank dimensions#

{
  "circular_bin_dimensions": {
    "D": 10,
    "H": 15,
    "C": 1.5,
    "Z": 9,
    "configuration": "isolated",
    "roof_pitch_angle": 15
  }
}

`site_analysis` Object (Optional)#

Run wind calculations for all 8 directions and find the governing direction. Provide per-direction terrain/exposure categories and topographic factors.

ASCE 7 / NSCP 2015#

{
  "site_analysis": {
    "terrain_category_all_directions": {
      "N": "B", "NE": "B", "E": "B", "SE": "C",
      "S": "C", "SW": "C", "W": "C", "NW": "D"
    },
    "topo_factor_all_direction": {
      "N": 1, "NE": 1, "E": 1, "SE": 1,
      "S": 1, "SW": 1, "W": 1, "NW": 1
    }
  }
}

AS/NZS 1170.2#

{
  "site_analysis": {
    "terrain_category_all_directions": {
      "N": "CAT1", "NE": "CAT1", "E": "CAT2.5", "SE": "CAT2.5",
      "S": "CAT4", "SW": "CAT2.5", "W": "CAT2.5", "NW": "CAT1"
    },
    "topo_factor_all_direction":       { "N": 1, "NE": 1, "E": 1, "SE": 1, "S": 1, "SW": 1, "W": 1, "NW": 1 },
    "lee_multiplier_all_direction":    { "N": 1, "NE": 1, "E": 1, "SE": 1, "S": 1, "SW": 1, "W": 1, "NW": 1 },
    "hillshape_multiplier_all_direction": { "N": 1, "NE": 1, "E": 1, "SE": 1, "S": 1, "SW": 1, "W": 1, "NW": 1 }
  }
}

`project_details` Object (Optional)#

Used in generated reports.

Key	Description
`name`	Project name
`id`	Project ID
`company`	Company name
`designer`	Designer name
`client`	Client name
`notes`	Notes
`units`	`"imperial"` or `"metric"` (ASCE 7 only)
`pressure_unit`	Output pressure unit (AS/NZS 1170 only)

Response Structure#

{
  "site_data": {
    "country": "...", "lat": 0.0, "lng": 0.0,
    "elevation": 0.0, "formatted_address": "..."
  },
  "wind_data": {
    "wind_speed": 115,
    "wind_speed_unit": "mph"
  },
  "snow_data": {
    "snow_load": 25
  },
  "topography": {
    "topo_factor": 1.0,
    "terrain_type": "Flat",
    "elevation_image_base64": "..."
  },
  "wind_pressure": {
    "pressure_type": "building",
    "pressure_unit": "psf",
    "elevation_or_location_unit": "ft",
    "pressures": [
      {
        "dirn": "along_L",
        "surface": "windward_wall",
        "elevation": [15, 30, 45],
        "pos_Cpi": [18.5, 20.1, 21.4],
        "neg_Cpi": [28.3, 30.7, 32.5]
      },
      {
        "dirn": "along_L",
        "surface": "leeward_wall",
        "pos_Cpi": -12.5,
        "neg_Cpi": -3.1
      },
      {
        "surface": "roof",
        "zone": "F",
        "pos_Cpi": 10.2,
        "neg_Cpi": -38.5
      }
    ]
  },
  "snow_pressure": null,
  "seismic_results": { ... }
}

wind_pressure.pressures — array of pressure objects, one per surface/zone combination
pos_Cpi — pressure with positive internal pressure coefficient
neg_Cpi — pressure with negative internal pressure coefficient
Values can be scalars (one elevation) or arrays (multiple elevations)

Other Parameters#

Parameter	Description
`api_version`	Default `2.1`. Pass `2` for the previous version.
`report`	Set `false` to skip report generation and reduce response time.

Full Examples#

ASCE 7-16 Wind + Snow#

{
  "auth": { "username": "[email protected]", "key": "YOUR_KEY" },
  "options": { "validate_input": true },
  "functions": [
    { "function": "S3D.session.start", "arguments": { "keep_open": false } },
    {
      "function": "standalone.loads.getLoads",
      "arguments": {
        "project_details": { "name": "Chicago Office", "units": "imperial" },
        "site_data": {
          "design_code": "asce7-16",
          "project_address": "Wacker Avenue, Chicago",
          "risk_category": "II",
          "topography": {
            "wind_direction": "N",
            "exposure": "B",
            "country": "United States",
            "topo_image": false
          }
        },
        "building_data": {
          "design_code": "asce7-16",
          "structure": "building",
          "roof_profile": "gable",
          "building_dimensions": {
            "length": 60,
            "width": 40,
            "mean_roof_height": 30,
            "roof_angle": 18.4
          },
          "wind_parameters": {
            "structure_type": "mwfrs",
            "enclosure": "enclosed"
          },
          "snow_parameters": {}
        },
        "api_version": 2
      }
    }
  ]
}

AS/NZS 1170.2 Wind (Australia)#

{
  "function": "standalone.loads.getLoads",
  "arguments": {
    "site_data": {
      "design_code": "as1170",
      "project_address": "Sydney, NSW",
      "sls_and_uls": {
        "country": "australia",
        "design_working_life": "50_years",
        "importance_level": "2"
      },
      "topography": {
        "wind_direction": "E",
        "terrain_category": "CAT2",
        "country": "Australia",
        "topo_image": false
      }
    },
    "building_data": {
      "design_code": "as1170",
      "structure": "building",
      "roof_profile": "gable",
      "building_dimensions": {
        "length": 20, "width": 15,
        "mean_roof_height": 6, "roof_angle": 15
      },
      "wind_parameters": { "structure_type": "building", "enclosure": "enclosed" },
      "snow_parameters": false
    }
  }
}

EN 1991 (UK)#

{
  "function": "standalone.loads.getLoads",
  "arguments": {
    "site_data": {
      "design_code": "en1991",
      "project_address": "Buckingham Palace, London",
      "topography": {
        "wind_direction": "30",
        "country": "United Kingdom",
        "season_month": "Long-term",
        "terrain_category": "III",
        "distance_inside_town": 20,
        "distance_from_shore": 100,
        "displacement_height": 0,
        "topo_image": false
      }
    },
    "building_data": {
      "design_code": "en1991",
      "structure": "building",
      "roof_profile": "gable",
      "building_dimensions": {
        "length": 30, "width": 20,
        "mean_roof_height": 10, "roof_angle": 20
      },
      "wind_parameters": { "structure_type": "building", "enclosure": "enclosed" },
      "snow_parameters": {}
    }
  }
}

Key Tips#

Address vs coordinates: Use project_address for simplicity. Use lat/lng for precision or when the address is ambiguous.
Skip unwanted loads: Set wind_parameters: false or snow_parameters: false in building_data to skip those calculations and reduce response time.
Skip report generation: Pass "report": false at the top level of arguments to speed up the call when you only need numeric results.
Discover available sections: Run standalone.loads.getCountryDesignCodes first if you're unsure which design_code to use for a given country.
Topographic factor: Set topo_image: true in site_data.topography to receive a base64 PNG of the site elevation profile.
All-direction analysis: Use site_analysis to run all 8 wind directions in one call and get the governing direction automatically.

Session Start#

Supported Design Codes#

standalone.loads.getCountryDesignCodes#

standalone.loads.getSiteData#

standalone.loads.getLoads#

site_data Object#