# Unable to run Dragonfly with URBANopt through python: Error: No such command 'hb-models-to-osm'

**URL:** <https://discourse.ladybug.tools/t/unable-to-run-dragonfly-with-urbanopt-through-python-error-no-such-command-hb-models-to-osm/40697>\
**Category:** dragonfly\
**Created:** [August 18, 2026, 9:47pm UTC](https://discourse.ladybug.tools/t/unable-to-run-dragonfly-with-urbanopt-through-python-error-no-such-command-hb-models-to-osm/40697 "2026-08-18T21:47:10Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![lrsanchez](https://discourse.ladybug.tools/letter_avatar_proxy/v4/letter/l/8dc957/32.png) [@lrsanchez](https://discourse.ladybug.tools/u/lrsanchez)\
**Post date:** [August 18, 2026, 9:47pm UTC](https://discourse.ladybug.tools/t/unable-to-run-dragonfly-with-urbanopt-through-python-error-no-such-command-hb-models-to-osm/40697/1 "2026-08-18T21:47:10Z")

</div>

Dear Ladybug Tools Community,

I am trying to figure out the best workflow for an urban building energy modeling project where I am trying to make parametric adjustments as “scenarios” to a set of simulated residential multi-family low-rise apartment buildings. For this example, let’s say I am a weatherization assistance agency looking to explore insulation retrofits for apartment buildings in a specific neighborhood, specifically delineated as a specific census tract. Let’s say I want to look at only apartment buildings between 20,000 and 30,000 square feet that were built before 1980, and let’s say for this specific census tract I have identified 200 of such buildings for my studied census tract. Now, for these buildings, which are being studied for potential retrofits, let’s say there are 5 different insulation materials I am looking at simulating the energy performance of, each of a different insulation R-value. This would mean 200 x 5 = 1,000 EnergyPlus simulations, which is a lot of computational processing for my laptop! My question then is would this be an appropriate use-case for Dragonfly? And more specifically, would I need URBANopt for this or no? Would URBANopt speed of the simulation processing time am I fundamentally misunderstanding the appropriate use for URBANopt? My project does not concern district heating/cooling systems.

I ask about URBANopt, because I have not been able to get it to work.

I tried running this Dragonfly QuickStart example code with URBANOpt, sourced from the dragonfly-energy GitHub page: [GitHub - ladybug-tools/dragonfly-energy: 🐉 Dragonfly extension for energy simulation · GitHub](https://github.com/ladybug-tools/dragonfly-energy)

```python
from dragonfly.model import Model
from dragonfly.building import Building
from dragonfly.story import Story
from dragonfly.room2d import Room2D
from dragonfly.windowparameter import SimpleWindowRatio
from honeybee_energy.lib.programtypes import office_program

# create the Building object
pts_1 = (Point3D(0, 0, 3), Point3D(0, 10, 3), Point3D(10, 10, 3), Point3D(10, 0, 3))
pts_2 = (Point3D(10, 0, 3), Point3D(10, 10, 3), Point3D(20, 10, 3), Point3D(20, 0, 3))
pts_3 = (Point3D(0, 10, 3), Point3D(0, 20, 3), Point3D(10, 20, 3), Point3D(10, 10, 3))
pts_4 = (Point3D(10, 10, 3), Point3D(10, 20, 3), Point3D(20, 20, 3), Point3D(20, 10, 3))
room2d_1 = Room2D('Office1', Face3D(pts_1), 3)
room2d_2 = Room2D('Office2', Face3D(pts_2), 3)
room2d_3 = Room2D('Office3', Face3D(pts_3), 3)
room2d_4 = Room2D('Office4', Face3D(pts_4), 3)
story = Story('OfficeFloor', [room2d_1, room2d_2, room2d_3, room2d_4])
story.solve_room_2d_adjacency(0.01)
story.set_outdoor_window_parameters(SimpleWindowRatio(0.4))
story.multiplier = 4
building = Building('OfficeBuilding', [story])

# assign energy properties
for room in story.room_2ds:
    room.properties.energy.program_type = office_program
    room.properties.energy.add_default_ideal_air()

# create the Model object
model = Model('NewDevelopment', [building])

# create the dragonfly Model object
model = Model('NewDevelopment', [building])

# serialize the dragonfly Model to Honeybee Models and convert them to IDF
hb_models = model.to_honeybee('Building', use_multiplier=False, tolerance=0.01)
idfs = [hb_model.to.idf(hb_model) for hb_model in hb_models]

from ladybug.location import Location

# create the dragonfly Model object
model = Model('NewDevelopment', [building])

# create a location for the geoJSON and write it to a folder
location = Location('Boston', 'MA', 'USA', 42.366151, -71.019357)
sim_folder = './tests/urbanopt_model'
geojson, hb_model_jsons, hb_models = model.to.urbanopt(model, location, folder=sim_folder)

# ============================================================
# ATTEMPT TO SIMULATE THE EXPORTED MODEL WITH URBANOPT
# ============================================================

from dragonfly_energy.run import (
    base_honeybee_osw,
    prepare_urbanopt_folder,
    run_urbanopt
)

# Create the Honeybee/OpenStudio workflow used by URBANopt.
workflow_osw = base_honeybee_osw(
    project_directory=sim_folder,
    epw_file=epw_file,
    skip_report=True
)

print("Workflow OSW:", workflow_osw)

# Create the URBANopt scenario CSV and runner configuration.
scenario_csv = prepare_urbanopt_folder(
    feature_geojson=geojson,
    cpu_count=1,
    verbose=True
)

print("Scenario CSV:", scenario_csv)

# Run URBANopt.
results = run_urbanopt(
    feature_geojson=geojson,
    scenario_csv=scenario_csv
)

print("URBANopt results:", results)

```

And I get this error message:

```auto
Workflow OSW: C:\Users\MyName\tests\urbanopt_model\mappers\honeybee_workflow.osw
Scenario CSV: ./tests/urbanopt_model\honeybee_scenario.csv
b"Usage: python -m dragonfly_energy translate [OPTIONS] COMMAND [ARGS]...\r\nTry 'python -m dragonfly_energy translate --help' for help.\r\n\r\nError: No such command 'hb-models-to-osm'.\r\n"
---------------------------------------------------------------------------
Exception Traceback (most recent call last)
Cell In[24], line 77
     74 print("Scenario CSV:", scenario_csv)
     76 # Run URBANopt.
---> 77 results = run_urbanopt(
     78 feature_geojson=geojson,
     79 scenario_csv=scenario_csv
     80 )
     82 print("URBANopt results:", results)

File ~\anaconda3\Lib\site-packages\dragonfly_energy\run.py:423, in run_urbanopt(feature_geojson, scenario_csv, cpu_count)
    421 if returncode != 0:
    422 print(stderr)
--> 423 raise Exception('Failed to translate HBJSONs to OSMs.')
    425 # ensure that the URBANopt environment paths are set up correctly
    426 folders.retrieve_urbanopt_env_path()

Exception: Failed to translate HBJSONs to OSMs.

```

This tells me that while Dragonfly is able to render the models themselves, the actual energy simulation is not happening because the Honeybee JSON models cannot be translated to OSM? I am confused on how to properly fix this issue. Though the reason for this post largely comes down to asking do I really even need URBANopt to begin with for my project, or can I just rely on Dragonfly + Honeybee? I am using the Dragonfly in pure python just because I still struggle with Grasshopper and I personally prefer the workflow of using python scripts!

Thanks!