diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdc342d8..84d38f96 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Added
 
+- `enclosure_insertion_loss` now accepts a panel prediction result directly for
+  its `panel_transmission_loss` argument, in addition to a per-band array or a
+  callable. A `SoundReductionResult` or `ApertureTransmissionResult` (from the
+  panel and aperture models) is matched structurally, so its per-band `R` and
+  band centres feed the enclosure calculation without any dependency of
+  `noise_control` on `building`. The predicted panel `R` and a measured `R`
+  are therefore interchangeable at the enclosure input.
 - Atmospheric refraction: ray tracing and the parabolic equation
   (`phonometry.environmental.atmospheric_refraction`, also re-exported at the
   top level). The module is the refracting-atmosphere counterpart of the ocean
diff --git a/docs/api-reference.md b/docs/api-reference.md
index 57bf7922..4cb8ed7c 100644
--- a/docs/api-reference.md
+++ b/docs/api-reference.md
@@ -2,7 +2,7 @@
 
 # API Reference
 
-All core functionality lives in thirteen domain subpackages; every public name
+All core functionality lives in fifteen domain subpackages; every public name
 is also re-exported by the top-level `phonometry` package.
 
 > **Note.** This page is the curated quick table for the GitHub/PyPI audience:
@@ -13,7 +13,7 @@ is also re-exported by the top-level `phonometry` package.
 
 ## Namespaces
 
-The library is organized into thirteen domain subpackages, and importing the
+The library is organized into fifteen domain subpackages, and importing the
 domain namespace is the primary form used throughout the documentation:
 
 ```python
@@ -32,10 +32,11 @@ contour = aircraft.noise_contour(path, powers, distances, sel, lmax, x=gx, y=gy)
 | `phonometry.materials` | Absorption (ISO 354/11654), impedance tube, airflow resistance, scattering/diffusion, road absorption, dynamic stiffness |
 | `phonometry.building` | Sound insulation measurement and prediction (EN 12354, ISO 717/16283/10140/15186/10052/10848), structure-borne sound |
 | `phonometry.vibration` | Human vibration (ISO 2631/5349/8041), multiple shocks, mobility (ISO 7626), transfer stiffness (ISO 10846) |
-| `phonometry.environmental` | Rating levels, ISO 1996-2 measurement, outdoor propagation (ISO 9613), wind-turbine noise, impulsive prominence |
+| `phonometry.environmental` | Rating levels, ISO 1996-2 measurement, outdoor propagation (ISO 9613), atmospheric refraction (ray tracing and the parabolic equation), wind-turbine noise, impulsive prominence |
 | `phonometry.aircraft` | EPNL (ICAO Annex 16), SAE ARP 5534 absorption, airport contours (ECAC Doc 29), rotorcraft (ECAC Doc 32) |
 | `phonometry.underwater` | ISO 18405/17208/18406 levels, propagation, sound speed, sonar equation, seabed, ambient and ship-traffic noise, numerical solvers |
-| `phonometry.electroacoustics` | Distortion (IEC 60268-3 / AES17), transfer function and coherence |
+| `phonometry.electroacoustics` | Distortion (IEC 60268-3 / AES17), transfer function and coherence, radiating piston |
+| `phonometry.noise_control` | Reactive silencers (four-pole method), HVAC duct attenuation, machine-enclosure insertion loss |
 | `phonometry.broadcast` | Programme loudness and true peak (ITU-R BS.1770-5, EBU R 128 with Tech 3341/3342) |
 | `phonometry.simulation` | 2D acoustic FDTD wave simulation (staggered grid, sources, probes, impedance boundaries, obstacles) |
 
diff --git a/llms-full.txt b/llms-full.txt
index 56db3ab5..839c1c04 100644
--- a/llms-full.txt
+++ b/llms-full.txt
@@ -9892,7 +9892,7 @@ vectorization only batches the computation across the channel axis.
 
 # API Reference
 
-All core functionality lives in thirteen domain subpackages; every public name
+All core functionality lives in fifteen domain subpackages; every public name
 is also re-exported by the top-level `phonometry` package.
 
 > **Note.** This page is the curated quick table for the GitHub/PyPI audience:
@@ -9903,7 +9903,7 @@ is also re-exported by the top-level `phonometry` package.
 
 ## Namespaces
 
-The library is organized into thirteen domain subpackages, and importing the
+The library is organized into fifteen domain subpackages, and importing the
 domain namespace is the primary form used throughout the documentation:
 
 ```python
@@ -9922,10 +9922,11 @@ contour = aircraft.noise_contour(path, powers, distances, sel, lmax, x=gx, y=gy)
 | `phonometry.materials` | Absorption (ISO 354/11654), impedance tube, airflow resistance, scattering/diffusion, road absorption, dynamic stiffness |
 | `phonometry.building` | Sound insulation measurement and prediction (EN 12354, ISO 717/16283/10140/15186/10052/10848), structure-borne sound |
 | `phonometry.vibration` | Human vibration (ISO 2631/5349/8041), multiple shocks, mobility (ISO 7626), transfer stiffness (ISO 10846) |
-| `phonometry.environmental` | Rating levels, ISO 1996-2 measurement, outdoor propagation (ISO 9613), wind-turbine noise, impulsive prominence |
+| `phonometry.environmental` | Rating levels, ISO 1996-2 measurement, outdoor propagation (ISO 9613), atmospheric refraction (ray tracing and the parabolic equation), wind-turbine noise, impulsive prominence |
 | `phonometry.aircraft` | EPNL (ICAO Annex 16), SAE ARP 5534 absorption, airport contours (ECAC Doc 29), rotorcraft (ECAC Doc 32) |
 | `phonometry.underwater` | ISO 18405/17208/18406 levels, propagation, sound speed, sonar equation, seabed, ambient and ship-traffic noise, numerical solvers |
-| `phonometry.electroacoustics` | Distortion (IEC 60268-3 / AES17), transfer function and coherence |
+| `phonometry.electroacoustics` | Distortion (IEC 60268-3 / AES17), transfer function and coherence, radiating piston |
+| `phonometry.noise_control` | Reactive silencers (four-pole method), HVAC duct attenuation, machine-enclosure insertion loss |
 | `phonometry.broadcast` | Programme loudness and true peak (ITU-R BS.1770-5, EBU R 128 with Tech 3341/3342) |
 | `phonometry.simulation` | 2D acoustic FDTD wave simulation (staggered grid, sources, probes, impedance boundaries, obstacles) |
 
diff --git a/site/src/content/docs/reference/api/noise_control/enclosures.md b/site/src/content/docs/reference/api/noise_control/enclosures.md
index 986ce7e9..0f1c8b5b 100644
--- a/site/src/content/docs/reference/api/noise_control/enclosures.md
+++ b/site/src/content/docs/reference/api/noise_control/enclosures.md
@@ -31,16 +31,18 @@ Bies terms this net reduction the enclosure *noise reduction*; it is the
 insertion loss of the enclosure.
 
 **The panel transmission loss `R` is supplied by the caller** -- measured, or
-predicted by a panel model -- as a per-band array or a callable of frequency.
-This module never predicts `R` itself; it combines a given `R` with the
-interior absorption. The interior room constant reuses
-[`phonometry.room.room_constant`](/phonometry/reference/api/rooms/steady-field/#room_constant).
+predicted by a panel model -- as a per-band array, a callable of frequency, or
+a panel prediction result (a [`phonometry.building.SoundReductionResult`](/phonometry/reference/api/building/panel-transmission/#soundreductionresult)
+or [`phonometry.building.ApertureTransmissionResult`](/phonometry/reference/api/building/aperture-transmission/#aperturetransmissionresult), matched structurally
+so no dependency on `building` is introduced). This module never predicts
+`R` itself; it combines a given `R` with the interior absorption. The
+interior room constant reuses [`phonometry.room.room_constant`](/phonometry/reference/api/rooms/steady-field/#room_constant).
 
 ## enclosure_insertion_loss
 
 ```python
 enclosure_insertion_loss(
-    panel_transmission_loss: ArrayLike | Callable[[NDArray[np.float64]], ArrayLike],
+    panel_transmission_loss: ArrayLike | Callable[[NDArray[np.float64]], ArrayLike] | PanelTransmissionResult,
     external_area: float,
     internal_area: float,
     internal_absorption: ArrayLike,
@@ -58,7 +60,7 @@ constant `R_i = S_i alpha_i / (1 - alpha_i)`.
 
 | Name | Description |
 | :--- | :--- |
-| `panel_transmission_loss` | Panel transmission loss `R` per band, dB. Either a per-band array (measured or predicted elsewhere) or a callable mapping a frequency array to per-band `R` (then `frequencies` is required). This function does not predict `R`. |
+| `panel_transmission_loss` | Panel transmission loss `R` per band, dB. One of: a per-band array (measured); a callable mapping a frequency array to per-band `R` (then `frequencies` is required); or a panel prediction result carrying `transmission_loss` and `frequencies`, such as the [`SoundReductionResult`](/phonometry/reference/api/building/panel-transmission/#soundreductionresult) of [`phonometry.single_panel_transmission_loss`](/phonometry/reference/api/building/panel-transmission/#single_panel_transmission_loss) / [`phonometry.double_wall_transmission_loss`](/phonometry/reference/api/building/panel-transmission/#double_wall_transmission_loss) or the [`ApertureTransmissionResult`](/phonometry/reference/api/building/aperture-transmission/#aperturetransmissionresult) of [`phonometry.composite_transmission_loss`](/phonometry/reference/api/building/aperture-transmission/#composite_transmission_loss) (its `frequencies` are then used unless *frequencies* is given). This function does not predict `R` itself. |
 | `external_area` | External enclosure surface area `S_E`, m2. |
 | `internal_area` | Internal surface area `S_i` (including the machine), m2. |
 | `internal_absorption` | Mean interior absorption `alpha_i` in `(0, 1)` (scalar or per-band). |
diff --git a/src/phonometry/noise_control/enclosures.py b/src/phonometry/noise_control/enclosures.py
index 574926e3..4f9d1a47 100644
--- a/src/phonometry/noise_control/enclosures.py
+++ b/src/phonometry/noise_control/enclosures.py
@@ -24,17 +24,19 @@
 insertion loss of the enclosure.
 
 **The panel transmission loss ``R`` is supplied by the caller** -- measured, or
-predicted by a panel model -- as a per-band array or a callable of frequency.
-This module never predicts ``R`` itself; it combines a given ``R`` with the
-interior absorption. The interior room constant reuses
-:func:`phonometry.room.room_constant`.
+predicted by a panel model -- as a per-band array, a callable of frequency, or
+a panel prediction result (a :class:`phonometry.building.SoundReductionResult`
+or :class:`phonometry.building.ApertureTransmissionResult`, matched structurally
+so no dependency on ``building`` is introduced). This module never predicts
+``R`` itself; it combines a given ``R`` with the interior absorption. The
+interior room constant reuses :func:`phonometry.room.room_constant`.
 """
 
 from __future__ import annotations
 
 from collections.abc import Callable
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Protocol, cast
 
 import numpy as np
 from numpy.typing import ArrayLike, NDArray
@@ -80,6 +82,22 @@ def plot(self, ax: "Axes | None" = None, **kwargs: Any) -> "Axes":
         return plot_enclosure(self, ax=ax, **kwargs)
 
 
+class PanelTransmissionResult(Protocol):
+    """A panel prediction result exposing a per-band transmission loss.
+
+    A frozen result such as :class:`phonometry.building.SoundReductionResult`
+    or :class:`phonometry.building.ApertureTransmissionResult` carries the
+    predicted transmission loss in ``transmission_loss`` and its band centres
+    in ``frequencies``. Matching structurally (a :class:`typing.Protocol`)
+    lets :func:`enclosure_insertion_loss` accept such a result directly without
+    importing the ``building`` package, so ``noise_control`` keeps no
+    dependency on it.
+    """
+
+    transmission_loss: NDArray[np.float64]
+    frequencies: NDArray[np.float64]
+
+
 def _resolve_frequencies(
     frequencies: ArrayLike | None,
 ) -> NDArray[np.float64] | None:
@@ -116,7 +134,11 @@ def _resolve_panel_r(
 
 
 def enclosure_insertion_loss(
-    panel_transmission_loss: ArrayLike | Callable[[NDArray[np.float64]], ArrayLike],
+    panel_transmission_loss: (
+        ArrayLike
+        | Callable[[NDArray[np.float64]], ArrayLike]
+        | PanelTransmissionResult
+    ),
     external_area: float,
     internal_area: float,
     internal_absorption: ArrayLike,
@@ -129,9 +151,16 @@ def enclosure_insertion_loss(
     constant ``R_i = S_i alpha_i / (1 - alpha_i)``.
 
     :param panel_transmission_loss: Panel transmission loss ``R`` per band, dB.
-        Either a per-band array (measured or predicted elsewhere) or a callable
-        mapping a frequency array to per-band ``R`` (then ``frequencies`` is
-        required). This function does not predict ``R``.
+        One of: a per-band array (measured); a callable mapping a frequency
+        array to per-band ``R`` (then ``frequencies`` is required); or a panel
+        prediction result carrying ``transmission_loss`` and ``frequencies``,
+        such as the :class:`~phonometry.building.SoundReductionResult` of
+        :func:`phonometry.single_panel_transmission_loss` /
+        :func:`phonometry.double_wall_transmission_loss` or the
+        :class:`~phonometry.building.ApertureTransmissionResult` of
+        :func:`phonometry.composite_transmission_loss` (its ``frequencies`` are
+        then used unless *frequencies* is given). This function does not
+        predict ``R`` itself.
     :param external_area: External enclosure surface area ``S_E``, m2.
     :param internal_area: Internal surface area ``S_i`` (including the machine),
         m2.
@@ -145,6 +174,19 @@ def enclosure_insertion_loss(
     s_e = require_positive(external_area, "external_area")
     s_i = require_positive(internal_area, "internal_area")
 
+    if (
+        not callable(panel_transmission_loss)
+        and not isinstance(panel_transmission_loss, (np.ndarray, list, tuple))
+        and hasattr(panel_transmission_loss, "transmission_loss")
+        and hasattr(panel_transmission_loss, "frequencies")
+    ):
+        result = cast("PanelTransmissionResult", panel_transmission_loss)
+        if frequencies is None:
+            frequencies = result.frequencies
+        panel_transmission_loss = np.asarray(
+            result.transmission_loss, dtype=np.float64
+        )
+
     freqs = _resolve_frequencies(frequencies)
     r = _resolve_panel_r(panel_transmission_loss, freqs)
 
diff --git a/tests/noise_control/test_enclosures.py b/tests/noise_control/test_enclosures.py
index 439abaa3..4fd67556 100644
--- a/tests/noise_control/test_enclosures.py
+++ b/tests/noise_control/test_enclosures.py
@@ -73,6 +73,34 @@ def test_callable_requires_frequencies() -> None:
         enclosure_insertion_loss(lambda f: f, 6.0, 5.0, 0.3)
 
 
+def test_panel_result_bridge() -> None:
+    # A predicted SoundReductionResult can be fed straight in; its per-band R
+    # and its frequencies are read from the result, matching an explicit pass.
+    from phonometry import single_panel_transmission_loss
+
+    freqs = np.array([125.0, 250.0, 500.0, 1000.0, 2000.0])
+    panel = single_panel_transmission_loss(freqs, 15.0, critical_frequency=2000.0)
+
+    via_result = enclosure_insertion_loss(panel, 6.0, 5.0, 0.3)
+    via_arrays = enclosure_insertion_loss(
+        panel.transmission_loss, 6.0, 5.0, 0.3, frequencies=freqs
+    )
+    assert np.allclose(via_result.panel_transmission_loss, panel.transmission_loss)
+    assert np.allclose(via_result.frequencies, freqs)
+    assert np.allclose(via_result.insertion_loss, via_arrays.insertion_loss)
+
+
+def test_panel_result_frequencies_override() -> None:
+    # An explicit 'frequencies' wins over the ones carried by the result.
+    from phonometry import single_panel_transmission_loss
+
+    freqs = np.array([125.0, 250.0, 500.0])
+    panel = single_panel_transmission_loss(freqs, 15.0, critical_frequency=2000.0)
+    other = np.array([100.0, 200.0, 400.0])
+    res = enclosure_insertion_loss(panel, 6.0, 5.0, 0.3, frequencies=other)
+    assert np.allclose(res.frequencies, other)
+
+
 def test_result_type_and_plot() -> None:
     res = enclosure_insertion_loss(
         [20.0, 30.0, 40.0], 6.0, 5.0, 0.3,