diff --git a/packages/domain/src/domain/sap/calculator.py b/packages/domain/src/domain/sap/calculator.py
index 67a150c2..b571cf52 100644
--- a/packages/domain/src/domain/sap/calculator.py
+++ b/packages/domain/src/domain/sap/calculator.py
@@ -88,6 +88,13 @@ class CalculatorInputs:
     # by §6 orchestrator `solar_gains_from_cert` upstream; the calculator
     # only indexes into it per month, no recomputation here.
     solar_gains_monthly_w: tuple[float, ...]
+    # SAP10.2 (93)m — adjusted mean internal temperature °C per month, and
+    # (94)m — utilisation factor (whole-dwelling Ti) per month. Both come
+    # from §7 orchestrator `mean_internal_temperature_monthly` upstream.
+    # The calculator stops iterating η in _solve_month — Table 9c is a
+    # sequential chain (steps 1-9), not a fixed-point loop.
+    mean_internal_temp_monthly_c: tuple[float, ...]
+    utilisation_factor_monthly: tuple[float, ...]
     region: int
     control_type: int
     responsiveness: float
@@ -182,30 +189,14 @@ def _solve_month(
     g_sol = inputs.solar_gains_monthly_w[month - 1]
     g_total = g_int + g_sol
 
-    # SAP 10.3 §7.3: two-pass iteration. Seed η = 1, compute T_internal,
-    # recompute η from the resulting loss rate, then once more.
-    eta = 1.0
-    t_int = 0.0
-    loss_rate_w = 0.0
-    for _ in range(_ETA_ITERATIONS):
-        t_int = mean_internal_temperature_c(
-            external_temp_c=t_ext,
-            heat_transfer_coefficient_w_per_k=hlc_w_per_k,
-            total_gains_w=g_total,
-            utilisation_factor=eta,
-            time_constant_h=time_constant_h,
-            heat_loss_parameter=heat_loss_parameter,
-            living_area_fraction=inputs.living_area_fraction,
-            control_type=inputs.control_type,
-            responsiveness=inputs.responsiveness,
-            control_temperature_adjustment_c=inputs.control_temperature_adjustment_c,
-        )
-        loss_rate_w = max(0.0, hlc_w_per_k * (t_int - t_ext))
-        eta = utilisation_factor(
-            total_gains_w=g_total,
-            heat_loss_rate_w=loss_rate_w,
-            time_constant_h=time_constant_h,
-        )
+    # SAP 10.2 §7 Table 9c is a sequential chain (steps 1-9); the §7
+    # orchestrator computes (93)m and (94)m upstream and the calculator
+    # consumes them by index. No fixed-point iteration here.
+    _ = time_constant_h  # τ now lives inside the §7 orchestrator
+    _ = heat_loss_parameter
+    t_int = inputs.mean_internal_temp_monthly_c[month - 1]
+    eta = inputs.utilisation_factor_monthly[month - 1]
+    loss_rate_w = max(0.0, hlc_w_per_k * (t_int - t_ext))
 
     q_heat = monthly_heat_requirement_kwh(
         heat_transfer_coefficient_w_per_k=hlc_w_per_k,
diff --git a/packages/domain/src/domain/sap/rdsap/cert_to_inputs.py b/packages/domain/src/domain/sap/rdsap/cert_to_inputs.py
index c35e4cb2..7b8ab16f 100644
--- a/packages/domain/src/domain/sap/rdsap/cert_to_inputs.py
+++ b/packages/domain/src/domain/sap/rdsap/cert_to_inputs.py
@@ -67,6 +67,10 @@ from domain.sap.worksheet.heat_transmission import (
     DwellingExposure,
     heat_transmission_from_cert,
 )
+from domain.sap.climate.appendix_u import external_temperature_c
+from domain.sap.worksheet.mean_internal_temperature import (
+    mean_internal_temperature_monthly,
+)
 from domain.sap.worksheet.solar_gains import solar_gains_from_cert
 from domain.sap.worksheet.ventilation import (
     MechanicalVentilationKind,
@@ -886,6 +890,40 @@ def cert_to_inputs(
             internal_gains_result.total_internal_gains_monthly_w
         )
 
+    solar_gains_monthly_w = solar_gains_from_cert(
+        epc=epc,
+        region=_region_index(epc.region_code),
+        overshading=_INTERNAL_GAINS_DEFAULT_OVERSHADING,
+    ).total_solar_gains_monthly_w
+
+    # SAP10.2 §7 — compose (93)m + (94)m via the orchestrator. Per-month HTC
+    # = transmission HLC + 0.33·V·(25)m. Table 4e control adjustment is 0
+    # for the Elmhurst corpus (cert-side mapping is a future slice).
+    control_type_value = _control_type(main)
+    responsiveness_value = _responsiveness(main)
+    living_area_fraction_value = _living_area_fraction(epc.habitable_rooms_count)
+    monthly_total_gains_w = tuple(
+        internal_gains_monthly_w[m] + solar_gains_monthly_w[m] for m in range(12)
+    )
+    monthly_htc_w_per_k = tuple(
+        ht.total_w_per_k + 0.33 * dim.volume_m3 * ventilation.effective_monthly_ach[m]
+        for m in range(12)
+    )
+    mit_result = mean_internal_temperature_monthly(
+        monthly_external_temp_c=tuple(
+            external_temperature_c(_region_index(epc.region_code), m)
+            for m in range(1, 13)
+        ),
+        monthly_total_gains_w=monthly_total_gains_w,
+        monthly_heat_transfer_coefficient_w_per_k=monthly_htc_w_per_k,
+        thermal_mass_parameter_kj_per_m2_k=_DEFAULT_THERMAL_MASS_PARAMETER_KJ_PER_M2_K,
+        total_floor_area_m2=dim.total_floor_area_m2,
+        control_type=control_type_value,
+        responsiveness=responsiveness_value,
+        living_area_fraction=living_area_fraction_value,
+        control_temperature_adjustment_c=0.0,
+    )
+
     return CalculatorInputs(
         dimensions=dim,
         heat_transmission=ht,
@@ -900,15 +938,15 @@ def cert_to_inputs(
         # (Elmhurst data shows them all as `window_location = External wall`);
         # both pass-throughs are empty. Per-fixture §6 conformance is
         # exercised separately in `test_solar_gains.py`.
-        solar_gains_monthly_w=solar_gains_from_cert(
-            epc=epc,
-            region=_region_index(epc.region_code),
-            overshading=_INTERNAL_GAINS_DEFAULT_OVERSHADING,
-        ).total_solar_gains_monthly_w,
+        solar_gains_monthly_w=solar_gains_monthly_w,
+        # SAP10.2 (93)m + (94)m — adjusted MIT and whole-dwelling η. From
+        # the §7 orchestrator above (Table 9c steps 1-9 sequential, per-zone η).
+        mean_internal_temp_monthly_c=mit_result.adjusted_mean_internal_temp_monthly,
+        utilisation_factor_monthly=mit_result.utilisation_factor_whole_monthly,
         region=_region_index(epc.region_code),
-        control_type=_control_type(main),
-        responsiveness=_responsiveness(main),
-        living_area_fraction=_living_area_fraction(epc.habitable_rooms_count),
+        control_type=control_type_value,
+        responsiveness=responsiveness_value,
+        living_area_fraction=living_area_fraction_value,
         control_temperature_adjustment_c=0.0,
         thermal_mass_parameter_kj_per_m2_k=_DEFAULT_THERMAL_MASS_PARAMETER_KJ_PER_M2_K,
         main_heating_efficiency=eff,
diff --git a/packages/domain/src/domain/sap/tests/test_bre_worked_examples.py b/packages/domain/src/domain/sap/tests/test_bre_worked_examples.py
index 6f46b3d2..c17fe616 100644
--- a/packages/domain/src/domain/sap/tests/test_bre_worked_examples.py
+++ b/packages/domain/src/domain/sap/tests/test_bre_worked_examples.py
@@ -27,8 +27,12 @@ from domain.sap.calculator import (
     CalculatorInputs,
     calculate_sap_from_inputs,
 )
+from domain.sap.climate.appendix_u import external_temperature_c
 from domain.sap.worksheet.dimensions import Dimensions
 from domain.sap.worksheet.heat_transmission import HeatTransmission
+from domain.sap.worksheet.mean_internal_temperature import (
+    mean_internal_temperature_monthly,
+)
 
 
 def _baseline_dwelling() -> CalculatorInputs:
@@ -60,18 +64,36 @@ def _baseline_dwelling() -> CalculatorInputs:
         total_external_element_area_m2=200.0,  # synthetic placeholder
         total_w_per_k=150.0,
     )
+    internal_gains_monthly_w = (450.0,) * 12
+    solar_gains_monthly_w = (
+         70.1510, 118.4419, 161.4420, 202.5589, 231.7608, 232.9177,
+        223.3279, 200.6543, 175.3023, 130.5274,  83.7805,  60.2212,
+    )
+    ext_temp_monthly_c = tuple(external_temperature_c(0, m) for m in range(1, 13))
+    total_gains_monthly_w = tuple(
+        internal_gains_monthly_w[m] + solar_gains_monthly_w[m] for m in range(12)
+    )
+    htc_monthly_w_per_k = tuple(
+        ht.total_w_per_k + 0.33 * dim.volume_m3 * 0.7 for _ in range(12)
+    )
+    mit_result = mean_internal_temperature_monthly(
+        monthly_external_temp_c=ext_temp_monthly_c,
+        monthly_total_gains_w=total_gains_monthly_w,
+        monthly_heat_transfer_coefficient_w_per_k=htc_monthly_w_per_k,
+        thermal_mass_parameter_kj_per_m2_k=250.0,
+        total_floor_area_m2=dim.total_floor_area_m2,
+        control_type=2,
+        responsiveness=1.0,
+        living_area_fraction=0.30,
+    )
     return CalculatorInputs(
         dimensions=dim,
         heat_transmission=ht,
         monthly_infiltration_ach=(0.7,) * 12,
-        internal_gains_monthly_w=(450.0,) * 12,
-        # Hand-computed solar (S + N 4 m² panes, g⊥=0.63 FF=0.7 Z=0.77,
-        # UK-avg region 0, vertical) — captured at HEAD so the trace fixture
-        # matches the pre-§6-wiring numerical baseline.
-        solar_gains_monthly_w=(
-             70.1510, 118.4419, 161.4420, 202.5589, 231.7608, 232.9177,
-            223.3279, 200.6543, 175.3023, 130.5274,  83.7805,  60.2212,
-        ),
+        internal_gains_monthly_w=internal_gains_monthly_w,
+        solar_gains_monthly_w=solar_gains_monthly_w,
+        mean_internal_temp_monthly_c=mit_result.adjusted_mean_internal_temp_monthly,
+        utilisation_factor_monthly=mit_result.utilisation_factor_whole_monthly,
         region=0,
         control_type=2,
         responsiveness=1.0,
diff --git a/packages/domain/src/domain/sap/tests/test_calculator.py b/packages/domain/src/domain/sap/tests/test_calculator.py
index 1c6afcea..9d6638d6 100644
--- a/packages/domain/src/domain/sap/tests/test_calculator.py
+++ b/packages/domain/src/domain/sap/tests/test_calculator.py
@@ -25,8 +25,12 @@ from domain.sap.calculator import (
     SapResult,
     calculate_sap_from_inputs,
 )
+from domain.sap.climate.appendix_u import external_temperature_c
 from domain.sap.worksheet.dimensions import Dimensions
 from domain.sap.worksheet.heat_transmission import HeatTransmission
+from domain.sap.worksheet.mean_internal_temperature import (
+    mean_internal_temperature_monthly,
+)
 
 
 def _baseline_inputs() -> CalculatorInputs:
@@ -56,6 +60,28 @@ def _baseline_inputs() -> CalculatorInputs:
         total_external_element_area_m2=200.0,  # synthetic placeholder
         total_w_per_k=150.0,
     )
+    internal_gains_monthly_w = (450.0,) * 12
+    solar_gains_monthly_w = (
+         70.1510, 118.4419, 161.4420, 202.5589, 231.7608, 232.9177,
+        223.3279, 200.6543, 175.3023, 130.5274,  83.7805,  60.2212,
+    )
+    ext_temp_monthly_c = tuple(external_temperature_c(0, m) for m in range(1, 13))
+    total_gains_monthly_w = tuple(
+        internal_gains_monthly_w[m] + solar_gains_monthly_w[m] for m in range(12)
+    )
+    htc_monthly_w_per_k = tuple(
+        ht.total_w_per_k + 0.33 * dim.volume_m3 * 0.7 for _ in range(12)
+    )
+    mit_result = mean_internal_temperature_monthly(
+        monthly_external_temp_c=ext_temp_monthly_c,
+        monthly_total_gains_w=total_gains_monthly_w,
+        monthly_heat_transfer_coefficient_w_per_k=htc_monthly_w_per_k,
+        thermal_mass_parameter_kj_per_m2_k=250.0,
+        total_floor_area_m2=dim.total_floor_area_m2,
+        control_type=2,
+        responsiveness=1.0,
+        living_area_fraction=0.30,
+    )
     return CalculatorInputs(
         dimensions=dim,
         heat_transmission=ht,
@@ -63,15 +89,14 @@ def _baseline_inputs() -> CalculatorInputs:
         # Synthetic baseline internal gains: 450 W constant. Real
         # per-month variation lives in §5 orchestrator output; tracer
         # tests don't need the modulation to verify the SAP loop.
-        internal_gains_monthly_w=(450.0,) * 12,
+        internal_gains_monthly_w=internal_gains_monthly_w,
         # Hand-computed solar (S + N 4 m² panes, g⊥=0.63 FF=0.7 Z=0.77,
-        # UK-avg region 0, vertical) — captured from §6 leaves at HEAD
-        # so this synthetic baseline keeps the same heat-balance gains
-        # as before the §6 wiring slice.
-        solar_gains_monthly_w=(
-             70.1510, 118.4419, 161.4420, 202.5589, 231.7608, 232.9177,
-            223.3279, 200.6543, 175.3023, 130.5274,  83.7805,  60.2212,
-        ),
+        # UK-avg region 0, vertical) — captured from §6 leaves at HEAD.
+        solar_gains_monthly_w=solar_gains_monthly_w,
+        # §7 (93)m + (94)m precomputed from the orchestrator above so the
+        # baseline reflects spec-correct sequential per-zone η.
+        mean_internal_temp_monthly_c=mit_result.adjusted_mean_internal_temp_monthly,
+        utilisation_factor_monthly=mit_result.utilisation_factor_whole_monthly,
         region=0,
         control_type=2,
         responsiveness=1.0,
@@ -108,6 +133,28 @@ def test_calculator_consumes_solar_gains_monthly_w_field_for_per_month_solar() -
         assert monthly.solar_gains_w == 100.0
 
 
+def test_calculator_consumes_mean_internal_temp_and_utilisation_monthly_fields() -> None:
+    # Arrange — replace baseline inputs' MIT + η with explicit known 12-tuples.
+    # The §7 orchestrator produces these upstream; the calculator must just
+    # look them up, not iterate or recompute. 18.0 °C MIT + 0.8 η constant
+    # everywhere — distinct enough that any leftover iteration would drift.
+    explicit_mit = (18.0,) * 12
+    explicit_eta = (0.8,) * 12
+    inputs = replace(
+        _baseline_inputs(),
+        mean_internal_temp_monthly_c=explicit_mit,
+        utilisation_factor_monthly=explicit_eta,
+    )
+
+    # Act
+    result = calculate_sap_from_inputs(inputs)
+
+    # Assert
+    for monthly in result.monthly:
+        assert monthly.internal_temp_c == 18.0
+        assert monthly.utilisation_factor == 0.8
+
+
 def test_calculator_returns_twelve_month_breakdown_and_plausible_sap_score() -> None:
     # Arrange — baseline 100 m² gas-boiler dwelling in UK-average climate.
     inputs = _baseline_inputs()