Model/datatypes/epc
Khalim Conn-Kowlessar 3ff864bf86 Cohort residual slice 12: Simplified Type 2 RR geometry (common walls <1.8m)
Extends `SapRoomInRoof` with six optional fields capturing the RdSAP10
§3.9.2 Simplified Type 2 lodgement: common_wall_length_m / height_m
plus two gable length/height pairs.

Type 2 fires when `common_wall_height_m` is set and < 1.8 m (otherwise
the space is a separate storey). Geometry per spec page 23:
  A_common_wall = L × (0.25 + H)
  A_gable       = L × (0.25 + H_gable)
                  − Σ ((H_gable − H_common_wall_i)² / 2)
  A_RR_final    = A_RR − Σ A_common_wall − Σ A_gable
                  (− party / sheltered / connected when lodged, future
                  slice when a fixture exercises them)

Common walls and gables route to walls_w_per_k at U_main_wall (per spec:
"Common wall U-value is inferred from the U-value of the main wall in
the building part below"). A_RR_final routes to roof_w_per_k at
u_rr_default_all_elements (Table 18 col 4).

Synthetic test: 1-storey cavity-uninsulated dwelling at age B + RR
(floor 10 m², common_wall_length 5 m × 1 m height). Pins
walls_w_per_k = 60 × 1.5 + 6.25 × 1.5 = 99.375 W/K and
roof_w_per_k = 30 × 0.40 + 26.025 × 2.30 = 71.857 W/K at abs=0.001.

No production fixture exercises Type 2 yet — synthetic test is the
unit-level guard until a Type 2 cert lands in the corpus.

Reference: RdSAP 10 (10-06-2025) §3.9.2 page 22-23.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-22 19:32:14 +00:00
..
domain Cohort residual slice 12: Simplified Type 2 RR geometry (common walls <1.8m) 2026-05-22 19:32:14 +00:00
loaders demo generated for use in address2uprn 2026-05-08 14:48:15 +00:00
schema slice 15d: +50 features (gap fill + secondary building part); drop 2 derived 2026-05-17 10:13:03 +00:00
search bolstering testing 2026-04-28 13:46:09 +00:00
surveys Handle wall thickness "Unmeasurable" 🟩 2026-04-30 16:41:16 +00:00
__init__.py testing out rebaselining 2026-02-12 22:25:03 +00:00
construction_age_band.py testing out rebaselining 2026-02-12 22:25:03 +00:00
efficiency.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
floor.py preparing partiy class 2026-02-05 08:54:27 +00:00
fuel.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
heating_controls.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
hotwater.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
main_heating.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
property_type_built_form.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
roof.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
walls.py beginning to assembly the parity class 2026-02-04 18:34:59 +00:00
windows.py testing out rebaselining 2026-02-12 22:25:03 +00:00