Model/datatypes
Khalim Conn-Kowlessar 0320341837 Slice 94: API mapper sheltered_sides + floor_type — cert 001479 to 1e-3
Two API mapper gaps surfacing the cert 001479 +1.18 SAP gap post
Slice 93:

(1) `SapVentilation.sheltered_sides` from API `built_form`

The API schema doesn't lodge sheltered_sides as a discrete field —
it's derived per RdSAP §S5 from the dwelling's built_form. The
cascade defaults to 2 when missing (right for Mid-Terrace) but wrong
for detached/semi/end-terrace. Cert 001479 (built_form=2 Semi-
Detached) needs 1 sheltered side; default 2 over-counted shelter
factor → line (21) under by 0.185 → ventilation under by ~2 ACH/yr.

New `_api_sheltered_sides` translator + `_API_BUILT_FORM_TO_
SHELTERED_SIDES` table (1=Detached/0, 2=Semi/1, 3=End-T/1, 4=Mid-T/2,
5=Encl-End/2, 6=Encl-Mid/3) — mirrors the cohort Elmhurst
`_ELMHURST_SHELTERED_SIDES_BY_BUILT_FORM` keyed by the API integer
enum.

(2) `SapBuildingPart.floor_type` from API `floor_heat_loss`

The Slice 87 spec rule for §2(12) suspended-timber-floor infiltration
(`_has_suspended_timber_floor_per_spec` in cert_to_inputs) requires
the Main bp's lowest floor to have `floor_type == "Ground floor"` to
apply the (12)=0.2/0.1 rule. The API mapper wasn't surfacing this
string (only floor_construction_type), so the spec rule short-
circuited to False even for genuine ground floors and the cascade's
line (12) was 0.0 instead of 0.2.

New `_api_floor_type_str` translator + `_API_FLOOR_HEAT_LOSS_TO_
FLOOR_TYPE` table (1="To external air" for cantilevered exposed
floors, 7="Ground floor"). Routes correctly for cert 001479: Main +
Ext1 carry floor_heat_loss=7 → both Ground floor; Ext2 carries
floor_heat_loss=1 → exposed (its is_exposed_floor=True already lifts
the floor U cascade to Table 20).

**Result on cert 001479 API path:**
  SAP delta: +1.18 → +0.0006 (essentially exact match at integer SAP)
  Cascade SAP=69.0100 vs worksheet 69.0094 — within 1e-3 of target.

The remaining ~0.001 SAP gap is dominated by:
  - hot_water_kwh_per_yr: +6.7 (API 2365.0 vs target 2358.3)
  - internal_gains Σ: +25.7 W·months (subtle gain-cascade differences)
  - solar_gains Σ: +1.5 W·months
Sub-1e-3 SAP impact each; would need slice-by-slice diagnosis to
close to the strict 1e-4 bar.

Layer 3 API-mapper-vs-Summary-mapper EpcPropertyData equivalence:
the API path now produces SAP within 0.001 of the Summary path
(Summary Layer 2 = 69.0094 EXACT). API integer SAP = 69 = worksheet
integer SAP = 69 ✓ — matches the API's published energy_rating_
current=69 (zero residual on the production goal metric).

Golden cert residuals: 8 of 10 expectations shifted by Slices 90-94
cascade improvements. Spec-compliance shifts; new residuals pinned.

Pyright: mapper.py 33 → 33.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 08:27:10 +00:00
..
epc Slice 94: API mapper sheltered_sides + floor_type — cert 001479 to 1e-3 2026-05-26 08:27:10 +00:00
magicplan typing and renaming 🟪 2026-05-07 13:26:49 +00:00
__init__.py further breaking up code 2023-07-20 12:24:34 +01:00
datatypes.py further breaking up code 2023-07-20 12:24:34 +01:00
enums.py completed build of new demo portfolio - some fixed required still 2023-11-20 14:42:16 +00:00