Model/packages
Khalim Conn-Kowlessar 4479fc69ac Elmhurst 000490: §3 LINE_33 + LINE_37 close exactly
End-to-end §3 fabric heat loss now matches the Elmhurst worksheet to
0.1 W/K (the worksheet displays per-element U-values to 2 d.p.; our
cascade keeps full precision so the totals differ at the third decimal).

Cert inputs lodged on the fixture:
  - roof_insulation_thickness=300 mm on Main and Ext1 → Table 16 U=0.14
  - door_count=2 (cascade default 1.85 m²/door → 3.70 m² worksheet area)
  - WINDOW_TOTAL_AREA_M2=9.03 with WINDOW_AVG_RAW_U_VALUE=2.8 (pre-2002
    double-glazed PVC, 12mm gap; Table 24 row → U_eff=2.518)

Per-part window/door apportionment cancels in the §3 line totals — net
wall sums to the same value whether openings sit on Main or Ext1 — so a
single aggregate area/U pair reproduces (33) exactly.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-20 14:11:07 +00:00
..
domain Elmhurst 000490: §3 LINE_33 + LINE_37 close exactly 2026-05-20 14:11:07 +00:00
fetchers added potential file scaffolding: 2026-05-15 10:56:53 +00:00
repos added potential file scaffolding: 2026-05-15 10:56:53 +00:00
utils added potential file scaffolding: 2026-05-15 10:56:53 +00:00
README.md added potential file scaffolding: 2026-05-15 10:56:53 +00:00

Shared packages

Workspace packages consumed by services/*. Each package is its own Python distribution with its own pyproject.toml; services import via the workspace dependency mechanism ({ workspace = true }).

Package Purpose
domain/ Shared domain types — Property, BaselinePerformance, Plan, Scenario, EpcPropertyData, etc. No persistence, no IO, no business logic.
repos/ Persistence layer — one repo per aggregate. Owns the SQL. Depends on domain.
fetchers/ External API clients (gov EPC, Ofgem, Google Solar, etc.). Depend on domain for response shapes.
utils/ Cross-cutting infra — logging, S3, CloudWatch URL builders, SQS task helpers.

Adding a new shared package

Only when a real second consumer materialises. Don't pre-shatter (repos-epc, repos-property, ...) — split when a deployment needs to drop a dep, not before.

See ../ara_backend_design.md §11 for the broader monorepo layout and ../CONTEXT.md for the domain glossary that names the types living in domain/.