Model/packages
Khalim Conn-Kowlessar cd94da4d2e Slice 26: §7 LINE_92/93 closure — RdSAP §15 area rounding on living area
LINE_91 in the worksheet is `living_area / (4)`, where living_area itself
is the §15-rounded materialisation of `Table 27 fraction × TFA`. RdSAP
§9.2 (p.52): "The living area is then the fraction multiplied by the
total floor area." §15 (p.66) lists "All internal floor areas and living
area: 2 d.p." So the actual LINE_91 fed to the §7 zone blend is
`round_half_up(Table_27 × TFA, 2) / TFA`, not the raw Table 27 entry.

The roundtrip explains why the 4 holdout fixtures lodge LINE_91 = 0.3001
or 0.2501 instead of the Table 27 values 0.30 / 0.25:
  000474: 0.30 × 56.79 → 17.04 / 56.79 = 0.3001
  000477: 0.25 × 77.58 → 19.40 / 77.58 = 0.2501
  000490: 0.25 × 66.06 → 16.52 / 66.06 = 0.2501

`_living_area_fraction` now takes TFA and materialises + rounds + divides;
`_living_area_fraction_default` retains the bare Table 27 lookup. Existing
`_round_half_up` from heat_transmission is the right utility (same §15
boundary, same half-up convention).

Scoreboard: §7 cascade pins 52/60 → 60/60 (closes LINE_92/93 on 000474,
000477, 000480, 000490 — and tightens the already-passing 000487/000516
combinations). Full cascade: 304/312 → 312/312 (100%).

e2e SapResult: 27/66 → 56/66 (continuous SAP, ECF, fuel cost, space
heating kWh now close on 5/6 fixtures; 000487 still has unrelated
downstream defects, all 6 CO2 fails await §12).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-23 23:39:20 +00:00
..
domain Slice 26: §7 LINE_92/93 closure — RdSAP §15 area rounding on living area 2026-05-23 23:39:20 +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/.