junte/Model
1
0
Fork 0
mirror of https://github.com/Hestia-Homes/Model.git synced 2026-06-30 13:10:47 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

docs: session-7 handover — sheltered alternative walls (RdSAP Table 4 R=0.5)

Browse source 
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Khalim Conn-Kowlessar 2026-06-08 22:50:55 +00:00
parent 3e05c95e65
commit 943f83ed01
1 changed files with 46 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
docs/HANDOVER_API_PROFILING.md
View file

@ -13,16 +13,56 @@ deproven approaches + the meter/shower data-fidelity findings), and the earlier
`energy_rating_current`. Headline gauge:
`PYTHONPATH=/workspaces/model python scripts/eval_api_sap_accuracy.py`.
| metric | session-3 (`a8e5563a`) | session-4 (`faf29942`) | session-5 (`19235d11`) | **session-6 (`a7761ea8`)** |
| metric | session-4 (`faf29942`) | session-5 (`19235d11`) | session-6 (`a7761ea8`) | **session-7 (`3e05c95e`)** |
|--------|------------------|------------------|------------------|------------------|
| **% \|err\| < 0.5** | 45.1% | 47.6% | 53.1% | **53.14%** |
| % \|err\| < 1.0 | 59.4% | 62.6% | 68.0% | **67.99%** |
| % \|err\| < 2.0 | 77.7% | 79.6% | ~81% | **81.85%** |
| mean \|err\| | 1.702 | 1.586 | 1.329 | **1.312** |
| median \|err\| | — | — | 0.467 | **0.467** |
| **% \|err\| < 0.5** | 47.6% | 53.1% | 53.14% | **54.24%** |
| % \|err\| < 1.0 | 62.6% | 68.0% | 67.99% | **69.64%** |
| % \|err\| < 2.0 | 79.6% | ~81% | 81.85% | **83.50%** |
| mean \|err\| | 1.586 | 1.329 | 1.312 | **1.248** |
| median \|err\| | — | 0.467 | 0.467 | **0.457** |
| computed / raises | 909 / 0 | 909 / 0 | 909 / 0 | **909 / 0** |
| unsupported_schema | 100 (deferred) | 100 (deferred) | 100 (deferred) | 100 (deferred) |
### SESSION-7 — sheltered alternative walls (RdSAP Table 4 R=0.5), `3e05c95e`
The headline-moving audit. User: 53% is poor enough to indicate a MAJOR error
— audit again. The decisive diagnostic CHAIN (reusable):
1. **Error by `dwelling_type`** → flats are the drag (houses 60-66% within 0.5,
flats 28-47%; top-floor flat −1.19, mid-floor 28% within 0.5).
2. **Split flats by `mains_gas`** → ELECTRIC flats are the killer (gas flats
~45%, electric flats 13-19%; top-floor electric mean|err| 3.62).
3. **Invert the SAP equation** (ECF = 0.42·cost/(TFA+45) → `sap_rating`) to get
`our_cost / lodged_cost` → electric flats over-cost ~3% median (houses 1.00),
amplified by the 4× electric price + steep low-band log curve (+3% ≈ +1.5 SAP
at band 40).
4. **Under-rate tracks space-heating kWh/m² precisely** — accurate certs 14-110,
under-rating certs 130-289 (cert 2021: 11 275 kWh for 39 m²) → over-stated
FABRIC, not tariff (storage flats on the correct 5.5p rate under-rate just as
much as room-heater flats at 13p).
5. **Field-by-field on the worst** → cert 0340-2976 (band-A flat) computed wall
128 W/K though its main wall is a FILLED cavity (U 0.7); the excess was a
SECOND `u_wall` call — a `sap_alternative_wall_1` timber-frame sub-area at
U=2.5 lodging **`sheltered_wall="Y"`**.
ROOT: the gov-EPC API lodges `sheltered_wall="Y"` per alt-wall, but it was
DROPPED by the schema + domain dataclasses, so `_alt_wall_w_per_k` billed the
sub-area at its full exposed U. RdSAP 10 Table 4 (PDF p.22) "Sheltered": added
external resistance R=0.5 m²K/W → U_sheltered = 1/(1/U + 0.5) — the SAME
adjustment the MAIN wall already applies for `gable_wall_type=2`
(`gable_wall_sheltered`, `_SHELTERED_GABLE_ADDED_RESISTANCE_M2K_W`). Threaded
end-to-end: schema (21.0.0/21.0.1) + domain `SapAlternativeWall.is_sheltered`
(default False → Summary/Elmhurst path unchanged, goldens untouched) +
`from_api_response` `"Y"→True` + `_alt_wall_w_per_k` applies the 0.5 resistance
(lodged-U + basement alts return before it). 140 certs (15% of corpus) carry a
sheltered alt-wall; they under-rated at median −0.82 / signed −1.33 / 23% within
0.5. Eval: 102 improved / 38 regressed (offsetting-error cases — applied
spec-uniformly per the determinism principle); +10 net within-0.5. Goldens +
full regression green, pyright net-zero. **OPEN audit leftovers: electric-flat
tail persists (2021 −3.9 genuine uninsulated solid brick = data-fidelity;
top-floor "Flat, limited insulation" roofs); detached houses 45% (balanced
bidirectional scatter); the 38 sheltering regressions = offsetting errors
elsewhere; main-wall (non-gable) sheltering not audited; multi-element wall
description joined-string-to-all-BPs (113 certs, mild).**
### SESSION-6 — community fuels 30/31/32 collide with electricity codes, `a7761ea8`
Picked up the deferred "fuel-collision part 2". The profiler's strongly-biased
`main_control=2306` bucket (n=11, signed −3.75, nearly uniform) was a PROXY: every