mirror of
https://github.com/Hestia-Homes/Model.git
synced 2026-06-08 11:17:27 +00:00
61c215bf1f
RdSAP10 §15 p.66 (Rounding of data):
"All internal floor areas and living area: 2 d.p."
Cert 2536 (3 habitable rooms → Table 27 fraction 0.30,
TFA 45.65 m^2) sits ON the HALF_UP rounding boundary:
0.30 (exact) * 45.65 = 13.6950
HALF_UP 2 d.p. = 13.70
(worksheet fLA = 13.70 / 45.65 = 0.3001)
Float arithmetic drops the spec product BELOW the boundary:
0.30 (binary) ~= 0.2999999...
product ~= 13.69499...
HALF_UP 2 d.p. = 13.69
(cascade fLA = 13.69 / 45.65 = 0.29989)
The 0.00021 fLA shortfall feeds straight into the worksheet
(91) -> (92) MIT blend, undershoots MIT by ~0.001 C, and
shaves 0.29 kWh off (98c) useful space heating — a +0.0007
SAP residual via the (211) main heating fuel x p/kWh.
Compute the product in Decimal so HALF_UP lands on the exact
.005 decimal boundary the spec defines. Certs that sit off the
boundary (e.g. 2800/4800: 0.30 x 46.87 = 14.0610 -> 14.06 in
both Decimal and float) are unaffected.
Cohort-2 distribution after S0380.31..S0380.34:
36 exact + 2 <=0.07 (was 35 exact + 3 <=0.07).
Cert 2536: +0.000715 -> -9.2e-8.
The remaining 2800 / 4800 +0.0007 residuals come from a
different cause (off the HALF_UP boundary) — defer to a
separate slice.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
|
||
|---|---|---|
| .. | ||
| addresses | ||
| data_transformation | ||
| epc | ||
| sap10_calculator | ||
| sap10_ml | ||
| tasks | ||
| postcode.py | ||