Fitting sealed glazing units changes two things beyond the pane's U/g
that the cascade reads, which the overlay didn't model — leaving the
double/secondary before→after pins ~0.7 SAP short (xfail):
1. Draught-proofing (RdSAP 10 §8.1). Sealed units draught-proof the panes
they replace, re-lodging the dwelling-level `percent_draughtproofed`
(cert 001431: 84 → 100). The §2 cascade reads that dwelling-level
value, so the overlay now carries it. `_recompute_percent_draughtproofed`
anchors on the lodged before-% — `after = round((round(before%/100 × N)
+ flips) / N × 100)`, N = openable windows (vertical + roof) + doors,
flips = upgraded panes that were not draught-proofed — so it's robust
to incomplete window extraction (unchanged openings are already in the
aggregate). ~0.3 SAP.
2. Frame factor (§6 solar gains). A replacement unit re-lodges its own
FF=0.70, overriding the pane it replaced — the two "single glazing,
known data" panes lodge FF 1.00 / 0.50 (one is 6.6 m²), so leaving them
unchanged understated solar gains by ~+150 kWh space heating. `WindowOverlay`
now carries `frame_factor`, written flat onto the window. ~0.4 SAP.
Wiring: `EpcSimulation.percent_draughtproofed` + `WindowOverlay.frame_factor`
new fields; `apply_simulations` / `_fold_window` write them; the glazing
generator computes both from the upgraded set and cert 001431's after.
Un-xfails `test_{double,secondary}_glazing_overlay_reproduces_the_relodged_after`
— both now pin SAP/CO2/PE to the relodged after within tolerance. Updates
the two `test_glazing_recommendation` overlay expectations for the new
`frame_factor`. 96 modelling tests pass; zero new pyright errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
With the mapper now in main, cert 001431 parses: it lodges four single-glazed
windows — codes 1 ("Single") and 15 ("single glazing, known data", a single
pane with manufacturer U/g). The generator only detected code 1, so it missed
two panes. Detect {1, 15}; set the secondary target to code 11 ("Secondary
glazing - Normal emissivity", what the cert re-lodges; score-neutral vs 7 but
exact).
A deterministic green pin proves the overlay reproduces the after's 14 windows
exactly. The full-SAP before->after pins are xfail(strict) tripwires: the
overlay nails the windows, but the measure also re-lodges percent_draughtproofed
84->100 (sealed units draught-proof the replaced openings) plus a ~0.4 SAP
fabric residual the overlay doesn't model yet — a glazing-measure coupling to
close later.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Slice 3 of the glazing generator (ADR-0022): a conservation/listed/heritage
protection (PlanningRestrictions.blocks_external) hard-picks secondary_glazing
instead of double_glazing -- an internal second pane, since the external units
can't be replaced on a protected building. Each single-glazed window upgrades
to the secondary target pinned from cert 001431 (glazing_type=7, u_value=2.90,
solar_transmittance=0.85 -- the outer single pane still drives solar gain).
The before/after cascade pins for both measures remain deferred behind the
glazing-label mapper coverage (owned by another agent).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The glazing Recommendation Generator (ADR-0022): detect single-glazed
windows (SAP10.2 Table U2 code 1) and emit one "Windows" Recommendation whose
single Option rewrites every single-glazed window to the double-glazing target
pinned from cert 001431's before->after (glazing_type=5, u_value=1.40,
solar_transmittance=0.72). The overlay writes the per-window U/g into
WindowTransmissionDetails because the calculator consumes those directly.
Priced as a flat per-window average x count. No single-glazed windows -> None.
Planning gate (-> secondary) and the before/after cascade pins land next; the
pins are blocked on glazing-label mapper coverage (owned by another agent).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
