Lancium Clean Campus
Roof lifecycle — General Roof 8 · DATA_HALL_01
430 calibrated Sentinel-2 acquisitions over 2.3 years and 184 Landsat overpasses, shown as observed. The engine's change-point detector dates the apparent intervention; phase bands on the chart use its dates.
Optical and thermal history
ObservedAvailableLifecycle phases
ModeledThe engine's change-point is this roof's membrane completion (construction). Before / transition / after boundaries use its dates; plateau values are descriptive medians of observed rows inside each phase. The FRESH → CURRENT (degradation) split needs the engine's post-completion degradation model and stays pending.
- 1AvailableBefore membrane completionJun 2, 2024 → Mar 4, 2025
- 2AvailableTransitionMar 4, 2025 → Mar 7, 2025albedo plateau pending
- 3AvailableMembrane regimeMar 7, 2025 → Sep 18, 2026
- 4PendingCurrent statedates from the change-point contractalbedo plateau pending
- Pending
- Normalized trajectory. Sun-geometry / BRDF-normalized albedo trajectory is an engine output (spectral_normalize, lifecycle-aware peer group). Not yet persisted for this roof.
- Available
- Change-points. Engine change-point (blind PELT on the seasonal-controlled series): step up of 0.332 albedo, transition 2025-03-04 → 2025-03-07, 53 of 423 acquisitions confirming on sentinel-2a, sentinel-2b, sentinel-2c. The step coincides with the land-state classifier's membrane-completion date: construction, not an intervention.
Future modeled interventions
ModeledCampus-wideThe same list applies to every roof on this campus until roof-specific engine runs exist. Each becomes a scenario in the Simulator when its engine counterfactual exists; each is compared on capex, energy, peak kW, IT capacity, compute value, carbon, water and lifecycle.
| Intervention | Status | Needs |
|---|---|---|
Hose wash (clean roof) Engine per-roof counterfactual: restore to peer median / historical best / manufacturer prior at age. | Modeled | Run in Simulator |
Pressure wash Higher-cost cleaning tier; same physical chain as hose wash. | Pending | engine counterfactual |
Reflective coating Restore to a manufacturer-stated initial reflectance; embodied carbon pending environmental factors. | Pending | engine counterfactual |
Targeted insulation replacement Replace wet or degraded insulation where a moisture survey shows it; R-value recovery drives the thermal term. | Pending | moisture survey; core cuts; roof assembly R-value (owner) |
Recover with added insulation New membrane over the existing assembly with added polyiso; compares capex, operational and embodied impact over service life. | Pending | roof assembly (owner); engine lifecycle counterfactual; embodied-carbon factors |
Full reroof Tear-off and replacement; the highest capex and embodied-carbon option, longest service-life reset. | Pending | roof assembly (owner); warranty/submittals; engine lifecycle counterfactual; embodied-carbon factors |
What would resolve the roof hypothesis
Campus-wide- Owner data neededRoof assembly and install date. Replaces the manufacturer-prior age curve with the actual product and age.
- Owner data neededWash / coating records. Dates any past cleaning so the persistence statistics can exclude it.
- Owner data neededBAS trends. Converts the modeled cooling response to roof reflectance into an observed one.
Reading this page
- Calibrated broadband albedo (Sentinel-2 L2A, Bonafoni & Sekertekin 2020, calibration v2). Not a CRRC solar reflectance; compare the roof with its own history, not with product data sheets.
- A sun-geometry seasonal cycle is present and not removed — the engine's normalized trajectory is pending. Compare like seasons, or the quarterly medians across years.
- Landsat surface temperature: every roof here is smaller than one native 100 m thermal pixel; use same-acquisition differences, not absolute values.
- Quarterly medians and before/after comparisons are descriptive summaries of observed rows, not a change-point model.