fix(plans): show effective (modelling) baseline as plan "current" SAP/EPC

Plans are scored against the effective baseline on
property_baseline_performance, which re-baselining can move away from the
lodged EPC shown everywhere else. Using lodged as a plan's "current"
misrepresented the uplift — e.g. lodged C/71 vs effective D/64 with a
post-retrofit C/69.6 read as a downgrade (71 → 69.6) instead of the real
D → C improvement.

Add resolveEffectiveHeadline + getPlanPropertyMeta and switch both plan
pages to it. Legacy properties and backfill gaps fall back to the
lodged/row values.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/portfolio/[slug]/building-passport/[propertyId]/plans/[planId]/page.tsx

@@ -1,6 +1,6 @@
 import RecommendationContainer from "@/app/components/building-passport/RecommendationContainer";
 import {
-  getPropertyMeta,
+  getPlanPropertyMeta,
   getRecommendations,
   getPlanMeta,
   getInstalledMeasuresByUprn,
@@ -59,7 +59,7 @@ export default async function PlanDetail(props: {
   params: Promise<{ slug: string; propertyId: string; planId: string }>;
 }) {
   const params = await props.params;
-  const propertyMeta = await getPropertyMeta(params.propertyId);
+  const propertyMeta = await getPlanPropertyMeta(params.propertyId);
   const [recommendations, planMeta, installedMeasures, scenarioData] =
     await Promise.all([
       getRecommendations(params.planId),

src/app/portfolio/[slug]/building-passport/[propertyId]/plans/page.tsx

@@ -1,4 +1,4 @@
-import { getPlans, getPropertyMeta } from "../utils";
+import { getPlans, getPlanPropertyMeta } from "../utils";
 import { sapToEpc } from "@/app/utils";
 import PlanCard from "./PlanCard";
 import PlanHeroCard from "./PlanHeroCard";
@@ -9,7 +9,7 @@ export default async function RecommendationPlans(props: {
 }) {
   const params = await props.params;
   const [propertyMeta, plans] = await Promise.all([
-    getPropertyMeta(params.propertyId),
+    getPlanPropertyMeta(params.propertyId),
     getPlans(params.propertyId),
   ]);
 

src/app/portfolio/[slug]/building-passport/[propertyId]/utils.ts

@@ -24,6 +24,7 @@ import {
   ConditionReport,
   resolveConditionReport,
   resolvePropertyMeta,
+  resolveEffectiveHeadline,
 } from "@/lib/services/epcSources";
 import { getRating, serializeBigInt } from "@/app/utils";
 import { eq, desc, and } from "drizzle-orm";
@@ -254,6 +255,27 @@ export async function getPropertyMeta(
   return JSON.parse(JSON.stringify(meta, serializeBigInt)) as PropertyMeta;
 }
 
+/**
+ * Property meta for the plan pages. Identical to `getPropertyMeta` except the
+ * "current" SAP/EPC is the effective (modelling) baseline the plans were scored
+ * against, not the lodged EPC — see `resolveEffectiveHeadline`. Legacy
+ * properties and backfill gaps fall back to the lodged/row values.
+ */
+export async function getPlanPropertyMeta(
+  propertyId: string
+): Promise<PropertyMeta> {
+  const meta = await getPropertyMeta(propertyId);
+  const effective = await resolveEffectiveHeadline(
+    BigInt(propertyId),
+    meta.updatedAt
+  );
+  return {
+    ...meta,
+    currentSapPoints: effective.currentSapPoints ?? meta.currentSapPoints,
+    currentEpcRating: effective.currentEpcRating ?? meta.currentEpcRating,
+  };
+}
+
 export async function getConditionReport(
   propertyId: string
 ): Promise<ConditionReport> {

src/lib/services/epcSources.ts

@@ -428,6 +428,36 @@ export async function resolvePropertyHeadline(
   };
 }
 
+/**
+ * Headline SAP score + EPC band for the *plan* pages. Plans are scored against
+ * the modelling baseline (`effective_*` on property_baseline_performance), which
+ * re-baselining can move away from the lodged (gov-registry) EPC we show
+ * everywhere else. Using the lodged figure as a plan's "current" would
+ * misrepresent the uplift — e.g. lodged C/71 vs an effective baseline of D/64
+ * with a post-retrofit C/69.6 reads as a *downgrade* (71 → 69.6) instead of the
+ * real D → C improvement. So plan pages take the effective baseline as "current".
+ *
+ * Returns nulls for legacy properties (no effective/lodged split — keep the
+ * property-row values) and when no baseline row exists yet (backfill gap — fall
+ * back to the lodged headline).
+ */
+export async function resolveEffectiveHeadline(
+  propertyId: bigint,
+  updatedAt: Date | string | null | undefined,
+): Promise<{ currentSapPoints: number | null; currentEpcRating: string | null }> {
+  if (!isNewApproach(updatedAt)) {
+    return { currentSapPoints: null, currentEpcRating: null };
+  }
+  const baseline = await db.query.propertyBaselinePerformance.findFirst({
+    columns: { effectiveSapScore: true, effectiveEpcBand: true },
+    where: eq(propertyBaselinePerformance.propertyId, propertyId),
+  });
+  return {
+    currentSapPoints: baseline?.effectiveSapScore ?? null,
+    currentEpcRating: baseline?.effectiveEpcBand ?? null,
+  };
+}
+
 /** The minimal EPC meta the `/api/property-meta` route embeds as `detailsEpc`. */
 export interface DetailsEpcMeta {
   currentEnergyDemand: number | null;