Overlays, tasks & cross-cuts

Two cross-cuts that don't belong in any aggregate. Overlays are categorical groupings of leaves by form-of-record (BASPI5, TA6, NTS2, CON29R, …). Tasks are real-world questions that pull leaves from across the model (cladding, knotweed, leasehold extension). Both are filters over the same leaf universe — they don't change what's there, only how you find it.

How aggregates, overlays and tasks compose

Overlay leaf counts

Each leaf in the schema is referenced by zero or more overlays. The counts below come from data-dictionary-canonical.json — every entry where source ≠ pdtf-transaction.

Total overlay references: 3,463 across 15 overlays. Many leaves carry references from multiple overlays (e.g. propertyPack.address.postcode is in 6 of them). See page 16 — Overlays for the full catalogue and per-overlay drill-down.

Task index

Six task-shaped questions that pull leaves from across the aggregate pages. Each task names the leaves it needs and the canonical page that owns each.

Cladding & EWS1

Leaves: condition.cladding (39) · condition.ews1.rating (39) · buildingSafety.remediationStatus (39) · searches.con29R.planningNotices (46) · documents.ews1Form (48).

Cladding history determines mortgageability. Pull the cladding declaration from condition, the EWS1 rating, any active remediation, and the local-authority notice for the building. Cross-check against the TA6 building-safety section. If EWS1 is B1 or B2, expect lender enquiries; if absent, expect a delay.

Japanese knotweed

Leaves: condition.knotweed (39) · condition.knotweed.treatmentPlan (39) · disclosures.environmental (48) · searches.environmentalReport (46).

Knotweed is a declaration leaf on TA6 with cascading evidence requirements. Pull the declaration, the treatment plan (if any), the warranty, and any environmental search flag. Lender appetite varies; a managed treatment plan often satisfies a high-street lender, an active untreated infestation usually does not.

Leasehold extension

Leaves: legalEstate.tenure (38) · legalEstate.lease.unexpiredTerm (38) · legalEstate.lease.groundRent.escalation (38) · encumbrances.serviceCharge (47) · documents.leaseDeed (48).

Short leases (under 80 years) and doubling ground rents are the two leaf patterns that trigger statutory-extension or marriage-value enquiries. Pull tenure, unexpired term, ground rent escalation, and the lease deed itself. Building Safety Act and Leasehold Reform Act changes since 2024 change the maths — flag the date of valuation.

Probate / executor sale

Leaves: participants.capacity (35) · participants.authority.grant (35) · documents.grantOfProbate (48) · legalEstate.proprietors (38).

Capacity is a participant attribute, but in a probate sale it gates conveyancing entirely. Pull capacity, the grant of probate as evidence, the proprietor record on title (still in the deceased's name), and the executor's identity. The mismatch between proprietor and seller is normal here, not an error.

New build with onward chain

Leaves: property.newBuild (37) · chain.position (36) · chain.dependencies (36) · documents.buildWarranty (39) · milestones.developerCompletion (36).

New-build transactions invert the usual chain. The developer's completion date drives everything downstream. Pull chain position, the developer's expected completion, the build warranty (NHBC, LABC), and the linked sale of the buyer's current home. New-build delays don't show up in the chain leaves as transaction delays.

Shared ownership

Leaves: legalEstate.tenure (38) · legalEstate.sharedOwnership.percentage (38) · legalEstate.sharedOwnership.rentSchedule (38) · participants.housingAssociation (35) · encumbrances.staircase (47).

Shared ownership is a leasehold variant with a rent schedule on the unsold equity and a staircasing right. Pull tenure, percentage owned, rent schedule, the housing association as participant, and any prior staircase transactions. Lender criteria differ sharply; many overlays don't model shared ownership cleanly — flag known gaps.

How overlays and tasks are computed

• Overlays are derived from data-dictionary-canonical.json — every entry where source ≠ pdtf-transaction contributes a membership. Render-time chips in leaf tables show up to 3 overlay names plus +N overflow.
• Tasks are hand-curated on this page — each task names its leaves explicitly and the canonical page each leaf lives on. Refreshing a task list is a content-author edit, not a generator change.
• Cross-cuts never own leaves. If a leaf belongs to a task or overlay but no aggregate, that's a coverage bug in the theme map, surfaced as CI invariant #2 (orphan coverage).