Abstract every critical date onto the clause that produced it, diarise each option window under the notice terms in that instrument, and hold the drafted notice for the officer who serves it.
A lease is abstracted, and every date it yields carries the clause and the document version behind it.
02
A window opens, and the diary shows the earliest day notice may be given and the latest.
Reason
03
A clause reads two ways, and it is marked ambiguous instead of resolving into one tidy date.
04
A notice falls due, and the method, the address and the recipient come from the instrument.
05
A counting convention differs, and business days, clear days and days from despatch stay apart.
Decide
06
A side letter is filed, and each date that amendment touches is abstracted again before the view refreshes.
07
A rent review lands, and the review dates move with it, along with whatever ran off them.
Out
08
A break option lapses, and the file shows the day it closed and who last saw it.
09
Execute write actions only inside the approval boundaries agreed during implementation.
→Product statement
The agent abstracts the dates and drafts the notice. Whether it is served, and by whom, belongs to a named officer of the occupier.
Example workflow
One option window, lease to notice
AgentHuman
1Lease documents receivedLeases, side letters, licences to alter, rent-review memoranda or renewal deeds
2Lease context assembledThe demise, the property it sits at, the clause the date came from and the version it was read in
3Critical dates draftedThe window, its notice terms, the ambiguities and completeness
4Controls appliedClause-provenance checks, amendment-currency checks, counting checks and completeness confidence
No human action required
Stages 1 to 4 run unaided, and nothing is served at any of them — the agent is abstracting, and the property lane opens at the completeness gate.
5DecisionSplits at the completeness gate
Evidence sufficient
Goes to the real-estate director to approve.
Anything ambiguous
Adds a lease analyst read first.
Property review
The window is held with its clause, its notice terms and the property it sits at.
Approve · Append document · Send to property review
Approved — by the real-estate director▼
6Lease and diary records updatedOnly where write access and records policy allow it
7Outcome evaluatedDate provenance, window coverage, analyst corrections and what review returned
Corrections
Each property correction is counted in the evaluation.
What should not run autonomously
Human approval stays in control
Outside the boundary — human approval required8 items
Serving a notice on a landlord or an agent.
Deciding to exercise or to let a break option go.
Resolving an ambiguous clause into a firm date.
Agreeing a variation to any lease term.
Automation boundaryAgent acts unaided
✓Abstract each critical date with the clause and version behind it.
✓Diarise every option window against the notice terms it carries.
✓Draft the notice for the officer whose name.
✓Mark an ambiguous clause as ambiguous, then route it.
Nothing is served or approved except by a named person, inside the agreed boundaries.
Judging whether a notice was validly given.
Telling a landlord the occupier intends to break.
Setting which counting convention a clause intends.
Changes to the lease record, the diary or the abstract.
Example output
One option window, annotated
Our lease-processing copilot fills the approved form for a broker and our lease and fixed-asset accounting agent builds the schedules a controller posts; this record is one window inside a lease the occupier has already signed.
Diary entry · single windowIllustrative example
Window
Recorded as
Property
Document of record
Confidence
Held for
Break option, tenant only
Read from the break clause and the deed of variation
Regional office
Variation deed, 3 August 2026
Held unserved
The real-estate director, by name
As receivedTaken from the lease and the deed of variation — it reaches as far as those documents do.
What the record holdsExecuted leaseDeed of variationNotice schedule
Why no notice hereWhether to break is the occupier's own decision, and no model may take it.
ActionApproveAppend documentSend to property review
What the score decidesBelow the configured threshold a window picks up a property read before the director sees it.
Value
Where AI adds value
The same four claims, placed at the point in the workflow where each one applies.
Where the value landsValue 01 – 04
Every windowFrom the lease that sets it
03Evidence
Where the evidence is used
A missed option window has no remediation and no appeal: this page holds the dates and the documents behind them, and takes no view on whether to stay, go or renegotiate.
01Approved path
The date is in the lease
Every date is carried with the clause it came from and the document version it was read in, because a date stripped of its clause is only a rumour.
02Human review
What was checked, and not found
No survey of landlord acceptance practice was made, no portfolio-wide census of notice conventions was attempted, and the abstract reaches only as far as the documents actually filed in the repository — an unfiled side letter is invisible to it.
04Build an evidence trail
The lease, the option it carries and the officer who served notice stay on the file.
Integrations
Typical integrations
Five system groups connect to the same agent. Which of them are in scope is decided in discovery.
Lease document sourcesDocument repository · DMS Executed leases and deeds
Lease and diary systemsLease record · diary Critical-date register
Property and estatesEstate register · CAFM Demise and property records
Agent
Lease administration
Reads the leases Abstracts the dates Holds for the director
Notice and matter systemsMatter tracker · post log Served-notice records
Integration availability depends on the client's existing systems and API access.
Agent controls
Six stages between the model and the officer
Six stages walked in order, the last the narrowest of them. Whatever reaches the end is in the map below.
L6 · Outermost — last line of defenceInward → L1 · closest to the model
L6Rollback / safe modeNarrow the agent to evidence assembly when evaluation or production signals degrade.Roll back
L5Version monitoringTrack model, prompt and abstraction rules, and put a lease back through abstraction whenever a new amendment reaches the repository.Track
L4TraceabilityRecord each date, the clause behind it, the version it was read in and every read of the file.Record
L3Director releaseHold the notice for the real-estate director; the hold governs release, not whether the option is worth exercising.Gate
L2Clause guardrailsTest each date against the clause that produced it; where a clause reads two ways, the date is withheld and marked.Restrict
L1Confidence thresholdsRoute an ambiguous window to a lease analyst before the real-estate director sees it.Require review
Model coreDates abstracted — the window, the clause, the notice terms and completeness
L1 – L2Test whether a date may stand
L3Puts the service in a person's hands
L4 – L5Keep the lease and the option behind it
L6Leaves the notice undrafted when signals degrade
How Nestack evaluates it
Evaluate the whole abstract — not only the diary entry that comes out.
Coverage runs the whole depth of the workflow, and every layer is cut by slice.
Surface — the notice a landlord receives
Depth of coverage ▼
E1Final-output evaluationDid the entry record the window the clause actually gives?
E2Step-level evaluationDid the agent read the right lease, the right clause and the current amendment?
E3Tool evaluationDid it read and write the correct lease record and the correct diary?
E4Confidence calibrationDo low-confidence windows actually attract more property corrections?
E5Slice evaluationHow does performance change across specific property types?
E6Business outcomeHow many windows needed a correction before the director approved?
Floor — the option the occupier answers for
Failure modes
Where each failure originates in the agent
Seven failure modes, each placed at the stage that first produces it.
Agent lifecycleDirection of processing →
01 · Retrieval1 mode
KU-03
Stale abstract read
The lease read is not the one the last amendment amended.
Stage gathersThe leases, the clauses, the dates and the deeds
02 · Reasoning2 modes
KU-04
Window closed too early
A counting convention is applied that the clause never set.
KU-06
Ambiguity resolved silently
A clause that reads two ways is abstracted as one date.
Stage proposesThe windows, their clauses and completeness
03 · Tool / write2 modes
KU-02
Thin window passed forward
A window moves on without the analyst read.
KU-05
Bound to the wrong demise
A date is filed against the wrong property.
Stage writesOnly where write access and approval policy allow it
04 · Output1 mode
KU-01
Approved, clause unrecorded
The record shows an approval but not the clause behind it.
Stage returnsThe notice an officer serves and a landlord receives
05 · Change / Version1 mode
KU-07
Silent diary regression
A configuration change moves the window, not the clause.
Stage tracksModel, prompt, abstraction rules and diary fields
Sev-1 · an option window closes undiarisedSev-2 · a wrong date reaches the diarySev-3 · source degrades, notice held undrafted
A property-level date-provenance figure can read clean while leases carried in from acquisitions hold most of the rework. Nestack reports the correction rate by property type, not only in total.
Slice performance — reported separately, not only in aggregateIllustrative example
Slice
Failure rate
Lift
Lift vs. threshold
Status
Leases carried in from acquisitions
6.2%
3.6×
Review
Multi-let office portfolios
4.4%
2.6×
Review
Retail and high-street units
2.8%
1.6×
Watch
Single-let headquarters
1.1%
0.6×
Normal
Bar: correction-rate lift vs. single-let headquarters baseline · scale 0–4.0× · tick marks the 2.0× review threshold2 of 4 slices over threshold
Evidence-linked improvement
What a lapsed option costs
A loop ends when the lapsed break option has become a case the next release must pass. That suite is what the next date diarised is measured against.
Improvement cycle · five stagesSwitchback — the path turns at Improve and returns at Learn
01Detect
Correction rate rises on leases carried in from acquisitions.
02Diagnose
The break option that opened and closed inside one quarter nobody diarised is read back until a single cause remains.
03Improve
Number the change; the leases that drove it are filed underneath it.
04Verify
Each touched lease case is run once more, and one red holds it back.
05Learn
It stays on as a standing test, and the notice rules move alongside it.
Learn → DetectThe return edge. Every window after this one meets a suite one case longer.
Typical build scope
Twelve workstreams across six weeks
The build scope read against the delivery timeline. Week structure follows the six-week plan — discovery, sources, date abstraction, evaluation, integration, then production validation and handover.
WorkstreamWeek 1Week 2Week 3Week 4Week 5Week 6
01Critical-date discovery and automation-boundary work.
02Lease, amendment and estate sources.
03Clause-to-date and notice-provision rule mapping.
04Lease and amendment ingestion.
05Clause, date and document binding.
06Completeness scoring and review routing.
07Director approval workflow.
08Repository and diary integration.
09Critical-date and notice cases.
10Guardrails and service controls.
11Lease-trail instrumentation.
12Deployment, documentation and Agent Care handover.
12 workstreams · 6 weeks · bar shows the weeks a workstream is active — several run in parallelFinal scope and sequence confirmed in discovery
Engagement tiers
What each tier includes
Rows are the capabilities named in each tier's scope. Higher tiers include everything below them.
Capability✓ in scope · — not at this tierPilotOne property, one yearProductionProduction lease workflowAdvancedMultiple properties / entities
Introduced at Pilot
Abstraction to your clause rules✓✓✓
Real-estate director release✓✓✓
Critical-date baseline✓✓✓
Introduced at Production
Reporting by property—✓✓
Approval workflow in your systems—✓✓
Approved write-back—✓✓
Document-repository integration—✓✓
Introduced at Advanced
Multi-landlord lease terms——✓
Cross-portfolio evidence packs——✓
Large lease portfolios——✓
Multi-jurisdiction notice controls——✓
Build priceFrom $5,000From $8,000Custom quote
Final build priceConfirmed after discovery based on integrations, workflow complexity, transaction volume, approval controls and deployment requirements.
Separate from buildBuild pricing is separate from recurring Agent Care, which covers managed monitoring, evaluations, incidents and verified improvements after launch.
What we need from you
What you bring, and what we build with it
Each input maps to a piece of build scope and a week in the delivery timeline.
You bringWe build with it
01Your properties and the leases behind each one→Property mapping and lease captureWeek 1
02Representative leases, deeds and side letters→Clause binding, date logic and the abstraction baselineWeek 2
03Your notice conventions and who may sign one→Clause mapping, date binding and the automation boundaryWeek 1
04Access to relevant APIs, feeds or exports→Repository, lease and estate-source assessment, then integration setupWeek 2
05Dates you would not want missed→Notice cases and the evaluation suiteWeek 4
06What no lease abstract may guarantee→Completeness scoring, review routing, guardrails and release controlsWeek 3
07A named officer who may serve a notice→Director approval workflow, then pilot and production validationWeeks 5–6
Nothing else is requiredDeployment, documentation and Agent Care handover are ours.
Delivery timeline
Four phases across six weeks
These bars are the weeks each phase actually needs and not a drawing, so the fifth holds a pair.
PhaseW1W2W3W4W5W6
DiscoveryW1
BuildW2 – W3
EvaluateW4 – W5
Pilot & LaunchW5 – W6
Week focusW1Lease workflow discovery, clause mapping and the automation boundaryW2Source integration and the critical-date baselineW3Date abstraction, notice logic and release controlsW4Evaluation suite, notice cases and failure-mode testingW5Repository integration, pilot leases and targeted correctionsW6One lease year run under the real-estate director, then Agent Care handover
Reading the bandEach bar covers only the weeks its own work is named for. Week five holds two because the work overlaps there.
At the end of W6When the lease record validates, Agent Care picks the agent up.
DurationSix-week plan shown · typical delivery 4–6 weeks depending on scope confirmed in discovery.
Next step · Facilities AI agent
Build a lease administration agent around the option window nobody put in a diary.
An abstract is only as current as the last amendment filed, and a side letter that never reached the repository moves dates the portfolio view still shows. Show us your leases, your notice provisions and the officer who may serve.
