Underwriting worksheet — No. 12

Portfolio stress tester

Push a rental portfolio through vacancy, rate, rent, and expense shocks, then run a thousand Monte Carlo paths to see how far monthly cash flow can fall and how long the reserves hold.

Basis of estimate: Stabilised monthly rent roll, pre-tax
Leading measure: Survival rate under simultaneous stress
Prepared by: Aldo Chandra, Philadelphia PA

Stressed monthly cash flow

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Turn on a scenario to stress the portfolio.

Supporting measurePer month

Portfolio schedule

Adjust any line; every figure on this page restates immediately.

Properties

Line itemPer month

Liquidity

Line itemAssumption

Cash reserves $

Sets how many months a negative-cash-flow portfolio can survive.

Stress assumptions

Switch a shock off to drop it from the comparison and from the simulation.

Vacancy shock — also drives the Monte Carlo run

Line itemAssumption

Vacancy rate %

Interest rate shock — only bites the adjustable share of the debt

Line itemAssumption

Rate increase %

Portfolio on ARM or variable %

Rent decline — a softer market at renewal

Line itemAssumption

Rent decline %

Expense surge — taxes, insurance, and repairs together

Line itemAssumption

Expense increase %

Simultaneous stress — every shock landing at once. This is the leading figure above.

Portfolio health

Margin on gross rent, spread across doors, and survival across the live scenarios.

ItemScore

Health score, 0 to 100 0

0 critical100 excellent

Monte Carlo

OutcomePer month

Outcome distribution

Scenario comparison

Each shock applied on its own, then all of them together. Survival is months of reserve coverage at that burn rate.

Scenario	Cash flow	Change	Change %	Survival	At risk

Cash flow deviation

Distance from zero. Anything left of the centre rule is a monthly loss.

Property by scenario

Monthly cash flow for each door under each shock.

Green clears $100 a month, amber is $0 to $100, oxblood is negative.

Start a build Want this wired into your own portfolio data? Tell me what you track.

This worksheet gives estimates for planning only. Real vacancy, rate, rent, and repair outcomes will differ from any model, and the Monte Carlo run is a distribution of possibilities rather than a forecast. It is not tax, legal, or investment advice — check the numbers with your own accountant and lender before acting on them.

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