Property: Rental Income Modeling for Investment Properties

[jcleow]

Summary

Add rental income modeling to support investment property planning. Many Singaporeans buy properties for rental yield, and this feature is critical for accurate cash flow projections.

Why This Matters

• Investment property cash flow depends heavily on rental income
• Rental yield is a key metric for property investment decisions
• Rental income is taxable and affects overall financial planning
• Vacancy and expenses significantly impact net returns

Proposed Data Fields

interface RentalConfig {
  isRentedOut: boolean
  monthlyRent: number              // Expected monthly rental
  vacancyRatePercent: number       // Typically 5-10%
  annualRentalGrowthPercent: number // Rent increase assumption
  propertyAgentFeeMonths: number   // Typically 0.5-1 month per year
  maintenanceMonthly: number       // Condo fees, repairs
}

Calculations Required

Metric	Formula
Gross Rental Yield	(Annual Rent / Property Value) × 100
Net Rental Yield	((Annual Rent - Expenses) / Property Value) × 100
Effective Monthly Income	Rent × (1 - vacancy%) - maintenance - (agent fee / 12)
Monthly Cash Flow	Rental Income - Mortgage Payment - Property Tax - Maintenance

Tax Implications

• Rental income is taxable at marginal income tax rate
• Deductible expenses: mortgage interest, property tax, maintenance, agent fees
• Net rental income added to personal income for tax calculation

UI Integration

• New "Rental" tab in PropertyPlannerModal results panel
• Toggle for "Is this property rented out?"
• Rental yield summary in property overview
• Integration with cash flow projections

Acceptance Criteria

• User can input expected monthly rent
• User can set vacancy rate assumption
• Gross and net rental yield displayed
• Monthly cash flow calculated (rental - mortgage - tax - maintenance)
• Rental income integrated into timeline projections

Labels

property, enhancement, P1

[linear]

ASS-69