Delsyte UK Property Investment Screener methodology

How the UK Property Investment Screener translates inputs into screening outputs—aligned with the tool’s concept registry and technical appendix.

Screening model (not advice)

Inputs are not validated against external market data—verify independently.
Tax has screening (flat) and detailed (banded) modes; detailed is rUK-only and still simplified.
Lender checks are illustrative; underwriting varies by lender and product.
Scope: England/Northern Ireland residential SDLT only (not Scotland LBTT / Wales LTT; not commercial/mixed-use).

Terminology map

Plain label	Technical term	Appendix link
Price cap	Max offer	View in appendix
Financeable price cap	Financeable max offer	View in appendix
Value at asking (vs target return)	NPV at asking	View in appendix
Annualised return	IRR	View in appendix
Debt service cover (Year 1)	DSCR (actual)	View in appendix
Stressed NOI cover (IO)	NOI ÷ stressed IO	View in appendix
Upfront cash needed	Cash required at entry	View in appendix
Worst cash dip	Peak cash required	View in appendix
Extra cash buffer needed	Extra buffer beyond entry	View in appendix
Rent cover (ICR) check	ICR (stressed)	View in appendix
What would need to change?	Break-evens (at asking)	View in appendix
Sensitivity scenarios	Sensitivity	View in appendix
Saved comparisons	Comparison workspace	View in appendix
Benchmark deal	Baseline	View in appendix
Only show like-for-like comparisons	Show only comparable to baseline	View in appendix

Quick facts

Timing

Monthly cashflows; Year 0 purchase; exit included in final month for NPV/IRR. Annual projection summarises operating years; exit proceeds are shown separately.

Discount rate

Base rate plus liquidity premium.

Price cap (Max offer) solver

Targets Price cap (Max offer) by default with Target value = £0 at the hurdle rate (i.e., NPV = £0), with optional Target annualised return (Target IRR) or Target value (Target NPV) targets.

Not this

Debt service cover (Year 1) (DSCR (actual)) and Rent cover (ICR) check (ICR (stressed)) do not constrain Price cap (Max offer).

Valuation vs exit

Refi valuation follows capital growth with optional post-refurb valuation; exit sale price can be manual or derived from valuation or growth assumptions.

SDLT

Auto-calculated unless you override.

Key inputs

Purchase price, acquisition costs, refurbishment spend, and refurb spend timing (upfront or spread).
Rent model: single-let monthly rent or HMO rooms × average room rent, with void/refurb/lease-up months, operating costs (including HMO utilities, council tax, broadband, cleaning, licensing, consumables), service charges, and overheads toggle. Rent inputs represent the ongoing rent after void/refurb/lease-up timing.
Capex reserve (percent of collected rent or fixed monthly) and optional capex events (repairs vs capital improvements). Repairs reduce operating taxable profit; capital improvements do not.
Financing structure: LTV, interest rate, amortisation choice, fees (cash or capitalised), and refinance events with fees/ERCs.
Growth/inflation assumptions for rent, costs, capital value, and optional post-refurb valuation.
Hold period, sale price assumption (manual or valuation-linked), optional sale price growth, and selling costs.
Discount rate inputs: base rate and liquidity premium.
Ownership and tax mode, plus optional other taxable income for banded calculations.
Distribution modelling and finance cost relief toggles.

Outputs

What you’ll see

Result

Price cap (Max offer) at the hurdle rate, plus optional variants at a target Target annualised return (Target IRR) or target Target value (Target NPV).

Result

Value at asking (NPV at asking), Annualised return (IRR),PI (Profitability index), Upfront cash needed (Cash required at entry), and net exit proceeds.

Result

Worst cash dip (Peak cash required), Extra cash buffer needed (Extra buffer beyond entry), and When cash is tightest (Peak month).

Result

Screening metrics: yields, Debt service cover (Year 1) (DSCR (actual)), Stressed NOI cover (IO) (NOI ÷ stressed IO), cash-on-cash, equity multiple, and payback.

Result

Rent cover (ICR) check (ICR (stressed)) model: max lendable (coverage vs LTV cap) and required rent helper.

Result

Deep dive: projection view, loan and equity path, capex line items, plus detailed breakdowns.

Result

Sensitivity scenarios (Sensitivity) scenarios and optional What would need to change? (Break-evens (at asking)) at asking (including a mode-aware exit break-even aligned to the sale price setting).

Result

Comparisons: Saved comparisons (Comparison workspace), a Benchmark deal (Baseline), and the Only show like-for-like comparisons (Show only comparable to baseline) toggle.

Limitations to keep in mind

Monthly timing with annual aggregation; dividend tax uses annual allowances/bands but accrues monthly from year-to-date dividends.
“Years” are 12-month blocks from purchase (Months 1–12 = Year 1), not aligned to the UK tax year.
Tax treatments remain simplified: no allowance taper, NI, pension/gift aid, or salary/dividend planning; Scotland rates not modeled.
Financing logic and Rent cover (ICR) check (ICR (stressed)) / LTV metrics are illustrative, not lender underwriting.
Percent inputs are clamped to 0–100% and flagged when adjusted, except rent growth and cost inflation (-50% to 50%), and capital growth and sale price growth (-100% to 100%).
Market conditions, pricing, and tenant demand can change quickly.
Inputs are not validated against external data—verify before acting.

How Price cap (Max offer) is calculated

Build monthly cashflows (property after ops tax; or investor after dividends tax when distribution modelling is enabled): Month 0 equity outlay, Months 1..N include rent/opex/debt/tax/capex, final month includes exit proceeds.
Discount to NPV: Σ cashflow(t) / (1 + r)^t where r is the hurdle rate used for Price cap (Max offer).
Solve purchase price for the selected target: Default: Target value = £0 at the hurdle rate (i.e., NPV = £0); target Target annualised return (Target IRR) ⇒ NPV = £0 at the Target annualised return (Target IRR) rate; target Target value (Target NPV) ⇒ NPV = target at the hurdle.
If no price satisfies the target—or the model withholds a result to avoid a misleading number—the solver reports No match found (No solution).
Financeable price cap (Financeable max offer) applies Rent cover (ICR) check (ICR (stressed)) (and optional LTV caps) on top of the target; if lender inputs are incomplete, the financeable value is unavailable.

Safety checks

Debt service cover (Year 1) (DSCR (actual)) = Year 1 NOI / Year 1 debt service.
Stressed NOI cover (IO) (NOI ÷ stressed IO) assumes interest-only at the stress rate on the current loan balance (including capitalised mortgage fees).
Rent cover (ICR) check (ICR (stressed)) models max lendable using coverage and optional max LTV cap, and powers the Financeable price cap (Financeable max offer).
Input risk warnings flag unusually low selling costs, very high leverage, timing shorter than void/refurb/lease-up, and refinance LTV > 100%.
These checks are illustrative and vary by lender and product.

Scenarios & What would need to change? (Break-evens (at asking))

Scenario shocks (rent ±10%, rate ±1%, exit ±10%) update key metrics; shown as Price cap (Max offer), Annualised return (IRR), Worst cash dip (Peak cash required), Stressed NOI cover (IO) (NOI ÷ stressed IO), and Financeable price cap (Financeable max offer) deltas.
What would need to change? (Break-evens (at asking)) (on demand) solve rent, rate, or sale price at asking for the active target and may show No match found (No solution). Interest rate limits are found by shifting the base interest-rate path while keeping existing refinance and revert spreads intact.

Tax & ownership (simplified)

Company

Corporation tax on (NOI − interest − repair capex events) with loss carry-forward.
Exit gain taxed at corporation tax (simplified).
Optional distribution modelling: shareholder loan + dividends; screening mode uses flat dividend tax, detailed mode uses banded dividend tax.

Personal

Screening mode: flat income tax on rental profit after repair capex events.
Detailed mode: rUK income tax bands/allowance with optional finance cost relief.
Capital gains tax on gain after allowance; detailed mode applies property CGT bands.
No NI, allowance taper, or planning assumptions.

SDLT

Auto-calculated from effective date and SDLT flags unless overridden.
Versioning is shown to support comparisons over time.

Cashflow basis

Cashflow basis used for pricing

Pricing uses the same series shown by the cashflow basis badge in results.

Property pre-tax

Used for: Display view only.

NOI minus debt service (interest + principal), minus capex reserve/events, plus any refinance-event cashflows, before operating tax.

Property after operating tax

Used for: Default pricing basis (unless distributions are enabled).

Pre-tax property cashflow (after capex) minus operating tax. Company: corp tax on (NOI − interest − repair capex events) with loss carry-forward. Personal: screening mode uses flat income tax; detailed mode applies rUK bands/allowance with optional finance cost relief; both modes deduct repair capex events.

Investor after dividends tax

Used for: Pricing when distribution modelling is enabled.

Company after-tax cashflow (after capex) routed through shareholder top-ups/loan repayment first, then monthly dividends (distribution percent applied monthly; optionally all remaining cash at exit). Screening mode uses flat dividend tax with annual allowance tracked across 12-month periods from purchase; detailed mode accrues banded dividend tax monthly from year-to-date dividends.

Model mechanics

Monthly periods with Year 0 purchase and final-month exit. Annual projection summarises operating years only; exit proceeds are shown separately.
Rent is zero during initial void/refurb months and optionally ramps during lease-up.
Lender cover uses stabilised annual rent/costs (ongoing rent level); timing (void/refurb/lease-up) affects cashflow/DSCR, not the lender cover numerator.
Refurb spend is either upfront in month 0 or spread evenly across refurb months (affecting peak cash timing).
Optional post-refurb valuation overrides the refi valuation path after refurb completion.
Rent and cost growth compound annually at year boundaries.
Capex reserves reduce monthly cashflows; capex events hit specified months.
Capex events tagged as capital improvements add to the exit cost basis; repairs do not.
When distribution modelling is enabled, company cash balance is tracked monthly with shareholder top-ups and loan repayment ahead of dividends.
Deterministic penny rounding for repeatable results.
NPV / Annualised return (IRR) discounting uses pounds as doubles with deterministic rounding back to pence.
Annualised return (IRR) is omitted for cashflows with multiple sign changes (non-unique solution).

Versions

Calc engine: [email protected]

Methodology: 2026-01-07

SDLT ruleset: sdlt-rulesets@2025-02-20

Tax ruleset: tax-rulesets@2024-04-06

Runs may record sdlt@override when an override is used, or sdlt@unknown if SDLT context is missing/invalid. Tax rulesets may show tax@unknown if the effective date is missing.

Putting it together

The calculator aggregates inputs into standardized outputs, with the concept registry defining each term and the appendix capturing technical detail. The disclaimer outlines scope and limitations.