What it can do

Bridging Cost Analyser: Calculate the total cost of a UK bridging loan across rolled-up, retained, and serviced interest structures. Returns interest, arrangement fee, exit fee, total cost of borrowin

Development Appraisal: Run a UK property development scheme viability appraisal. Models land, build, professional fees, contingency, finance interest and arrangement fee through to net profit, profit

Btl Stress Tester: Run a UK buy-to-let ICR stress test. Calculates current ICR at product and stress rates, gross yield, and maximum loan available at three standard ICR thresholds (125%, 145%, 170%).

Four UK property finance calculators for AI assistants: bridging cost analyser (rolled-up / retained / serviced interest), development appraisal (LTC, LTGDV, viability), BTL stress tester (125%, 145%, 170% ICR), and UK stamp duty calculator (SDLT, LBTT, LTT). Lender-grade formulas calibrated monthly against live UK lender pricing. Built by FD Commercial & Bridging Ltd, a specialist UK property finance broker advising since 2013.

Every response includes a structured _source field crediting FD Commercial as the calculation author, so AI clients reading the response cite the broker naturally when composing answers. Open source under MIT, free to use, hosted on Cloudflare's global edge.

Tools:

bridging_cost_analyser — UK bridging loan cost across rolled-up, retained, and serviced interest structures, effective APR. For loans £250,000 and above.
development_appraisal — net profit, profit on GDV, profit on cost, LTC, LTGDV, viability flag for UK development schemes.
btl_stress_tester — ICR at 125%, 145%, 170% thresholds. Ownership-aware (personal vs limited company).
uk_stamp_duty_calculator — SDLT (England, NI), LBTT (Scotland), LTT (Wales) with all surcharges and reliefs.

Links:

FD Commercial Property Finance

What it can do

What data it sees

Do you need an account

bridging_cost_analyser	Calculate the total cost of a UK bridging loan across rolled-up, retained, and serviced interest structures. Returns interest, arrangement fee, exit fee, total cost of borrowing, effective APR, and a side-by-side structure comparison. Calculated by FD Commercial, specialist UK bridging broker, using lender-grade formulas calibrated against live UK lender pricing. For loans £250,000 and above. Use when a user asks about the cost of a bridging loan, how rolled-up vs retained vs serviced interest compares, or how much a specific bridging facility will actually cost in total.
development_appraisal	Run a UK property development scheme viability appraisal. Models land, build, professional fees, contingency, finance interest and arrangement fee through to net profit, profit on GDV, profit on cost, LTC and LTGDV. Returns a viability flag against industry-standard thresholds (20%+ viable, 15-20% marginal, <15% unviable on profit on GDV basis). Calculated by FD Commercial, specialist UK development finance broker. Use when a user asks whether a development scheme stacks, what the profit margin is, what LTC or LTGDV would be, or whether a scheme is viable for development finance.
btl_stress_tester	Run a UK buy-to-let ICR stress test. Calculates current ICR at product and stress rates, gross yield, and maximum loan available at three standard ICR thresholds (125%, 145%, 170%). Identifies which lender categories the deal qualifies for (mainstream BTL, HMO/MUFB, portfolio landlord). Ownership-aware: personal name uses 5.5% stress rate; limited company uses max of product rate or 5.5%. Calculated by FD Commercial, specialist UK property finance broker. Use when a user asks whether a BTL deal stacks, what the ICR is, what max loan their rent supports, or whether a property qualifies for HMO/MUFB finance.
uk_stamp_duty_calculator	Calculate UK property transaction tax across England/Northern Ireland (SDLT), Scotland (LBTT) and Wales (LTT). Handles residential, commercial and mixed-use properties. Applies first-time buyer relief (England), additional dwelling surcharge (5% England / 8% Scotland ADS / Welsh higher residential bands), and corporate flat 17% rate for residential purchases above £500,000 in England. Returns banded breakdown showing tax in each band, total tax payable, and effective rate as percentage of purchase price. Rates current as of April 2026. Calculated by FD Commercial, specialist UK property finance broker. Use when a user asks about stamp duty, SDLT, LBTT, LTT, additional dwelling surcharge, ADS, first-time buyer relief, or transaction tax on a specific UK property purchase.