The lowest headline rate is usually not the cheapest loan. This API compares up to three NZ development or construction facility offers on true total cost: interest on the drawn balance, line fees on either the whole facility or the undrawn portion, and a financed establishment fee, all across a realistic phased drawdown. Returns per-lender totals, effective rate, average drawn, peak debt, and which offer is actually cheapest. No key, no auth, CORS open.
GET https://devstack.co.nz/api/dev-finance
curl "https://devstack.co.nz/api/dev-finance?facility=3000000&months=12&preset=backloaded"
On a $3m facility over 12 months with a back-loaded drawdown, the default comparison set returns Lender A at 7.95% costing $179,481 all-in (13.45% effective) and Lender C at 5.95% costing $221,495 (16.62% effective). The 2 percentage point cheaper rate is $42,000 more expensive, because of a 3% line fee charged on the whole facility while the average drawn balance is only about 44%.
That gap is the entire point of the tool.
facility is the limit. months is the term. preset shapes the drawdown curve. Override any lender with rate1, estab1, line1, lineBasis1 and the same for 2 and 3. lineBasis takes facility or undrawn, which is the single parameter that most changes the answer.
Interactive version: https://devstack.co.nz/calculators/development-finance
Interest accrues on the average drawn balance and capitalises monthly. Line fees are charged on the whole facility by default. The establishment fee is treated as financed from the first advance, so it accrues interest too.
Does not model valuation, legal or QS costs, presale conditions, or exit fees. Verify against full term sheets.
General information for illustrative and educational purposes only. Not financial advice, and not a recommendation of any lender, product or structure. Take advice from a licensed financial advice provider before entering any facility.
Quick feasibility: https://devstack.co.nz/api/quick-feasibility - first-pass NZ development feasibility as JSON
Watercare IGC: https://devstack.co.nz/api/icg - Auckland water and wastewater growth charges
Tools catalogue: https://devstack.co.nz/api/tools - every tool DevStack curates, machine-readable
Agent front door: https://devstack.co.nz/agents
Maintained by DevStack, a curated directory of NZ property development tools, each reviewed by a working Auckland development manager. Free to use and cite with attribution.