Construction
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Overview

This guide covers construction loan payment calculation — including how these programs work, what lenders look for, and how to get started. Qualification requirements vary by lender and program type. All loan programs are subject to credit approval and lender-specific criteria.

• Program availability varies by lender
• Qualification requirements vary by scenario
• Multiple program types available
• Speak with a licensed MLO for your situation

Getting Started

JumboLoan.com works with wholesale and portfolio lenders to provide access to programs not available at retail banks. Start our AI-assisted application or call us to discuss your scenario — a licensed MLO will identify the programs best suited to your situation.

• Start at AIMortgageApplication.com
• Licensed MLO reviews your scenario
• Multiple programs compared simultaneously
• NMLS# 1967971 — verify at NMLSConsumerAccess.org

Estimating construction interest — the method

Construction-period interest confuses borrowers because the balance changes monthly. The estimation shortcut professionals use: because draws accumulate across the build, your average outstanding balance is roughly 50–60% of the final loan amount — so construction interest ≈ final loan × rate × build-years × 0.55. Example: a $1,000,000 construction loan at 8% over a 12-month build ≈ $1,000,000 × 8% × 1 × 0.55 ≈ $44,000 of construction-period interest. Front-loaded draw schedules (expensive land funded at closing) push the factor toward 0.65; back-loaded finishes pull it toward 0.45.

For the permanent phase, ordinary amortization math applies — our jumbo payment calculator handles it instantly.

Sizing the whole project budget

• Total project cost = land + hard construction costs + soft costs (design, permits, fees) + contingency (5–10%) + construction interest (estimated above) — lenders size the loan against this full figure.
• Your equity requirement = total cost × (10–30% depending on scale and program), with owned-land value counting toward it.
• The interest-reserve decision: financing the construction interest inside the loan preserves cash flow during the build at the cost of a slightly larger final balance — model both.
• The qualification test: lenders qualify you on the eventual full payment (P&I on the final balance, plus taxes and insurance on the completed value) — run that number early; it is the binding constraint more often than the down payment.

A project penciled on all four lines before design work begins never produces the heartbreak version: finished plans for an unfundable house.

From estimate to term sheet

These methods get you within a few percent — close enough to set a design budget and test feasibility honestly. The precise version comes from a lender term sheet built on your actual draw schedule, rate quote, and timeline, and it is worth getting before architectural money is spent: an hour with real numbers reshapes projects cheaply on paper that would reshape expensively in permits. We prepare that feasibility picture — construction interest, equity requirement, eventual payment, and qualification check — as the first deliverable on every construction file. NMLS# 1967971.

Quick answers

Why is my lender's interest estimate higher than the formula's?

Lenders often model conservative draw schedules and full construction periods — prudent padding. Your actual bill follows actual draws; the formula approximates the middle.

Should I include the land in the interest estimate?

If the loan funds the land at closing, yes — it is drawn from day one and accrues the whole period, which pushes the average-balance factor up.

How do I estimate the eventual payment before locking a rate?

Use a rate band, not a point — your realistic quote range across the build window — and confirm you qualify at the top of it. That is how lenders will stress it too.