How Boise's Minor Land Division Incentive Can Save You $30K and 18 Months on Your Next Infill Deal

If you're looking at infill land in Boise, there's a good chance you've priced out the standard subdivision process — and a good chance it scared you off. Multiple hearings. A planning and zoning commission vote. City council approval. Full civil engineering. Two and a half to three years before you're anywhere close to done.

There's a faster way, and it's sitting inside Boise's own zoning code: the minor land division.

What a Minor Land Division Actually Is

Boise used to let you split up to four lots through a standard administrative process — no hearings required. When the city rewrote its zoning code, they pulled that option unless you qualify for one of their affordability incentives.

Qualify, and instead of a full subdivision working its way through commission hearings and city council votes, your split gets handled as an administrative-level decision. You still have to meet most of the same requirements as a subdivision, but with meaningfully less engineering and less back-and-forth with the city.

On a deal I walked through recently, that difference showed up immediately: the property already had an attached sidewalk, but Boise's updated code requires new detached sidewalks on every new home — meaning even an existing sidewalk normally has to be torn out and replaced. On a minor land division, you can typically keep it. That alone saves about $11,000 in hard costs on this one property.

Stack that with roughly $20,000 in soft-cost savings — less engineering, fewer agency reviews — and you're into the project for about $30,000 less than a standard subdivision, with an approval timeline that drops from roughly a year down to about six months. Add in a shorter infrastructure buildout, and a project that would normally run two and a half to three years can come in at 18 months to two years instead.

How to Actually Qualify

The minor land division isn't automatic — you have to hit one of Boise's affordability incentive thresholds. There are two main paths:

If you're building to sell: One of the units has to be marketed to a buyer at or below 120% of the area median income for their household size. That threshold moves depending on whether it's a single buyer or a family, so there's some judgment involved in how you structure the sale.

If you're keeping units as rentals: Only one of the units needs to qualify as affordable — meeting 80% of the area median income for rent. For 2025, that works out to a household making no more than roughly $62,000 a year, with an affordable rent around $1,550 a month.

The move that makes this incentive pencil without sacrificing profit: build a smaller, efficient unit — for example, a one-bedroom ADU around 550–600 square feet — priced at that $1,550 rent point. New-construction one-bedrooms in the area are already renting close to $1,500, so you're not giving up meaningful rent to hit the affordability requirement. You get the incentive, and you're not leaving money on the table.

What This Looks Like On an Actual Deal

Here's how the math plays out on a real property: a completed flip on an R2 lot, priced right at market, split into an existing home plus two new townhome lots.

Underwritten as a full subdivision, this deal pencils to roughly $115,000 in profit over 2.5 years, with a total out-of-pocket around $238,000 (25% down, entitlements and horizontal development paid up front). That's a 1.48x equity multiple and roughly a 20.5% annualized return.

Route it through the minor land division instead, and entitlement costs drop from about $51,000 to roughly $30,000 — while the timeline compresses toward 18–24 months. $30k more profit, delivered faster, which almost doubles the annualized return .

There's also a cash-recycling piece worth knowing about: once the new plat is recorded, you can sell the existing home on the property and recover a meaningful chunk of your original down payment before the new construction even starts. And when you go to build, a construction loan refinance can often return most — sometimes nearly all — of your remaining hard and soft costs, since you own the land free and clear at that point. Underwritten conservatively (assuming none of that cash comes back early), the deal still works. Any of it coming back early is upside.

One More Lever: Boise's Updated ADU Rules

Worth flagging separately, because it changes what "one lot" can actually produce: Boise now allows any single-family lot to add up to two ADUs, as long as they physically fit and still meet all the setback requirements. On a subdivided lot like the one above, that opens the door to stacking a garage on the ground floor with two ADUs above it — three stories total. Do that on both new lots, and a property that started as a single door can support up to nine units.

That's not a variance or a special approval. It's the code, as written, today.

The Bottom Line

The minor land division isn't a loophole — it's a deliberate lever Boise built into its zoning code to encourage affordable unit production. For infill development investors, it's one of the more direct ways to cut both cost and timeline without changing the fundamentals of a deal that already pencils. The catch is that qualifying for it requires structuring the deal correctly from the start — unit size, pricing, and AMI thresholds all have to line up before you break ground.

We underwrite every deal that goes on our list— so you can see exactly what each route does to your numbers before you commit capital. New deals go up every Friday.