New subdivisions keep pushing east into Ammon and north toward Iona and Ucon as Idaho Falls grows. For investors, the steady demand from INL and regional employers makes build-to-rent twin homes, duplexes and spec homes a practical way to add rental supply.
In short: LendingStreet finances ground-up construction of 1-8 unit investor properties in Idaho Falls, Ammon, Iona, Rigby, Shelley and Rexburg, including spec homes, build-to-rent homes, twin homes, infill duplexes and fourplexes, and small 5-8 unit buildings. Loans are sized on loan-to-cost with terms set per project, and funds are released through a draw schedule after inspections. Plans, permits, a detailed budget and an experienced builder are expected.
Build-to-rent twin homes and side-by-side duplexes are common in Ammon and Iona, where newer subdivisions have lots zoned for attached homes. Spec homes for resale are popular in the same areas and in Rigby. Infill fourplexes and small apartment buildings appear on multifamily-zoned lots in Idaho Falls.
In Rexburg, some investors build with student or family rentals in mind; plan the design around how the property will be leased.
Rental demand in the area is steady because of Idaho National Laboratory, its contractors, the regional medical center and retail employers. New two- and three-bedroom units with garages tend to lease well to families and professionals relocating for those jobs. Designing for that tenant, rather than for luxury finishes, usually keeps budgets and rents in line.
Eastern Idaho's frost depth means deeper footings, and many new homes include full or daylight basements, which add finished space at a lower cost per square foot. Basement units for rent need egress, ceiling height and separate systems to be legal dwellings.
Soil and groundwater vary across the valley. Lots near the Snake River or canals may have higher water tables, which affects basement design. A soils report helps the budget.
Daylight basements on sloped lots give natural light and an easier path to a legal basement unit, but most Idaho Falls lots are flat, so egress window wells are the norm. Plan them into the foundation design rather than cutting them in later.
Many Idaho Falls area subdivisions include pressurized irrigation from canal systems, with assessments that carry over to the owner. Confirm water, sewer and irrigation hookups and fees before closing on the lot. Cities in the area charge building permit and connection fees, which belong in soft costs.
Irrigation water is a real advantage for landscaping in a dry climate, but the delivery system needs to be installed and inspected with the rest of the site work. Coordinate early with the irrigation district or HOA that manages it so lawns and trees can go in before the first lease begins.
This example is illustrative and not a quote. An investor buys an Ammon lot zoned for twin homes for $98,000. Hard costs for two attached homes with unfinished basements are $485,000, and soft costs (design, engineering, permits, connection fees, insurance) are $52,000, for a total project cost of $635,000.
At an assumed 80% loan-to-cost for this example, the loan is $508,000 and the investor's equity, including the lot, is $127,000. When finished, each side is expected to rent for about $1,750, or $3,500 a month combined, supporting a DSCR refinance or a sale of each side separately where lots are split.
Splitting the lot so each side is its own parcel also gives you the option to sell one side and keep the other.
| Draw stage | Share of hard costs | Amount |
|---|---|---|
| Excavation, foundation and basement walls | 20% | $97,000 |
| Framing, roof and windows | 30% | $145,500 |
| Mechanical, electrical, plumbing | 20% | $97,000 |
| Insulation, drywall, finishes | 20% | $97,000 |
| Final inspection and occupancy | 10% | $48,500 |
Excavation and foundations are easiest from spring through fall. Many builders aim to frame and dry in before heavy snow, then finish interiors over winter. Wind is a factor in eastern Idaho, and roofs and framing need to be secured.
Winter heating during drywall and finish work is a cost to budget.
Wind and dust are a regular part of eastern Idaho building sites, especially on the open lots at the edge of town. Secure materials, protect framing and plan for dust control where the city requires it. Those small items help avoid damage, delays and complaints from neighbors in occupied subdivisions.
Funds are released after an inspector confirms each stage. Keep enough cash on hand to pay subcontractors between draws. Our draw schedule calculator at /construction-draw-schedule-calculator.html helps map payments to your build.
Plan draw requests around inspection availability, which tightens in the peak summer season across Bonneville County.
Most investors sell or refinance into a DSCR loan. Budget taxes on full assessed value with no homeowner's exemption; the first full assessment after completion may be noticeably higher than the lot assessment. New construction usually insures more affordably than older homes.
If you plan to sell, price the finished homes against recent new-construction sales in the same subdivision. If you plan to hold, get a rent estimate during planning so you know the refinance can clear 1.0x at the leverage you want.
Plans and permit status, a line-item budget, your builder's license and project history, a construction schedule, the lot deed or contract, utility and irrigation confirmations, entity documents and proof of equity and reserves. Projects without plans or permits, or a borrower with no build track record and no experienced general contractor, usually do not qualify.
A builder with recent projects in Bonneville County, current insurance and references from local suppliers strengthens the file. First-time builders usually need an experienced general contractor on the project.
Our investor loans are business-purpose loans on non-owner-occupied property. Send the lot address, plans, budget and timeline through the form below or call (877) 298-1001. See our Idaho construction page for statewide guidance.
Yes. Twin homes and duplexes are common investor builds in Ammon and Iona.
On loan-to-cost: land plus hard and soft costs, with terms set per project.
Yes, if it is designed as a legal dwelling unit with egress and code-compliant systems, and zoning allows it.
They are an ongoing owner cost in many subdivisions. Confirm them before buying the lot.
Interior work can continue. Foundations and framing are easiest before the ground freezes.
Approved plans or permits well along in review are expected.
If the lot is legally split and each side is its own parcel. Confirm with the city.
Most investors sell or refinance into a DSCR loan based on the new rents.
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