What Is NOI and How Do Mobile Home Park Owners Calculate It Correctly?

Net Operating Income is the most important number in mobile home park investing. It drives valuation, determines your lender’s approval decision, anchors your cap rate analysis, and — when the time comes to sell — is the number buyers will scrutinize to set their offer price.

Yet NOI is routinely miscalculated by new MHP owners and improperly presented by sellers trying to make their parks look more attractive than they are. The errors are often not intentional — people simply include the wrong items or exclude the right ones because nobody explained the definition clearly.

This post explains NOI from the ground up: the full calculation from Gross Scheduled Income down to the final NOI number, what belongs in each line, what absolutely does not belong, and how NOI relates to (but differs significantly from) taxable income.

The NOI Calculation: Step by Step

Step 1: Gross Scheduled Income (GSI)

Gross Scheduled Income is the total income your park would generate if every rentable unit were occupied at its scheduled rent. This is a theoretical maximum — it assumes 100% occupancy at current lease rates.

For an MHP, GSI includes:

• Lot rent from all lots — including vacant lots, at the current market rent rate
• POH rent from all park-owned homes — including vacant POHs, at current market rent
• Utility income — if the park bills tenants for water, electric, gas, or sewer, include the gross billings (not net of the park’s utility cost)
• Other regular income — storage fees, laundry income, late fees, pet fees, amenity fees

Note that vacant lots and homes are included at market rent — not zero. GSI represents the scheduled rent, not the collected rent. The adjustment for vacancy comes in the next step.

Step 2: Vacancy and Credit Loss

Subtract vacancy and credit loss from GSI to get Effective Gross Income. Vacancy has two components:

• Physical vacancy: Lots or homes that are unoccupied. Calculate as: (number of vacant units / total units) × scheduled rent for those units.
• Economic vacancy (credit loss): Rent owed but not collected — tenants in arrears, bad debt write-offs, non-paying tenants in eviction. This is a separate reduction from physical vacancy.

For an MHP, lot rent should have very low physical vacancy (lots are inexpensive relative to apartments, and lot rent is typically much lower than alternative housing). POH rent typically carries higher vacancy and credit loss because POH tenants are more financially vulnerable than lot-lease tenants who own their own homes.

Step 3: Effective Gross Income (EGI)

EGI = GSI minus vacancy and credit loss. This is the income the park actually expects to collect based on current occupancy and collection history.

Step 4: Operating Expenses

Operating expenses are the costs of running the park. The key rule: operating expenses are recurring, cash-based costs of operation. They do not include debt service, depreciation, or capital expenditures.

Standard MHP operating expense categories:

• Property management: The cost of managing the park, whether paid to a third-party manager or imputed at market rate for self-management. Typically 5-10% of EGI depending on park complexity.
• Property taxes: Annual real and personal property taxes assessed on the park.
• Insurance: Property and liability insurance premiums.
• Utilities: Master meter costs for utilities that the park pays directly — water, sewer, trash, electric for common areas. If the park sub-bills tenants for utilities, include both the cost (as an expense) and the recovery (as income in GSI). Do not net them — gross presentation is standard.
• Maintenance and repairs: Routine maintenance, landscaping, snow removal, minor repairs. Ongoing, recurring costs of keeping the park operational.
• Administrative: Accounting, legal, software, office expenses.
• Reserves (sometimes included): Some underwriters include a capital expenditure reserve as an operating expense. This is not universal — many NOI calculations exclude reserves and address CapEx separately. Know which convention your buyer or lender is using.

Step 5: Net Operating Income (NOI)

NOI = EGI minus Total Operating Expenses.

This is the number. It represents the income the park produces from operations before any financing costs, taxes, or depreciation. It’s the number buyers and lenders use as the foundation for every calculation that follows.

What Does NOT Belong in NOI

The errors that inflate or deflate NOI are almost always about including or excluding items that don’t belong. Be explicit about these:

Debt service (mortgage payments) does not belong in operating expenses. NOI is calculated before financing. The fact that you have a $5,000 monthly mortgage payment is your business — not a determinant of what the park earns. Different buyers will have different financing, and the asset’s income should be evaluated independently of how any individual buyer finances the acquisition.

Depreciation does not belong in operating expenses. Depreciation is a non-cash tax deduction that reduces taxable income — it has no effect on cash flow or the actual cost of running the park. Including depreciation in operating expenses produces a number that is far below the park’s actual cash operating income.

Capital expenditures do not belong in operating expenses. Replacing a road, overhauling a water system, or doing major improvements on park-owned homes are capital expenditures, not operating expenses. They should be accounted for separately in a CapEx analysis — not deducted from NOI. Including a large one-time CapEx item in operating expenses artificially suppresses NOI in the year the expense occurred.

Income taxes do not belong in operating expenses. NOI is a pre-tax metric. Your personal or entity income tax liability has nothing to do with the park’s operating performance.

How NOI Is Used for Valuation

Valuation of a mobile home park is primarily driven by this formula:

Value = NOI / Cap Rate

If the applicable market cap rate for parks in your area is 7%, and your park has $140,000 of stabilized annual NOI, the indicated value is $2,000,000 ($140,000 / 0.07).

The leverage in this formula is enormous. At a 7-cap, every additional $7,000 of verifiable NOI adds $100,000 to your value. At a 6-cap, the same $7,000 of NOI adds $116,667. This is why getting NOI right — both the calculation and the documentation — is the highest-value work a selling MHP owner can do before listing. See our post on cleaning up your books before listing for the full process.

How Lenders Use NOI: The DSCR Calculation

When a buyer applies for a loan to purchase your park, the lender will calculate the Debt Service Coverage Ratio (DSCR) using NOI and the proposed annual debt service payment:

DSCR = NOI / Annual Debt Service

Most commercial lenders require a DSCR of at least 1.20x to 1.25x — meaning NOI must be at least 20-25% higher than the annual debt service. A lower DSCR means the park’s income provides insufficient cushion above the mortgage payment, and lenders will either reduce the loan amount, require a larger down payment, or decline the loan.

For buyers using agency financing (Fannie Mae, Freddie Mac for manufactured housing communities) or SBA programs, DSCR thresholds and expense load requirements may differ. The lender will typically underwrite NOI independently — using their own vacancy assumptions, expense loads, and management fee estimates — rather than accepting the seller’s NOI at face value. Clean, well-documented financials that can defend the seller’s NOI claim against the lender’s scrutiny is what protects deal pricing.

How NOI Differs From Taxable Income

This is the concept new MHP investors find most confusing: a park can have strong NOI (a cash metric) while simultaneously showing a taxable loss on the owner’s tax return. These are not contradictory — they measure different things.

NOI excludes depreciation. Taxable income includes depreciation. For an MHP with significant personal property (POHs on 5-year MACRS) and cost-segregated land improvements, annual depreciation can easily exceed the park’s taxable cash flow in early years of ownership. The result: strong NOI from operations, but a taxable loss that offsets the owner’s other passive income.

The owner is not actually losing money — they’re generating cash flow and simultaneously receiving a non-cash tax deduction. This is the fundamental tax efficiency of MHP investing. But it only works if you keep the two metrics clearly separate in your thinking and reporting. Presenting taxable income as NOI — or confusing the two — produces a wildly wrong picture of the park’s economics.

For more on how depreciation and passive losses interact, see our post on passive vs active income classification for MHP owners, and for the full tax advantage picture, see how MHP tax characteristics compare to other asset classes.

FAQ

For HUD guidance on manufactured housing community standards and definitions, see HUD Manufactured Housing and Standards.

Internal links: Cap Rate vs Cash-on-Cash Return | Clean Up Your Books Before Listing | Passive vs Active Income Classification

Disclaimer: This post is for educational and informational purposes only and does not constitute tax, legal, or financial advice. NOI conventions vary among lenders and buyers; always confirm the specific convention being used in any transaction. Tax laws change and individual circumstances vary. Consult a qualified tax professional before making any investment or financial decisions regarding mobile home parks. The MHP Accountant® is an enrolled agent firm; engagement of professional services is required for personalized advice.