The Mobile Home Park Operator's Model
Version 1.0 · Updated July 2026 · Instant download · Excel, Google Sheets, LibreOffice and Numbers
An eighteen-sheet mobile home park acquisition model in Excel. It runs fifteen Fannie Mae and Freddie Mac eligibility tests before you write a letter of intent, counts park-owned home income three ways, prices the utility configuration as an expense line rather than waving at it with a cap-rate bump, and stress-tests infill by fifty per cent by default.
Why this exists
In January 2009 someone on Mobile Home University’s forum offered to share a simple spreadsheet he used to underwrite parks. He never posted it. Roughly fourteen different people asked for it over the following fifteen years — “Where is the spreadsheet?” in May 2015, “Please share the spreadsheet” in August 2018, “could you please send spreadsheet to me, also?” in May 2024. One of them wrote that he had received it in 2018 and could no longer find the file.
Meanwhile the category authority’s own Excel model is not sold separately. It comes bundled inside a boot camp costing upward of $1,700.
Will this park finance? Fifteen tests, before the LOI
A first-time buyer usually discovers the financing problem at week six of due diligence, after the earnest money is at risk and $15,000 of third-party reports have been ordered. Sheet 10 answers it in four minutes.
| Test | Requirement | Source |
|---|---|---|
| Minimum pad sites | 50 (Fannie) / 5 (Freddie) | Both term sheets — a park that fails Fannie may still be Freddie-eligible |
| Park-owned homes | ≤25%, up to 35% with a documented reduction plan | Fannie MHC term sheet |
| Density | ≤12 homes/acre existing, 7 new | Fannie |
| Economic vacancy assumption | Minimum 5%, regardless of actuals | Fannie |
| Max LTV / min DSCR | 80% / 1.25x | Both |
| Sponsor | MHC operating experience — the test that stops most first-time buyers | Both |
| Lease restriction | No tenant pad-purchase option in 2yr+ leases | Fannie |
The mobile home park model vs. a generic proforma
- Park-owned homes counted three ways — lot rent only, gross less a haircut, or full gross — with the value of the choice shown in dollars, defaulting to how a lender does it.
- The utility configuration priced: master-metered, private well and septic, or on-site treatment plant. A treatment plant runs $40–$60 per lot per month plus a capital reserve at least equal to the operating cost plus $1,000,000+ to replace. Every source asserts private utilities discount valuations; none quantifies it, so this model prices it instead.
- The submetering case with the fee everyone forgets — third-party billing at $3–$8 per site per month, running against your recovery forever.
- Infill with a 50% delay stress test on by default, and the present-value cost of that delay.
- The Rolfe check and the ×70 rule on the face of the sheet.
Where the seller’s price comes from
The model ends with a list. Six ordinary, defensible-sounding choices, each with a dollar figure against it. On the $2,450,000 sample they total $2,616,680 — capitalising the full home rent instead of the lot-rent equivalent, capitalising the whole rent gap rather than half, capitalising late fees, using the seller’s tax bill, no management fee because the seller runs it, and no capital reserve. That is arithmetic you can put in front of a broker.
Who this is not for
It does not model ground-up development, a mid-hold refinance, or a partnership waterfall. It does not attempt rent-to-own or lease-option conversion of park-owned homes, which implicates SAFE Act and Dodd-Frank seller-financing rules outside its scope. And utility billing law is state-specific and moving fast — the model lists what was found and flags all of it as secondary-sourced. Pull the statute.
What is in the box
Buy on Gumroad → · Or run the free financing gate first →
Version history
| v1.0 | 28 July 2026 — first release. 18 sheets, 1,706 non-empty cells, 66 verification checks, zero formula errors. |
Questions
What is the best mobile home park underwriting model I can buy?
There are four options. A $75–$99 tier of generic marketplace models cross-listed across several sites; Alpine CRE at $197; this one; and the category authority's model, which is not sold separately and only comes bundled with a boot camp costing upward of $1,700.
Is there a free mobile home park underwriting model?
There are four free web calculators, and none is an institutional-grade multi-year Excel model. Adventures in CRE, which publishes free models for seventeen other property types including RV parks, has never built one for this asset class. The best free tool tops out at a three-year projection with no infill, no park-owned-home conversion, no utility recovery and no reversion — one of them says so on its own page.
Will this model tell me whether a park can get agency debt?
Yes. Sheet 10 runs fifteen tests against the published Fannie Mae and Freddie Mac term sheets with the citation next to each, returning pass, conditional or fail. It also distinguishes between the term sheet and the credit box: Freddie's term sheet allows private wells and septic with considerations, while seller-servicers in practice require municipal sewer. Both are true, and the gate shows both.
How should park-owned home income be counted?
At the lot-rent equivalent, which is how most banks do it — they underwrite lot-based income and lot-based expenses, both sides. This model counts it three ways and defaults to lot rent only, then carries the home business as a separate profit and loss below the NOI line so the home premium and the home repair cost stay together. Counting only lot income while charging full home costs is a mistake in the other direction and it is just as wrong.
What expense ratio should a mobile home park run at?
It depends on two things, so the model uses a matrix rather than a cell. Roughly 30% where tenants pay their own water and sewer, 40% where the park pays, and 40% and 50% respectively for a park under 20 lots. By home ownership: tenant-owned-dominant parks run 30–35% and park-owned-heavy parks run 55–65%, a thirty-point swing. UMH Properties, the one audited comparable at roughly 41% park-owned homes, reported 41.9% in 2024.
How long does mobile home park infill actually take?
Two to three years, per an operator with more than fifty parks, who also warns that underwriting assumptions typically underestimate completion timelines by fifty per cent or more. No source publishes a monthly absorption rate. This model ships a fifty per cent delay stress test switched on by default and prices what the delay costs in present value.
Does it model a partnership waterfall?
No. The deal-level returns are the input to your waterfall, not a substitute for it.
Does it work in Google Sheets?
Yes. INDEX, MATCH, SUMPRODUCT, COUNTIF, OFFSET, MIN, MAX, IRR and IFERROR only.
Is there a refund policy?
Yes. Email runbooksupply@gmail.com.