Mobile Home Park Zoning: Underwriting Nonconforming Use

Published October 22, 2026

Clark County, Washington, has 34 manufactured home parks housing more than 2,000 residents, per July 2026 reporting by the Camas-Washougal Post-Record on a county council workshop, and the county is rewriting the rules that govern them. It adopted a moratorium on redeveloping existing parks in August 2025 and has renewed it through February 2027, per KATU's reporting. A July 15, 2026 draft of a new Manufactured Home Park Overlay District (Clark County Code 40.250.120) would limit redevelopment while, in the draft's words, "allowing the continued repair, replacement, and expansion of manufactured housing in accordance with the standards of this title."

That is one county, and zoning is local. But it points at a line item that rarely appears in a broker's offering memorandum and almost never in a seller's trailing 12-month statement: whether the jurisdiction allows the thing the buyer is paying for today, and whether that is about to change. A park sitting in a zone that no longer lists the use is commonly a legal nonconforming use — allowed to continue, but often not to expand or rebuild.

Why mobile home park zoning decides whether an infill thesis is real

Infill is the core value-add lever in a mobile home park (MHP), and it comes in two forms that nonconforming status treats very differently.

Re-letting a lot that was part of the park's originally established count is generally a continuation of the existing use. The pad, the utility stub, and the setback were approved decades ago, and bringing a home back onto it typically does not require new entitlement. Adding lots — a new row along the back fence, a strip of adjacent acreage brought into the park — is an enlargement of the use. In a jurisdiction that no longer permits MHPs in that zone, enlargement commonly requires a rezone, a conditional use permit, or a variance, any of which may take months and may not be granted.

A pro forma that blends both into a single "stabilize to 95% occupancy" assumption hides that split. The lot-by-lot infill model is the right frame, but it only works if each lot in it is legally lettable. Figures in this section are illustrative; the governing rule is whatever the local code and a zoning verification letter actually say.

What the agency guides require on nonconforming status

The sourced facts, separate from the interpretation that follows.

• Delivery condition on a nonconforming use. Fannie Mae's Multifamily Selling and Servicing Guide, Part II, Chapter 3, Section 301.02, requires a lender on a legal non-conforming use property to ensure the borrower executes modifications to the loan and security agreement and to confirm, following a casualty, the percentage of damage to the improvements — the destruction threshold. The section states that if the destruction threshold is less than 50%, the lender is not to deliver the mortgage loan.
• Nonconforming characteristics. Section 301.03 requires the lender to confirm whether the improvements can be fully rebuilt if destroyed, to evaluate whether the as-rebuilt property would support the loan at its current tier, to consider the sufficiency of estimated proceeds from ordinance or law insurance, and to document the analysis in the transaction approval memo.
• Density guidance. Fannie Mae's manufactured housing community chapter sets a minimum of 50 sites and, in its quality rating standards, describes maximum density as generally 12 sites per acre at Level 3 and generally seven sites per acre at Level 4, or 10 per acre if developed before 2000.
• Setbacks on the survey. The same chapter asks that the survey identify setbacks imposed by applicable zoning ordinances or building codes, and contemplates a statement that zoning setbacks apply only to permanent buildings rather than to the manufactured homes themselves.
• Reserves. Fannie Mae requires full funding of the replacement reserve where the property condition assessment determines more than $75 per site, against a minimum annual amount of $25 per site. Freddie Mac's Multifamily Seller/Servicer Guide, Section 22.2(i), sets $50 per home site per year and $250 per borrower-owned home per year, with the actual amount determined after Freddie Mac reviews the consultant's assessment. Freddie Mac's Section 22.6(b)(6) separately asks the lender to confirm that the installation of the homes complies with all zoning and building codes.

Guide requirements change by bulletin and are applied with lender discretion, so the current text is worth confirming directly with the lender rather than relying on any summary, including this one.

What this could mean for the deal: a worked example

What follows is a read of the rules, not a prediction about any specific park. The 80-lot park below and its figures are illustrative planning assumptions and are not drawn from a transaction.

An 80-lot park, predominantly tenant-owned and direct-billed, with 62 lots occupied at roughly $450 a month in lot rent. Gross lot rent runs roughly $335,000, and in-place Net Operating Income (NOI) lands near $210,000 on an expense ratio in the high-30s, priced at about $3.0M at a 7.0% cap rate. The seller's pro forma carries two infill legs: re-let the 18 vacant established lots, and add 12 new lots on two adjacent acres already inside the parcel. Both legs assume the same $450 lot rent, or $5,400 a lot per year. The example assumes roughly 75% of new rent flows to NOI on re-let lots, whose pads, roads, and utility stubs the park already carries, and roughly 65% on new lots, which add their own utility, road, and upkeep costs.

The second leg assumes roughly $35,000 per lot of pad, utility, and road cost, or about $420,000 — a yield on cost of roughly 10% if it gets permitted, and a write-off of the entitlement work if it does not. Softening that leg to zero takes roughly $600,000, or about 20% of price, out of the business plan without changing a single operating assumption.

The density guidance can bite the same leg from the other direction. Adding 12 lots on two acres is about six per acre on the new ground, which may sit inside the Level 4 range above, but a tighter layout designed to make the cost work could push the as-built plan past where the pro forma assumes it would rate.

The casualty and exit problem nobody models

The destruction threshold is where nonconforming status stops being a development question and becomes a financing one. If the local ordinance says the use may not be re-established once damage exceeds, say, 40% of value, that sits below the 50% figure in Fannie Mae's Section 301.02 — and on the guide's own language, the loan is not deliverable.

That has two effects worth pricing. The first is today's debt: a deal underwritten to agency pricing may need to clear at a bank or bridge quote instead, which generally changes both coupon and proceeds. With the 10-year Treasury near 5.27% as of October 6, 2026, per the Federal Reserve's H.15 release, the spread between an agency execution and the alternative is not a rounding error, and the Debt Service Coverage Ratio (DSCR) test tends to bind before the leverage test does — the same mechanic covered in the DSCR-constrained agency post.

The second is the exit. A buyer in year five faces the same delivery condition, which narrows the pool of financeable bidders and can show up as a wider exit cap rate rather than as a disclosed zoning problem. Ordinance or law insurance is the usual partial answer, and Section 301.03 asks the lender to weigh whether its estimated proceeds are sufficient — but coverage limits are negotiated, and a policy that rebuilds the improvements does not restore a use the code no longer allows.

Where this breaks

Three places, honestly.

First, nonconforming does not mean impaired. A great many long-established parks are nonconforming and trade, finance, and refinance without incident, because the ordinance permits the use to continue indefinitely and nothing ever forces the question. Treating nonconforming status as a repricing event by default would overstate the risk and lose deals that work. The variables that matter are the damage threshold, the abandonment or discontinuance period, and whether the business plan depends on enlargement.

Second, Clark County is one jurisdiction in one state, and its overlay and park standards were drafts at the time of writing. They are useful as evidence that counties are actively rewriting these rules — the companion July 2026 standards draft (Section 40.260.140) states that no minimum density applies to manufactured home parks — not as a national pattern. Reading Clark County's direction into any other market would be unsupported.

Third, a code rewrite can cut the other way. A jurisdiction that brings parks into a conforming zone may unlock expansion rights that were unavailable at acquisition. Clark County's draft overlay, which says its standards would supersede the base zone standards, is one example of a rewrite aimed at preserving parks rather than restricting them. An underwriting that prices only the downside of entitlement may miss an option that costs nothing to hold.

The Bottom Line

Mobile home park zoning is an underwriting input, not a legal footnote. The two questions that carry real dollars are whether the pro forma depends on adding lots rather than refilling them, and what the local damage threshold does to agency deliverability at acquisition and at exit. Both are answerable before closing, with a zoning verification letter, an as-built survey showing setbacks, and the property condition assessment read together — and both are far cheaper to answer then than in year three. The MHP due diligence checklist and the broader park underwriting framework cover where these items sit in the wider process.

UWmatic is an AI-powered underwriting platform built for multifamily and mobile home park investors. Split the infill plan into lots you can refill and lots you would have to entitle, then see what the second group is worth at your exit cap rate before the zoning letter comes back. Try the free underwriting calculator →

This analysis reflects current market interpretations as of the publication date and may evolve as new data becomes available. Agency requirements are drawn from Fannie Mae's Multifamily Selling and Servicing Guide (Part II, Chapter 3, Sections 301.02 and 301.03, and the manufactured housing community chapter) and Freddie Mac's Multifamily Seller/Servicer Guide (Sections 22.2(i) and 22.6(b)(6)); the Treasury yield is from the Federal Reserve's H.15 release; the Clark County park count is from July 2026 Camas-Washougal Post-Record reporting, the moratorium dates are from KATU's reporting, and the quoted overlay language and density standard are from Clark County's July 15, 2026 drafts of Code Sections 40.250.120 and 40.260.140, which may change before adoption. The 80-lot park, its rents, costs, and value effects are illustrative and are not drawn from a specific transaction. Zoning is determined locally and agency guide requirements change by bulletin — verify current terms directly with the jurisdiction and the lender before relying on any figure above. Nothing in this post is investment advice; readers should conduct their own diligence and consult qualified professionals before making investment decisions.