06-reference/research

temp housing rent dti construction perm

2026-08-25·research-brief·source: deep-research·by Ray Data Co (deep-research synthesis)

Temp-Housing Rent and DTI: the Agency Answer Is No, the Premise Behind the Question Is Wrong, and the Real Exposure Is an Overlay

The question

Verbatim: "Does 12-18 months of temporary-housing rent count as a monthly obligation in DTI on a single-close construction-to-perm where the subject property is the borrower's future primary residence?"

Context: this is a derivative follow-up from [[2026-08-19-jumbo-construction-perm-qualifying-envelope]]. That brief budgeted temp housing as a cash line in sources-and-uses (~$108k) and not as a DTI line. If it is also a DTI line, the qualifying table in that brief does not shrink, it inverts.

⚠️ THE BACKLOG NOTE'S PREMISE IS FALSE. The queued question asserted that "Fannie B5-3.1 addresses treatment of the borrower's current housing expense during the construction period." It does not. I fetched both B5-3.1-01 (Overview) and B5-3.1-02 (Single-Closing Transactions) and neither section mentions the borrower's current housing, rent, temporary housing, or where the borrower lives during construction. The answer does not live in B5-3.1. It lives in B3-6-05, and it lives there by omission rather than by rule.

What we already know (from the vault)

What the web says

Convergences and contradictions

Synthesis for RDCO

The parent brief's table survives, on the agency baseline. Under Fannie's rules as written, a borrower whose subject property will be their principal residence is charged the subject PITIA in DTI and nothing else for housing. Interim rent between vacating the teardown and occupying the new build is not an enumerated monthly obligation, and the one provision that names rental housing payments is scoped to non-occupant borrowers and non-primary subject properties. That is the correct default assumption and the qualifying-envelope table in [[2026-08-19-jumbo-construction-perm-qualifying-envelope]] does not need to be rebuilt.

The stakes if a lender overlays it are not marginal, they are terminal, and it is worth stating the arithmetic plainly. Deriving from the parent brief's own stated inputs (combined gross $325,000, a 43% DTI test, non-housing debt $1,516/mo, escrow $4,200/mo): monthly qualifying capacity is $11,646, leaving $5,930 for P&I after debts and escrow. Charge $8,000/mo of rent against that and the remaining P&I budget is negative by roughly $2,070. This is not a scenario where the envelope shrinks and a smaller build still pencils. If a lender counts the rent, the loan does not exist at any build size, at any rate, with any escalator. That asymmetry is the reason this question deserved its own brief and the reason it should be asked of every lender in the first conversation rather than discovered at underwriting.

Because the exposure is binary and the agency text is silent, the correct posture is to buy insurance rather than to argue the guide. The cleanest mitigation is already sitting in the budget: the ~$108k temp-housing line is being paid in cash regardless. Prepaying the lease term at signing, or structuring it as a paid-in-advance or month-to-month arrangement with no outstanding contractual obligation at the note date, removes the monthly-payment characteristic that any overlay would attach to. Same dollars, same house, no DTI line to argue about. The secondary mitigation is sequencing: the parent brief's strongest recommendation was already to apply in mid-2027 rather than Q1 2027 to clear the 12-month bonus-seasoning line, and a mid-2027 application also means the lease question is being negotiated with a file that has more income cushion to absorb a bad answer.

One caution on how this gets used. I have not verified what any specific Florida portfolio construction lender does here, and I did not find a lender-program document addressing it. There is a plausible alternative treatment worth testing but explicitly unverified: some construction lenders handle interim living costs as a reserves requirement (prove you can carry rent plus construction-period interest) rather than as a DTI line. That would be a materially better outcome than a DTI charge and a materially worse one than nothing, and it would interact badly with TD's already-known 10%-of-construction-cost reserve hold. Do not assume it, ask it.

Why this is in the vault

It resolves the highest-severity open follow-up from [[2026-08-19-jumbo-construction-perm-qualifying-envelope]] — the one that could have zeroed out that brief's entire qualifying table — and it converts an untested assumption in the home-rebuild-2027 sources-and-uses (that temp housing is cash, not debt) into a cited position with a named failure mode and a specific mitigation. It also gives the founder a concrete first-call question for every Florida construction lender on the shortlist in [[2026-08-14-construction-to-permanent-loans-florida]], where a wrong answer discovered late costs the whole application cycle.

Open follow-ups

Related

Sources

Vault

Web (primary sources, all fetched directly)

Verification caveats

Research caps: 1 QMD query (one additional attempt failed on the hyphen-negation parse and was not retried), 2 WebSearch, 3 WebFetch. Within the 5 / 3 / 3 template caps.