House Hacking

House hacking describes buying residential property that provides more space than the buyer needs, living in part of it, and renting the remainder so that the tenants' rent offsets the owner's housing cost. In practice it usually means buying a two-, three- or four-unit building and occupying one unit, though renting rooms in a single-family house or an accessory dwelling unit is the same idea at smaller scale.

No agency or statute uses the phrase, which is worth saying plainly: it is a name the market gave to an arrangement, not a defined product. The mechanics underneath it are defined, though, and they are the reason the arrangement is interesting. Mortgage programs price loans by occupancy, and a one- to four-unit property that the borrower will live in is financed as a residence rather than as an investment property. That single classification, rather than the rent itself, is what separates house hacking from simply buying a rental.

Start with the financing, because that is the part a landlord who does not live in the building cannot get. Owner-occupied mortgages accept smaller down payments and price better than investment-property loans, and the eligibility extends across one to four units rather than stopping at a single dwelling. So the same fourplex can be financed two entirely different ways depending on whether the buyer intends to move into one of its units. The rent from the other units is a second benefit rather than the primary one, and lenders will often count some of it toward qualifying, which compounds the effect.

FHA states three constraints that decide whether the plan is workable, and all three are in Handbook 4000.1. The first is occupancy: "At least one Borrower must occupy the Property within 60 Days of signing the security instrument and intend to continue occupancy for at least one year." The second closes the obvious loophole, and it is written broadly: "FHA will not insure a Mortgage if it is determined that the transaction was designed to use FHA mortgage insurance as a vehicle for obtaining Investment Properties, even if the Property to be insured will be the only one owned using FHA mortgage insurance." Intent is part of the test, so a borrower who never means to live in the building is not merely bending a formality.

The third applies only to the larger buildings and is the one that most often ends a plan. For three- and four-unit properties the handbook requires a self-sufficiency test. It defines Net Self-Sufficiency Rental Income as "the Rental Income produced by the subject Property over and above the Principal, Interest, Taxes, and Insurance (PITI)," sets the standard that "the PITI divided by the monthly Net Self-Sufficiency Rental Income may not exceed 100 percent for three- to four-unit Properties," and prescribes the calculation: take the appraiser's estimate of fair market rent from all units, "including the unit the Borrower chooses for occupancy," and subtract the greater of the appraiser's estimate for vacancies and maintenance or 25 percent of fair market rent. In an expensive market where prices have risen faster than rents, a triplex frequently cannot pass. Note also that both two-unit and three- to four-unit purchases require form HUD-92561, the Borrower's Contract with Respect to Hotel and Transient Use of Property. Treat all of this as Handbook 4000.1 policy by section rather than as timeless law, since the handbook is revised section by section.

The tax side changes the moment a tenant moves in, and it changes in two directions. The rented portion is a rental activity, so the rent is rental income and the property's costs have to be allocated between the owner's personal use and the rental use. The favorable half is that the tenants' share of mortgage interest, property taxes, insurance, utilities, repairs and depreciation becomes deductible against that income, which is not true of the owner's own unit. The unfavorable half arrives at sale: the exclusion of gain on a principal residence does not cover depreciation allowed or allowable on the rented portion, whether or not it was actually claimed, and the classification rules that decide how a mixed-use dwelling is treated are their own subject. What matters at the planning stage is knowing that a house hack is two properties on one deed for tax purposes.

The costs that do not appear in the arithmetic are the ones worth naming. The owner is a landlord living on site, which means the repairs, the vacancies, the tenant screening and the disputes all arrive at home. The building is a single, undiversified, illiquid asset carrying a larger mortgage than the owner's own housing need would justify, and a vacancy is a direct hit to the household budget rather than to a portfolio's income. None of that argues against the arrangement, and all of it belongs in the comparison against renting or buying a smaller place.

The buyer finds a one- to four-unit property, qualifies for owner-occupied financing on it, closes, moves into one unit within the period the program requires, and rents out the rest. From then the property is simultaneously the owner's home and a rental, and it is reported that way.

A hypothetical self-sufficiency test. Ana is buying a triplex with an FHA loan. The appraiser's fair market rents are $1,500, $1,500 and $1,400 a month, including the unit Ana will occupy, so total fair market rent is $4,400. The appraiser's vacancy and maintenance estimate is $900, but 25 percent of fair market rent is $1,100, and the calculation takes the greater of the two. Net Self-Sufficiency Rental Income is therefore $3,300 ($4,400 minus $1,100). The standard requires the PITI to be no more than 100 percent of that figure, so the payment on Ana's loan must be $3,300 or less. If the quoted PITI is $3,650, the property fails and Ana must reduce the loan amount, find a different property, or use different financing.

A hypothetical cash comparison. Ana instead buys a duplex with a PITI of $2,900 and rents the second unit for $1,750. Her out-of-pocket housing cost is $1,150 a month ($2,900 minus $1,750), against $1,900 to rent a comparable one-bedroom nearby, a difference of $750 a month. Two things keep that from being the whole picture. The $1,750 is rental income and is taxable, offset by the rental share of the property's expenses and depreciation. And the $2,900 is a fixed obligation while the $1,750 is not: a three-month vacancy costs her $5,250 with the payment still due.

Pros

• Owner-occupied financing on a one- to four-unit property is materially cheaper and requires less cash down than investment-property financing on the same building.
• Rent from the other units offsets housing costs directly, which is the largest line in most household budgets.
• The rental share of interest, taxes, insurance, repairs and depreciation becomes deductible, which is not true of an ordinary home.
• It is a route into property ownership for a buyer who could not fund an investment purchase separately, and it builds landlord experience at small scale.

Cons

• The owner lives with the job. Repairs, tenant disputes and turnover are next door rather than at a distance.
• The self-sufficiency test on three- and four-unit FHA purchases can rule out the property in exactly the markets where the arithmetic looks best.
• A vacancy hits the household budget directly, and the mortgage is larger than the owner's own housing need would justify.
• The property is a single illiquid asset in one location, concentrating both the housing and the investment in one place.
• Tax reporting becomes materially more complex, and depreciation allowed or allowable on the rented portion is not covered by the principal-residence gain exclusion at sale.