Union County

Union County checks in at a 3.06% cap rate and a gross rent-to-price ratio of 0.047, which puts it squarely in appreciation territory rather than cash-flow territory. At a $641,174 median purchase price against $2,515 in median monthly rent, the numbers don't pencil for an income-first buyer financing at 6.85%. The model underwrite produces a monthly mortgage of $3,361, estimated expenses of $880, and an estimated cash flow of negative $1,726 per month, resulting in a cash-on-cash return of negative 14.04% on a $128,235 down payment. Year-over-year home price growth sits at 1.15%, modest in absolute terms but consistent with a market where prices are already high enough that entry-level appreciation compounds meaningfully. An affordability index of 14 out of 100 confirms this is a deeply unaffordable market for owner-occupants, which tends to sustain rental demand but does nothing to help the investor's purchase economics.

The investor profile this county suits is narrow: an appreciation buyer with patient capital and ideally some ability to offset carry costs through value-add repositioning. The cash-on-cash return is negative enough that no reasonable rent bump closes the gap under current financing conditions. A buyer would need either a substantially below-market acquisition, a significant rent premium on a renovated unit, or a long enough hold horizon to let appreciation and eventual mortgage paydown do the work. The overall score of 43 out of 100, with a cash-flow score of 41 and appreciation score of 62, confirms the same picture the raw numbers tell. This is not a market where you buy for monthly income; it's a market where you hold for equity, assuming you can stomach the carry.

On carry costs, the tax burden alone deserves its own line in any underwrite. New Jersey's state-average effective property tax rate is 2.49%, and at that rate on a $641,174 purchase, annual property taxes run approximately $15,965, or roughly $1,330 per month. Combined with an estimated $112 monthly in insurance, total tax and insurance comes to $1,443 per month. That single line item alone represents more than half the monthly rent collected. The propertyTaxFlag here is "very_high," and that designation is warranted: very few markets in the country impose this level of carrying cost as a percentage of value. The caveat from the data applies directly: this is a state-average effective rate sourced from Tax Foundation 2024, and actual county or township rates in Union will vary, potentially materially. Underwrite conservatively and pull actual assessed values and municipal rates for any specific municipality before committing.

Demographically, Union County's population of 572,079 provides scale that limits single-employer or single-sector concentration risk relative to smaller markets, but the affordability index of 14 signals that the pool of potential owner-occupants who can buy their way out of renting is thin. That dynamic sustains rental demand structurally, though it also reflects the broader New Jersey cost burden that has historically pressured population retention among younger renters. The county ranks 721st out of 1,000 nationally and 20th out of 21 New Jersey counties in overall investment score, placing it at the 8th national percentile. That ranking is a clear signal that this is not a generalist buy-and-hold market; it's a market for a specific thesis.

Compared to its neighbors, Union's case gets harder to make. Hudson County carries a higher overall score (48 vs. 43) at a lower median price ($617,352 vs. $641,174) and a meaningfully better rent-to-price ratio of 0.057 vs. Union's 0.047. That spread is not trivial: Hudson's gross yield is roughly 20% higher, which, at these price points, translates to several hundred dollars per month in rent relative to acquisition cost. Passaic County scores 51 overall, comes in at $574,942 median price, and matches Union nearly dollar-for-dollar on rent-to-price (0.048 vs. 0.047), while being roughly $66,000 cheaper to enter. Essex County, at a 47 overall score and $635,686 median price, offers a slightly better rent-to-price than Union at 0.044. Monmouth County and Cape May County both score lower on rent-to-price, so they don't improve the income picture. The case for choosing Union over Hudson or Passaic requires a specific neighborhood thesis, a belief in superior appreciation, or a property-level value-add angle that compensates for the worse county-level yield profile. On the numbers alone, Hudson and Passaic present better starting points for most buy-and-hold investors evaluating northern New Jersey.