About Mountainside Houses
Only about 7,300 people live in Mountainside, across four square miles. Nearly nine homes in ten are owner-occupied, the typical household has close to three people, and the census median value for an owned home is a little over $800,000. Rentals are uncommon enough that the census tops out its rent estimate at "$3,500 or more." For a long-time owner of a single-family house here, the question is not whether it will sell but whether you want to spend months and money getting it ready.
- 7,346residents estimated for July 2025 (7,020 in 2020)
- 87.9%share of homes lived in by their owners (ACS 2020–2024)
- $810,300median value, owner-occupied homes (ACS 2020–2024)
- 4.00square miles of land
Source: U.S. Census Bureau QuickFacts, Mountainside borough, New Jersey.
A Mountainside house still with its first owner usually has original systems somewhere: a boiler, a roof layered over an older roof, a kitchen from another era. Houses like that are what we buy. Our written figure reflects comparable Mountainside sales and the work we expect to do afterward.
The One Certificate Mountainside Asks For
The borough's building department page is direct about it: the smoke detector resale and re-leasing certification is "the only document the Borough of Mountainside requires for sale of a home." It is a residential-only inspection, requested online through the SDL Portal, with a $100 fee. After payment the borough assigns an inspection date, and inspections run Tuesday afternoons from 3 to 6 and Thursday afternoons from 1:30 to 4:30.
The inspector checks the items in the state fire code. Smoke alarms belong on every level and outside each sleeping area; any battery-only alarm has to be a ten-year sealed unit, and a hard-wired system that came with the house cannot be swapped for battery units. Carbon monoxide alarms, which can be battery, plug-in or hard-wired, go near the bedrooms.
One wrinkle: the same page still links an application for a Certificate of Continued Occupancy, also $100, whose checklist goes further, naming railings, roof layers, water, sewer, the sump pump and every permit taken out on the house. The borough's current wording says the alarm certificate is the only sale document, but before closing it is sensible to confirm with the construction office at 908-232-2919 which inspection applies to your address. When we buy, we make that call, book whatever is needed and deal with the outcome. Open permits from an old project are a common find in long-held houses, and closing them out is part of our work, not a cost you pay before settlement.
Mountainside Taxes and Sewer Fees
The borough's tax collector bills both property taxes and sewer fees. Reconciled tax bills are mailed once a year in early July, the four quarters fall due on Feb. 1, May 1, Aug. 1 and Nov. 1, and the grace period covers the first ten calendar days of each quarter. Payments can be mailed, dropped in the lock box in the Borough Hall lobby on Route 22, made in person or paid online; a postmark does not count as on time.
In 2025 Mountainside's general rate was 2.100 per $100 of assessed value and its effective rate was 1.566, among the lowest in Union County. If you have fallen behind, the payoff is simply deducted from the price at closing, including any lien already sold at a tax sale. The tax lien guide covers the steps if a certificate holder has gone to court.
Utilities, Vacancy and Higher-Priced Homes
The borough lists American Water for water, Elizabethtown Gas, and both PSE&G and Jersey Central Power & Light for electricity, so final readings may come from more than one company depending on your street. We ask for each one a few days before closing.
Mountainside's vacant property ordinance (No. 1303-2021) is aimed at lenders: it requires a creditor to register a vacant and abandoned property, name an agent and a maintenance firm, and pay $500 at first, rising to $5,000 a year by the third renewal. It is one reason a house that stalls in foreclosure can become expensive for everyone involved.
Where a Mountainside house is priced at $1 million or more, the state's graduated percent fee, charged to sellers since July 10, 2025, starts at 1% of the price. Our offer shows that fee next to the realty transfer fee and every other cost, so the figure you see is the figure you keep.
Estates, Downsizing and Foreclosure
Three kinds of Mountainside sale come up for a cash buyer. Executors settling a parent's estate get their authority from the Union County Surrogate (908-527-4280), and we can wait for it. Owners ready to downsize can leave behind furniture and anything else they do not want to move. Owners behind on a mortgage have until the Union County Sheriff's sale to sell, and state law gives them ten business days to cancel a contract with us. See downsizing in New Jersey and selling an inherited house.
How the Sale Works
- Send the address and a short description of the house and your timing.
- A single visit, then a written price, typically the next day.
- Once you agree, we open title and request the borough's certificate through the portal.
- Close at a New Jersey title company or attorney's office, or sign remotely with a notary, on your date.
Mountainside is in Union County. We also buy in nearby Springfield and Westfield.
The borough's senior services office (908-232-4406) runs meal delivery and a senior van and helps residents with the state's PAS-1 property tax relief form. Central Jersey Legal Services takes Union County calls at (908) 354-4340 for eligible residents. Both are worth contacting before you decide to sell.