Mountainside, NJ Real Estate Guide: Buy, Sell & Rent

Mountainside is a Union County borough of 7,020 residents as of the 2020 Census and covers about four square miles. Nearly a third of the borough is parkland, most of it in the Union County-run Watchung Reservation, and Route 22 runs across its southeastern side. Housing here is overwhelmingly single-family. Here's what to know before you buy, sell or rent in Mountainside.

Why People Choose Mountainside

Open space is a big part of the appeal. The Watchung Reservation covers more than 2,000 acres of woodlands, fields, lakes and streams with more than 13 miles of hiking trails, bridle paths and Lake Surprise. Union County's Trailside Nature and Science Center sits inside the reservation at 452 New Providence Road in Mountainside. On the other side of town, Echo Lake Park offers about 139 acres with two lakes, ball fields, a dog run and the Union County 9/11 memorial.

Access to highways is the other draw. Route 22 crosses the borough and Interstate 78 runs along its northern edge, so drivers can reach Newark, Newark Liberty International Airport and points west without long local drives.

Getting Around: Commuting from Mountainside

• Bus: NJ Transit routes 114 and 117 run to the Port Authority Bus Terminal in Manhattan, and routes 65 and 66 serve Newark. Route 95 also serves the borough.
• Train: Mountainside has no train station of its own. The closest options are Westfield and Garwood on the Raritan Valley Line and Summit and New Providence on NJ Transit's Morris & Essex Lines, with Summit offering direct trains to New York Penn Station.
• Car: Route 22 and I-78 connect the borough to the Garden State Parkway, the New Jersey Turnpike and the rest of North and Central Jersey.

Neighborhoods and Housing Types

Union County's borough profile describes Mountainside as largely residential. More than 95 percent of its homes are single-unit detached houses, and about half were built before 1960. Census estimates put the owner-occupancy rate at about 88 percent. What you'll find:

• Single-family homes: The vast majority of the housing stock, ranging from mid-century homes to newer construction.
• Two-family and multifamily homes: A small share of the market, including a handful of apartment buildings.
• Route 22 corridor: The borough's commercial frontage. Mountainside has adopted inclusionary overlay zoning along Route 22 that permits multifamily housing at up to 12 units per acre with an income-restricted set-aside, which may add apartment options over time.

Buying a Home in Mountainside

Because single-family homes dominate, Mountainside buyers are usually comparing houses of different ages, sizes and lots. Here's what we help them check:

• Older-home inspections: With much of the housing built before 1960, a careful look at the roof, foundation, drainage, electrical, plumbing, heating and any older oil tank is essential.
• Location within town: Homes near the reservation, near Route 22 and in between each have their own appeal. We help you weigh access to trails and parks against commute routes.
• Flood status: We check FEMA flood maps for any home near a stream or low-lying area before you make an offer.
• Property taxes: We pull the current tax figure for every home you're considering so you can budget accurately.
• Multi-unit properties: They're rare here, but if you find a two-to-four-family property, an FHA loan can work with a low down payment as long as you live in one of the units.

We can connect you with a lender for pre-approval before you start touring, and we work with cash buyers too.

Selling Your Mountainside Home

With a limited number of homes and few non-single-family alternatives, each Mountainside sale is measured closely against nearby comparable houses. Age, updates, lot and location within the borough all affect price. We'll prepare a free comparative market analysis using truly similar recent sales and market your home across the MLS and major online channels to reach buyers looking throughout Union County.

Renting and Investing in Mountainside

Rentals are a small part of Mountainside's housing, and most are single-family homes or units in the borough's few apartment buildings. We help renters find what's available and help owners price, market and screen tenants for a home they plan to lease. For investors, we'll look at realistic rents, taxes, insurance and condition before you commit.

Local Landmarks and Amenities

• Watchung Reservation, including Lake Surprise, the Sierra Trail and the Watchung Riding Stable on Summit Lane
• Trailside Nature and Science Center
• Echo Lake Park and the Echo Lake Park Fitness Trail behind Borough Hall
• The Levi Cory House, built around 1818, and the Deacon Andrew Hetfield House at Constitution Plaza, preserved by the Mountainside Restoration Committee
• Mountainside Public Library and Mountainside Community Pool
• AMC Mountainside movie theater
• Public schools: Mountainside School District, with high school students attending Governor Livingston High School in Berkeley Heights

Nearby Town Guides

Comparing Mountainside with nearby towns? Read our guides to Westfield, Springfield, Berkeley Heights and Scotch Plains, or browse all of our North Jersey town guides.

Talk to a Local Broker

The Thompson Realty Group is a licensed New Jersey real estate brokerage based at 20 MacArthur Ave in Garfield, serving buyers, sellers, renters and investors across Bergen, Essex, Hudson, Passaic and Union counties. Whether you're a first-time FHA buyer, a cash investor, or a homeowner wondering what your place is worth, we'll give you straight answers about Mountainside.

Call or text 201-928-5562 or book a free 15-minute consultation. You can also search every active New Jersey listing on our website.

Information on this page is provided for general guidance and is believed accurate as of October 2026. Programs, ordinances, taxes and transit schedules change, so please verify details for any specific property. Equal Housing Opportunity.