What does a buyer actually get with a century-old house in Mountain Lakes? The listing shows bedrooms, baths and a lot size. It does not say whether the house still qualifies for a borough zoning bonus. That bonus lets a qualifying historic house, plus its garage, pool and terrace, take up more of the lot than any new house built there after a teardown would be allowed.
The bonus comes from the borough's historic-preservation incentives ordinance, which passed on July 23, 2012 and was amended on March 27, 2017. It is voluntary and does not order anyone to preserve anything. In the borough's own words, owners stay "as free as they were prior to the ordinance to renovate, expand or demolish their home in accordance with existing zoning restrictions." The town pays for preservation in buildable square footage, and only houses that stay eligible can collect it. Changes a past owner made to the house decide whether a buyer can still use it.
The Bonus, In Square Feet
Most of Mountain Lakes' older housing sits in two residential zones. The borough's standard bulk table, Schedule I of Chapter 245, sets these baselines. In Zone R-AA the minimum lot is 22,500 square feet, with a 13% floor-area ratio and 20% improved lot coverage. In Zone R-A the minimum lot is 15,000 square feet, with a 17% FAR and 25% coverage. Both zones require 25-foot side setbacks.
A house that qualifies under the 2017 amended ordinance gets higher limits. R-AA rises to 16% FAR and 24% coverage. R-A rises to 21% FAR and 30% coverage. Side setbacks in both zones drop to 20 feet, as long as the two sides add up to at least 50 feet.
Here is what that means on a lot at each zone's minimum size:
| Zone and lot | Standard floor area | Incentive floor area | Standard improved coverage | Incentive improved coverage |
|---|---|---|---|---|
| R-A, 15,000 sq ft | 2,550 sq ft | 3,150 sq ft | 3,750 sq ft | 4,500 sq ft |
| R-AA, 22,500 sq ft | 2,925 sq ft | 3,600 sq ft | 4,500 sq ft | 5,400 sq ft |
On an R-A lot of that size, the difference is about 600 square feet of floor area. On an R-AA lot it is about 675. The figures are illustrative. The borough FAQ says certain spaces don't count toward FAR, and it advises owners to work out their home's actual FAR with an architect or builder. The direction holds either way. On the same lot, a qualifying historic house can legally get larger than a new house built after a teardown, and it can do so without a variance.
The Bonus Reaches The Pool And The Garage
A buyer looking at the house alone can underestimate the bonus. The ordinance says a qualifying property gets "the full benefit of the Bulk Incentives" for all zoning purposes. That includes improvements "unrelated to the contributing dwelling (including but not limited to accessory structures, garages, swimming pools, terraces and driveways)." The bonus also counts when the borough works out how large any variance request would need to be.
Improved lot coverage is often the limit that blocks a pool, a wider driveway or a detached garage. Raising it from 25% to 30% in R-A, or from 20% to 24% in R-AA, makes room for those projects. Even a buyer who never plans an addition is paying for that room when the house qualifies.
What Keeps A House Eligible
The bonus follows the house, and the house's renovation history decides it. Under the ordinance, a property qualifies only if every alteration made after the Bulk Incentives Effective Date meets a set of design rules. For houses the National Register form calls Hapgood or Belhall structures, that date is August 11, 2012. For all other contributing dwellings it is April 1, 2017.
The rules in Section 40-49B require the following:
- Changes to street-facing facades must be compatible with the original structure, including the proportions of doors and windows.
- Side additions on the primary street-facing facade must sit back at least 12 inches from the facade plane, and their rooflines at least 12 inches from the existing roofline.
- The original roof ridge, pitch and overhangs must stay, and new dormers must match the house's typical dormer styles.
- Replacement windows need real or simulated divided lights, with grille patterns, sizes and shapes that suit the original.
- All of the primary street-facing facade's width and height must remain intact.
- At least 75% of the original floor area as it stood on December 31, 1938 must remain.
The borough FAQ states the consequence plainly. Alterations made after the ordinance that are "out of character with the historic nature of the home" can keep an owner from using the incentives later, even if those alterations never used the bonus. A 2015 window replacement with no divided lights, or a side addition built flush with the front of the house, may already have cost a property its bonus before it ever came on the market.
There is a way back. Section 40-49B(5) lets an owner ask the Zoning Board of Adjustment to approve past or future alterations that don't strictly comply, on the recommendation of the Historic Preservation Committee, if the board finds them compatible. Approved work counts as if it were done before the effective date. Work approved for the future has to start within one year of final approval. That route runs through a board hearing, so it takes time.
Checking eligibility is up to a licensed architect, who signs a checklist and certification form as part of the construction permit application. The borough posted an updated version of the architect checklist dated April 2, 2025.
Which Houses Are On The List
The houses go back to the town's founding years. Herbert J. Hapgood built on a plan he developed with local engineer Lewis Van Duyne, and the first family moved into 46 Dartmouth Road on March 17, 1911, according to the borough's history page. The historic district's National Register form from 2005 is the basis for eligibility today.
There is a gap between the borough's documents. The Historic Preservation FAQ still describes the first version of the ordinance. It says a house must be a Hapgood or Belhall built before 1932, and that "over 490 homes currently meet this definition." The 2017 amendment is broader. It defines a contributing dwelling as one built on or before December 31, 1938 and listed as a "contributing building" in the National Register form. The borough can also add other houses by ordinance on the recommendation of the Committee and the Planning Board. A house from the 1930s that isn't a Hapgood may qualify even though the FAQ's description leaves it out.
The published list of contributing dwellings gives each house's address, construction year and Hapgood, Belhall or other designation. It was last updated on December 12, 2019. The list itself warns that its construction years come from the 2005 National Register form, may be inaccurate, and may need checking against title records. A house that hovers near the 1938 cutoff can turn on a date in a deed.
What A Teardown Gives Up
Buyers who plan to replace the house face a different process. Before the borough issues a demolition permit for a contributing dwelling, the owner must deliver notice to the Historic Preservation Committee, in person at Borough Hall or by certified mail. The notice describes the planned demolition and timing and includes proof of a nonrefundable $500 payment. A 90-day notice period starts on the day the notice is delivered.
The notice period can't stop a demolition. According to the FAQ, it gives the owner a chance "to learn about the benefits that will be lost" and lets the house be documented for the historical record. Once the documentation is done and the period ends, the owner is entitled to the permit. The new house then falls under the standard limits in the table above: 13% or 17% FAR, 20% or 25% coverage, and 25-foot side setbacks. The bonus is gone for good, because a demolished house no longer meets the definition of a contributing dwelling.
That changes the math on a teardown. A buyer pricing an older house as land value pays for the lot and then gives up the bonus once the house comes down. A buyer who keeps a qualifying house can add space up to the higher limits, provided the street facade and at least 75% of the original 1938 floor area remain.
The borough treats this heritage as a public asset beyond private homes too. In July 2026, Morris Focus reported that the Mountain Lakes Train Station, a contributing property in the district and an active stop on NJ Transit's Montclair-Boonton Line, received a $126,000 Morris County Historic Preservation Trust Fund grant for more exterior restoration.
A Note On Price Data
Public town-level sales figures for Mountain Lakes covering the third quarter of 2026 were not available as of early October 2026, and quarterly samples here can be as small as ten sales. With so few sales, a median can't show whether a given older house still qualifies for the bonus. The ordinance and the house's alteration record show that.
FAQ
Does the ordinance change property taxes? The borough says it doesn't. Taxes rise only if improvements made under the ordinance raise the property's value, the same as with any other improvement.
Can an owner of a historic house renovate without any special approval? Yes. Alterations remain subject only to the existing construction and zoning rules. Work that is out of character with the house can still affect whether it qualifies for the bonus later.
Who decides whether a planned change is compatible? The owner's licensed architect makes the first call through the certification form. Owners can also ask the Zoning Board or Planning Board for clarification in advance.
If you are considering an older Mountain Lakes house, Luxe Home Concierge can help you gather its contributing-dwelling status, its permit history since 2012 and an architect's eligibility review before you make an offer, then manage the renovation to the ordinance's standards and keep the records in your Luxe Home Vault. Schedule your Luxe consultation.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
