Proposed Princeton zoning ordinance has unintended consequences

By Marina Rubina

“We Are Fully Built-out” Ordinance # 2019-2

On Monday 02/25 the Princeton Council will hold a public hearing about the proposed ordinance eliminating Proportional or Adjusted Floor Area Ratio (F.A.R.) for undersized lots. This ordinance is being proposed to “maintain neighborhood character.” It has not been mentioned, however, that the maximum allowed home sizes will be reduced below the size of many existing homes. Making a large portion of existing buildings “non-conforming” may help discourage tear-downs, but it will also prohibit additions, require a zoning variance for every exterior modification and effectively designate the center of town “completely built-out”.

Brief background: 

  • Floor Area Ratio is the total area of a building divided by the area of the lot on which it is built expressed as a percentage.
  • Maximum allowable F.A.R is a common zoning tool for controlling the size of development.
  • The town has been divided into zones loosely based on density: smaller lots in the center and larger lots further away.
  • The F.A.R. is higher in the center of town to allow reasonably sized structures to be built on smaller lots and becomes smaller as the lots get larger.  
  • Unfortunately, Princeton’s zones do not correspond to the existing fabric of neighborhoods, creating many “undersized” lots. There are often whole neighborhoods located in zones where the required lot size is twice the size of a typical lot.
  • The current zoning code for many years has included a “proportional or adjusted F.A.R.” formula to help alleviate problems created by overlaying suburban zoning over denser neighborhoods.

To provide a real life example, I gathered data from the tax assessor’s office for two streets: Western Way and Leigh Avenue. Both of these streets are at the border of former Township and Borough and have visually consistent neighborhood character. The data included 101 homes, 97 of which are on undersized lots, most of them about half the required size. 

I have graphically represented the data. Some notes about the graphs:

  • The orange area shows the existing F.A.R., while the blue indicates the maximum allowed F.A.R., including the proportional/adjusted formula;
  • The blue area above the orange area indicates the “area of opportunity” — additions or possibly larger homes that could be built under the current zoning rules;
  • In many cases the existing homes already exceed the maximum allowed size (built before current zoning);
  • The red line indicates the “base F.A.R.” without the proportional adjustment. This will be the new maximum if the ordinance passes on Monday.

It is clear from the data that the new ordinance will reduce the allowable size of structures below what is already built. Although this may be viewed by some as a great deterrent to tear-downs, it will have the following consequences:

  1. Since most of the homes on these undersized lots will be deemed “too large,” no additions will be possible.
  2. Making existing buildings on undersized lots “non-conforming” will trigger the need for a variance for all exterior alterations, such as changing a window. The backlog at the zoning board AND financial impact on homeowners with the smallest/undersized lots is hardly fair or desirable;
  3. This rule will make practically all buildings in the center of Princeton too large; thus, declaring the center of town fully built-out.

By declaring our town fully built-out, the council is sending a clear message that we are already the best we can be, leaving no room for improvement. Is this the Princeton of the Future we want?

Princeton just hired a new staff planner. Could we not rush this ordinance full of unintended consequences, and let the new planner take a fresh look? Could we set goals and let him suggest updates to the zoning code to better reflect our existing neighborhoods AND plan for the future? Several ideas came out of the work done by consultants in the Neighborhood Character study in 2017-18. There was a proposal to create a sliding scale for F.A.R. based on the actual lot area. Or, possibly something similar to Lawrence township’s linking size of homes to prevailing homes in the neighborhood.

As we think about what “Princeton of the Future” will look like, I hope we agree that maintaining neighborhood character is important, but we also desperately need to improve our town’s walkability, sustainability and affordability. Passing an ordinance that declares the town center built-out hardly seems like the right solution.


  1. An ordinance that causes so many Princeton homes to fall out of compliance with existing zoning is, to be kind, not smart. At best it’s disingenuous.

    Any change anyone would want to make would require a variance. This would lead inevitably to concerns about the equitable application of rules, not to mention the necessity of coming up with rules that could be equitably applied.

    And just making it harder to build a “McMansion” — which this ordinance probably would do a good job of hindering — wouldn’t do ANYTHING to solve the problem of the growing unaffordability of homes in Princeton to “regular” families…the so-called “Missing Middle” problem.

    A sustainable town is not one that forces low and middle income employees to drive long distances to get to work.

    You can compost as much as you want – you can post a “we’re happy you’re our neighbor” sign…but it’s toothless if all the teachers, police, barristas, librarians, waitstaff, retail staff, nannies, cleaners, and lawn maintenance workers have to drive 20-30 miles each way to get to work because they can’t afford a home here.

    This ordinance is just more of the exclusionary infrastructure that Princeton’s elected officials seem intent on erecting in the name of “preserving town character.”

  2. Agree with Nat. This is just another example of the elitism of the mayor and the council. See Witherspoon-Jackson historic preservation as another example.

  3. This is a very well-researched analysis by a professional architect who has dedicated her career to improving developed environments. She and we who walk (and bike) around Princeton have realized a truth – that higher FAR in proximity to Central Business Districts creates neighborhoods and character. It’s also good for the environment requiring fewer automobile trips as we allow more people to live closer to town and transit.

    This “solution” is something from the 1960’s School of Sprawl and should be rethought, seriously. Our Mayor and Council can do a lot better.

  4. Thank you for this careful analysis. This ordinance sounds like a disaster for Princeton. Although most residents are probably blissfully unaware of this possibility, they will be furious if the ordinance passes (much like the poorly thought out parking meter debacle). I hope the council does the right thing for Princeton and votes this down.

  5. I like and respect fellow architect Marina Rubino, and often agree with the insights she brings to land use issues in Princeton, but in this instance, I have to disagree with her point of view. First of all, when she warns of onerous zoning relief needed for interior renovations or simple exterior maintenance, this is not the case. It could reasonably have been inferred from the originally introduced language of the ordinance, but there was a clause subtracted accidentally, which has been added back in, clarifying the protection of the rights of pre-existing structures to be altered in any way which does not increase the non-conformity of the building.

    Secondly, her interpretation of the original reason for the FAR bonus allowance does not make sense to me – she claims it was to “help alleviate problems created by overlaying suburban zoning over denser neighborhoods.” But the denser urban neighborhoods she analyzes comprise their own zone – R4 exists only in the center of town. If the framers of the original ordinance had simply wanted to permit higher densities here, they could have accomplished this easily just by increasing the FAR in the zone. While we do not have a record of why they handled it the way they did, it seems much more likely to me that they were trying to ensure that houses on uniquely undersized lots in a neighborhood of conforming lots would not be dwarfed by their neighbors and appear out of place. This rationale has no benefit in neighborhoods where large numbers of lots are undersized.

    Thirdly, while the neighborhoods she chose to analyze do have many structures that exceed the “base FAR”, we have many other areas in town where the lots are consistently undersized, the houses are very modest and do not even come up to the base FAR. These are neighborhoods which have been particularly plagued by tear-downs, with erection of completely incongruous developer houses that take advantage of the bonus FAR, dwarf their neighbors and disrupt the fabric of the town. Linden Lane, Wheatsheaf Lane, and Ewing Street are a few examples.

    Keep in mind that many of the houses Marina identifies, particularly on Western Way, come right up to, and in some cases exceed the bonus FAR, so these homes, in order to make further additions would be in need of variance relief whether we change the bonus FAR provision or not.

    Finally, the notion that this ordinance change creates a situation wherein Princeton will be built-out, without potential for further development to enhance walkability, sustainability and affordability is far-fetched. Princeton Future has identified upwards of 20 locations in town ripe for redevelopment which can accommodate many truly urban apartment-style residential units which will fill the need for affordable, walkable, sustainable dwellings much better than enlarged single family homes, which do nothing to further these goals.

    This ordinance will actually enhance the value of existing large homes on undersized lots, since a replacement after tear-down would wind up having significantly less floor area. Thus it will effectively curtail tear-downs, conserve the embodied energy in these older structures, and encourage preservation and restoration in the affected areas, exactly what we should be striving for in the Witherspoon-Jackson neighborhood. Otherwise, why did we go to all the trouble to create our newest historic district here, just a couple years ago?

    Any change in the rules that govern a community will create winners and losers. I don’t deny that there are some home owners looking to enlarge their homes who will be disadvantaged by this rule change, but the large majority of residents who like the size home they live in and like the neighborhood they live in will benefit from this ordinance.

     Councilman David E. Cohen

  6. Thank you for the clear explanation, Rubina. As a realtor I too was disturbed by the oversized new homes in some traditional neighborhoods, but found that the solutions in the new propoed zoning and the historical designation of WJ hurting the very people who were already offended by megasizing new construction. let us work to find a better way.

  7. David- why do we want to curtail tear downs? Isn’t there demand for new construction? You and your fellow council members are infringing upon the property rights of taxpayers. Yes, some zoning is needed, for setbacks and water management. But you’re going far beyond that and if you pass this ordinance, you will be communicating that Princeton is closed for new construction, thereby removing any hope to spread the increasing tax burden on increased valuations that come from new construction. And what happened in the WJ neighborhood is reason enough to table this ordinance.

  8. Princeton’s leaders seem to have decided that we don’t want to keep up with modern needs. That’s fine for current residents, but 20-30 years down the road, when we wonder how the town got passed by, being only a town for the rich or university-connected to live in, it will be because of such well-meaning regulations.

    Already, it seems that the only only businesses in town are restaurants frequented by the ever increasing university crowd (see the announcement of two more residential colleges that will be built). Witherspoon Street is now almost wall-to-wall with restaurants to the library. The restaurants are great, but what happens to the regular businesses that citizens need? They are moving to the Shopping Center or out of town completely.

    Let’s prevent environmentally destructive new homes, but allow new buildings to be built, even if they don’t look like the Victorian homes from the last century. Personally, it would be both socially responsible and financially rewarding to tear down my Victorian home and replace it with a multi-family building. The probable outcry from my neighbors keeps me from even mentioning the idea, but that’s why we have an affordability crisis in town.

  9. I wrote the original article because I believe good policy decisions are made when information is clearly presented, allowing the public and government officials to evaluate the pros and cons of options available.

    This ordinance is rushed, and unintended consequences are not fully thought out. There are multiple ways of dealing with the problems of larger homes going up next to small ones that not only have fewer side effects, but also allow us as a community to move forward to our goals of sustainability, walkability and affordability.

    In response to your points:

    1. You said that “when she warns of onerous zoning relief needed for interior renovations or simple exterior maintenance, this is not the case. It could reasonably have been inferred from the originally introduced language of the ordinance, but there was a clause subtracted accidentally.” The corrections were made precisely BECAUSE local professionals, including my original article, pointed out the unintended consequences. By bringing the staff’s attention to the fact that “the sky is falling” we were able to prevent at least this chunk of the sky from falling;

    2. I can elaborate on why I think the adjusted FAR helps alleviate problems created by overlaying suburban zoning over denser neighborhoods.

    • My guess is that when original zoning ordinance was written in the 60’s (?) it was done with the long-term vision of what “Princeton of the Future” should look like. That vision was spelled out by setting minimum required lot size in the borough to be 6,000 sq.ft.(R4) and 6,500 sq.ft. (R9) in the township, translating into density of about 7 dwelling units per acre.

    • I read this as exclusionary zoning typical of the time, written to benefit people of means. Only well-off people can afford to buy large lots. There was no zone with small lot size in the code to reflect the reality and the need for such neighborhoods as Witherspoon Jackson, because they were “non-conforming” to the vision.

    • The section we are currently debating included 2 provisions: first one (that was accidentally deleted in #1 above) states that if you have an existing non-conforming condition, as long as you don’t make things any more non-conforming, it is ok to keep what you have. The second one included the adjusted/proportional FAR formula allowing more reasonable size home on these tiny lots.

    • Both of these provisions helped the town alleviate the backlog of cases that would have flooded the zoning board with minor changes that people on undersized lots needed to make to their homes.

    It is possible that this section saved the denser and more affordable neighborhoods from being wiped out by the overlay of low density, suburban zoning. This section allowed these neighborhoods to remain and develop even though they were marginalized in this “non-conforming” state.

    3. If I have time on Monday to get the information from the tax office and analyze it before the Council meeting, I will do so for the streets you mentioned: Linden Lane, Wheatsheaf Lane, and Ewing St. For now, let’s consider the example of 141 Linden Lane – all information is publicly available via real estate websites.

    • lot area is 7,841 sq.ft., and the required lot in this zone, R8-township, is 8,500 sq.ft.
    • there was a 1950-s single story home on the property of about 1,300 sq.ft.
    • the home was expanded/rebuilt(?) in 2016 by a developer to its current size of 2,337 sq.ft.
    • Using the base FAR, the maximum allowed house size would be 2,352 sq.ft.
    • Using the adjustment formula for undersized lots, the maximum area of the home could be increased by 182 sq.ft.
    • Surprisingly, the house was either not “maxed-out” or the extra floor area went toward the garage that is located in the back of the home.

    It will be more clear with the analysis for the entire street, but my sense is that the new homes on Ewing and Linden look so shockingly bigger because the “area of opportunity” between the existing 1,300 sq.ft single story homes and base zoning of 2,352 sq.ft. is very large. The removal of the adjusted formula would have done nothing to prevent this tear-down or others like it. It could have made a very minor reduction in the size of the new home, or possibly not allowed them to have a garage.

    You mention that “any change in the rules that govern a community will create winners and losers.” I am glad we are having this discussion. It is important to understand who the losers are and whether the loss imposed on them is worth the gain to the community. To me, reducing the size of new homes on Linden Ln. by 180 sq.ft. is not worth putting a huge number of people in a position of having to get variances.

    Going back to point #2, zoning is the law that puts forth our vision for the future of our built environment. By making higher density, more affordable, and walkable neighborhoods “non-conforming” we effectively state that they do not conform to our vision. That is the greatest loss.

    I propose tabling this ordinance and concentrating on establishing goals and re-writing the zoning code to reflect our vision. We already have good suggestions from our consultant as well as lessons we can learn from our neighboring communities. Let’s charge our new staff planer to lead this process, consider the options available, evaluate the pros and cons and move forward.

  10. David, why are we assuming teardowns are our number one enemy? Houses that are old and crumbling, not well insulated because they were built in a time when energy seemed free and current insulation materials were not yet available, are sometimes better torn down than forever preserved. Having a few houses designated as historic is one thing. Having a whole neighborhood of residential housing designated for restoration only is energetically wasteful, and ignores climate change. Not to mention that it systematically marginalizes already-marginalized residents of Princeton — those that live near the center in smaller lots and smaller houses. Their houses are not more valuable if they have to be refurbished within their current shell. They are more expensive to maintain, and less valuable when sold. Some history is good, but not everything that is old needs to be preserved forever. Otherwise we would be living in wood cabins.

    In my opinion the “missing middle” housing, and the growing unaffordability of Princeton to anyone but the most affluent are much bigger problems than tear-downs. These problems are not caused by teardowns, but are reflected in them. Artificially preventing teardowns is like treating the symptom, but ignoring the disease. And this ordinance goes directly against measures that have been suggested for mitigating the missing middle problem, such as allowing duplexes and accessory dwelling units in existing downtown homes.

  11. Marina – I am truly grateful that you caught the error in the original draft of the ordinance. Please be assured that it was an error and not the intent of staff or Council to remove protections for grandfathered properties. I look forward to seeing whatever you manage to gather for tonight’s meeting regarding the other neighborhoods impacted by this change.

    Yael – thanks for your thoughtful questions. I will just say in this setting that tear-downs are not our number one problem, but they are a problem. I think you know we are working diligently on other solutions to the affordability/sustainability problem. While discouraging tear-downs will not solve our affordability/sustainability issues, encouraging tear-downs does exacerbate them. So I think this ordinance is a step in the right direction while we develop other ways to address them more directly.

    Let me also add that there is no one-size fits all answer to the question of property values; however, I do think that there is one impact that will affect all undersized lots resulting from this ordinance. The assessed value of the land will decrease, which will result in some property tax relief for all owners of these properties. Will this mean that at some point in the future that the resale value of the property will be lower? Perhaps, but that is a theoretical future benefit, while tax relief, targeted at precisely the people who have been hardest hit by the rapidly escalating property values in these neighborhoods, is a tangible immediate benefit that is progressive in its effects. I think if you talk to folks in these neighborhoods, you will find few of them complaining that their property values and taxes are not going up fast enough!

  12. One more thought for Yael – the new ordinance actually does not have any impact on the solutions to the missing middle you mention. Current zoning forbids multiple dwellings, duplexes or accessory dwelling units on undersized lots in the former Borough. Current zoning permits duplex units only on double lots in the former township. While flats are permitted in the former township on undersized lots, they will still be permitted under the new ordinance, though perhaps more squeezed for space.

    My point is that these “missing middle” solutions must be addressed directly, and I commit to fully supporting regulations which will help us encourage them – perhaps an FAR bonus for owners who implement them. But simply letting single family owners build bigger houses accomplishes nothing for the “missing middle”, and in many cases is counterproductive.

  13. @CouncilmanCohen Thank you for participating in this dialogue, and for your candor. A public conversation like this is exactly what is needed here, and on so many other issues in our community. Your participation here on Planet Princeton gives a glimmer of what a substantive back and forth between citizens and council members could be. (Also a HUGE thank you to Marina Rubina for doing the legwork needed to prompt this dialogue).

    What is frustrating to me, and perhaps others, is that notwithstanding your strong statement of commitment to addressing the “missing middle” issue, the Council is taking up this cosmetic housing issue — problematically — before taking up the more critical and fundamental missing middle issue. And at the same time, the Council is continuing to resist settlement on a lawsuit related to needed housing production in our community.

    There are lingering issues of mistrust, lack of transparency, patterns of abruptness in the introduction to Council of policy issues, and mechanisms for public input that are stodgy and incompatible with broad civic engagement (which pattern your participation on Planet Princeton admirably breaks).

    My request would be to table the ordinance not merely until March — as you and Council did last night — but until a substantive missing middle housing solution can also be on the table.

  14. Thank you Nat, for the constructive tone of your post. As mentioned at last night’s meeting, the larger issue of the missing middle is on our agenda for the year. There was some discussion around the fact that the same consultant is engaged to facilitate the Princeton Theological Seminary Redevelopment Plan, and may not have the bandwidth to work on both projects simultaneously. I will follow up and see whether we can proceed with both, or whether Neighborhood Character Phase II must wait until the second half of the year.

    That being said, I want to emphasize that we do not consider the proportional FAR ordinance to be solely a cosmetic issue. Tear-downs drive real estate values up in our more modest neighborhoods, with corresponding tax hikes for those residents least able to afford them. Any policy that discourages tear-downs, at least on undersized lots, should provide some measure of tax relief to the owners of those lots.

  15. I foresee an obvious unintended consequence of this ordinance, if it were to pass. It will provide market-driven incentives for developers to buy out smaller lots at depressed prices, with the purpose of combining them into comforming lots, and continue to build large, single family homes, instead of preserving the relative affordability of the JW neighborhood and other areas zoned for small lots. We need to tackle the root cause of Princeton’s growing socioeconomic segregation: exclusionary zoning. Here is a truly innovative policy that Minneapolis just adopted: https://www.nytimes.com/2018/12/13/us/minneapolis-single-family-zoning.html

  16. Only in New Jersey would a politician not see the irony in talking about how he’s doing you a favor by tanking your property value because he wants to save you from the outrageous property taxes. Gee, thanks pal. Talk about oblivious.

  17. Nice analysis, but blah, blah, blah. No matter what happens, our local taxes will continue to rise. This community has become unaffordable.

  18. This latest version of the FAR-based controls will have the same effect as round one had, almost none. The effect was and will be to raise the cost of development (for planners, land use attorneys, carrying costs and fees) so that the base cost of housing goes up. Variances will continue to be granted to those wealthy enough to afford the inherent costs and spend the time pursuing their projects.

    The new $2,000,000 home on the block will prompt the assessor to revalue the neighborhood so that folks minding their own business will have their mortgage payments eclipsed by their real estate taxes.

    NIMBYism and a suburban mindset have prevented affordability issues in housing from being dealt with creatively. Increased density doesn’t necessarily equal parking and traffic problems. It’s time Princeton had some political leadership around this.

  19. When I look at the data, I see around 3000 existing lots that will be damaged by this proposed ordinance.

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