Nantucket Has a Housing Plan.

Nantucket unquestionably has a housing problem. More than half of island households are considered cost-burdened or severely cost-burdened, according to data cited in the Town’s new Housing Production Plan, meaning they spend more than 30 percent — and in some cases more than half — of their income on housing. The rate of overcrowding among renter households is estimated at six times the Massachusetts average. The plan even acknowledges the extreme arrangements some workers have resorted to, from multiple families sharing houses to workers occupying the same bed on different shifts.

 

The Town’s newly endorsed 2026 Housing Production Plan attempts to address that crisis over the next five years. It calls for more affordable and year-round housing, more types of housing, streamlined permitting, changes to zoning, better coordination among Town departments and incentives intended to make it easier to create homes for people who actually live and work here. The Select Board and Planning Board endorsed the plan on August 19, sending it next to the state Executive Office of Housing and Livable Communities for approval.

 

There is much in the plan that makes sense. But there’s something else that can become lost in a 92-page housing document: A Housing Production Plan is not the same thing as a comprehensive plan for how much housing Nantucket can physically support. 

 

First, What Is This Plan Actually Supposed to Do?

A Housing Production Plan, or HPP, is a Massachusetts planning mechanism tied primarily to Chapter 40B. Its purpose is to help communities create affordable housing and make measurable progress toward having at least 10 percent of their year-round housing stock qualify for the state Subsidized Housing Inventory, or SHI. A community with an approved plan that meets its annual production requirement can receive “Safe Harbor,” giving local officials greater control over Chapter 40B developments.

 

At the minimum rate of 31 qualifying units per year, Nantucket could theoretically add 155 SHI units over five years, bringing the current inventory from 512 to roughly 667 units, above 10 percent of the present 2020 Census denominator. But 31 units a year is a Chapter 40B production benchmark, it’s not an estimate of how many Nantucket households need housing.

 

That may be the single most important thing for readers to understand about the plan. Nantucket could meet the 31-unit target every year, retain Safe Harbor and eventually cross the 10-percent threshold while still having a severe workforce-housing crisis. Conversely, the Town could make zoning changes capable of generating hundreds or thousands of additional market-rate units without necessarily solving the housing problem the HPP is intended to address.

 

The number of housing units produced and the number of housing problems solved are not necessarily the same.

 

What the Plan Gets Right

The Housing Production Plan is strongest when it recognizes that Nantucket’s housing problem is not simply a shortage of buildings.​It establishes five broad goals: preserve and expand the year-round housing stock; produce housing at different affordability levels; diversify the types of housing available; revise zoning and policy to encourage what it describes as responsible growth; and better coordinate the Town’s financial, regulatory, infrastructure and organizational resources.

 

The plan also identifies some very real obstacles. Permitting can be slow and complicated. Zoning is fragmented and difficult to navigate. Construction costs are extraordinary. Developable land is limited. Conservation, historic preservation, environmental protection and housing sometimes compete for the same finite land and resources. Various Town departments don’t always operate through a common housing framework.

 

Among the recommendations are allowing some housing through a simpler site-plan process rather than requiring special permits; creating incentives for year-round housing; permitting year-round homes on some undersized lots; allowing year-round tiny homes; increasing allowable density in areas considered appropriate for growth; developing pre-approved housing designs; reconsidering portions of the HDC process; and establishing a dedicated housing or permitting coordinator.

 

Some of these deserve debate, but there’s a coherent idea behind them: if Nantucket is going to use scarce development capacity, housing for its year-round community should be easier to create than another unrestricted seasonal bedroom.

 

That principle aligns closely with the conclusion of our Nantucket Carrying Capacity: An Independent Phase 1 Assessment. Our assessment did not argue that Nantucket should stop producing housing. Quite the opposite. It concluded that housing for the existing workforce, overcrowded households and essential employees should continue to be created even while the island is treated as having no assumed additional year-round population headroom. The distinction is between development that stabilizes the population already here and development that creates additional population, vehicles and infrastructure demand. That’s where the two plans can work together.

 

Where the Housing Plan Runs Into the Capacity Problem

The difficulty comes when the HPP moves from creating affordable housing to increasing development potential. The plan recommends increasing housing density in areas considered to have the greatest growth potential. Much of Nantucket’s multifamily zoning and infrastructure is concentrated in and around Mid-Island.

 

But Mid-Island is precisely where the Carrying Capacity Assessment found Nantucket has the least transportation headroom. Our assessment concluded that Nantucket does not have one single capacity limit. Roads, water, wastewater, schools, emergency services, waste disposal and environmental systems each have their own limits, and the island’s practical capacity is determined by whichever critical system reaches its limit first. Based on available evidence, transportation and Mid-Island circulation are already the binding constraints.

 

The assessment therefore recommended designating Mid-Island a Transportation Capacity Red Zone, with no major development producing a net increase in morning or afternoon peak-hour vehicle trips. It specifically said that housing should receive preferential treatment there only when year-round occupancy is enforceable and the project includes vehicle limitations, transit access and reduced parking.

 

This doesn’t mean the Housing Production Plan is wrong to put housing near existing sewer, water, stores, schools and transit. In many ways, that remains the logical place for it. But it does mean density cannot be evaluated independently of transportation capacity.

 

Adding 50 year-round apartments near Old South Road may be a far better use of Nantucket’s limited capacity than adding 50 unrestricted seasonal homes elsewhere. But those apartments still generate traffic, wastewater, school enrollment and emergency-service demand. The question is not simply whether housing is good, it’s how much demand it creates, when it creates it, and what demand is reduced elsewhere to make room for it.

 

The Missing Half of the Equation

This is also where criticism raised during the adoption process deserves some consideration. Massachusetts regulations do not merely require an HPP to describe housing needs. They specifically require the housing-needs assessment to examine the capacity of municipal infrastructure to accommodate the existing population and anticipated future growth, along with plans for necessary infrastructure expansion.

 

The Nantucket HPP acknowledges infrastructure as a constraint. What it does not appear to provide is a quantified island-wide capacity envelope showing exactly how much reliable water, sewer, transportation and other capacity remains before additional growth is encouraged.

 

That concern was raised before adoption, and Select Board member Matt Fee acknowledged during the August 19 meeting that a deeper understanding of infrastructure capacity is important and requires additional follow-through. At the same meeting, vice chair Brooke Mohr emphasized that the HPP has a narrower purpose: complying with Chapter 40B and retaining local control, rather than regulating every form of development on Nantucket.

 

Both observations can be true. The HPP should not be expected to become Nantucket’s entire growth-management plan. But housing production cannot be planned in isolation from infrastructure capacity either.

 

Our own Phase 1 assessment identified exactly this problem. Wannacomet’s annual reports provide water-production figures, but not a single publicly accessible calculation of drought-adjusted firm capacity under peak summer conditions with a major well unavailable, fire-flow reserves preserved and already-approved development included.

 

The sewer system presents a similar issue. The Surfside treatment facility has a design maximum-day capacity of 3.5 million gallons and a permitted maximum discharge of four million gallons, but permitted capacity is not the same as reliable system capacity.  Before Nantucket deliberately increases development potential, those numbers should be known.

 

About That 17,432-Unit Number

One number in the HPP has generated particular attention. The plan’s buildout analysis reportedly identifies the theoretical potential for as many as 17,432 additional dwelling units on existing lots under current zoning. Town planning officials emphasized during the August 19 discussion that this is a theoretical buildout calculation prepared through the Weston & Sampson analysis, not a prediction that another 17,432 homes will actually be built.

 

The Housing Production Plan is not proposing to build 17,432 houses. But the number demonstrates just how different zoning capacity can be from real-world carrying capacity.

 

Our Capacity Assessment encountered the same issue using the Town’s 2025 Master Plan data. That analysis found theoretical zoning potential for approximately 9,615 additional dwellings on existing lots outside the Sewer Master Plan study area alone, with existing lots utilizing only about 41 percent of their permitted dwelling-unit capacity. The scope and methodology of that calculation are different from the HPP’s broader 17,432-unit buildout figure, so the two should not be treated as competing estimates. What they demonstrate together is the same fundamental problem: Nantucket can legally authorize far more development than its infrastructure may be capable of absorbing.

 

So, Does the Plan Realistically Address Nantucket's Housing Need?

Partly. As a Chapter 40B Housing Production Plan, it’s a serious and potentially useful roadmap. Nantucket has made substantial progress toward the 10-percent SHI threshold, and producing at least 31 qualifying units annually is a realistic and important goal.

 

As a broader solution to Nantucket’s housing crisis, however, that number is nowhere close to being a measurement of actual need. The plan itself says more than half of island households face housing cost burdens and that overcrowding among renters is dramatically above the state average. Producing 31 subsidized units annually may satisfy the state production benchmark, but it cannot reasonably be interpreted as solving a housing market operating at that scale of dysfunction.

 

At the same time, simply producing hundreds more units each year would create another problem if those units add population, vehicles and infrastructure demand to systems already under strain. That’s the Nantucket dilemma. The island simultaneously has a housing shortage and a capacity shortage, and Nantucket has to become far more selective about what kind of growth receives access to the capacity that remains.

 

Our Capacity Assessment proposed a temporary five-year allocation of no more than 1,000 additional bedroom equivalents — an average of 200 per year — and only when the relevant capacity systems can support them. Permanently affordable and year-round-restricted housing would receive first priority, followed by housing for essential workers, replacement of unsafe or severely overcrowded housing, senior and accessible housing and other enforceably year-round homes.

 

How the Two Plans Could Be Reconciled

Nantucket does not need to choose between housing and carrying capacity. It needs to make housing policy part of carrying-capacity policy.

 

A workable approach would be:

1. Give permanently affordable and year-round-restricted housing first claim on available development capacity. Preservation and conversion of existing homes should be particularly valuable because they can stabilize housing without always creating equivalent new population and infrastructure demand.

2. Tie new zoning and density incentives to enforceable public benefit. If additional density is granted in the name of workforce housing, the resulting units should remain year-round housing after the property is sold. Otherwise, the island risks increasing development rights only to have some of the resulting units migrate into the seasonal or investment market.

3. Require transportation neutrality in Mid-Island. More housing may still belong there, but major projects should demonstrate how additional peak-hour trips will be avoided or offset through parking limits, transit, walking and biking access, employer transportation programs or retirement of existing trips.

4. Publish real infrastructure capacity before expanding development capacity. Water, sewer, roads, schools, public safety and environmental systems should each have measurable operating limits, reserves and committed-but-unbuilt demand.

5. Measure bedrooms and demand, not simply housing units. A small one-bedroom apartment occupied year-round does not have the same capacity impact as a six-bedroom seasonal property with multiple vehicles, landscaping crews, deliveries, irrigation and short-term occupants.

6. Issue one annual Housing and Capacity statement. Nantucket should report not only how many affordable units it produced, but also how many total bedrooms were added, how many were permanently restricted to year-round use, how many entered seasonal or short-term-rental use, how many vehicles were added, and what happened to traffic, water, wastewater, school enrollment and emergency-service demand.

 

That last recommendation closely follows the annual capacity-budget framework proposed in our Phase 1 assessment, which would place housing production alongside population, vehicles, water, sewer, schools, public safety, waste and approved-but-unbuilt development in one annual accounting.

 

In Closing

Nantucket’s Housing Production Plan correctly recognizes that the island cannot maintain a functioning year-round community without housing the people who teach its children, staff its hospital, patrol its streets, operate its businesses and keep Nantucket running. But the island cannot solve that shortage simply by continually expanding infrastructure and development to accommodate each new round of growth. The Carrying Capacity Assessment reached a complementary conclusion: Nantucket has already exceeded practical capacity in important areas, particularly transportation and Mid-Island circulation, and the answer is not to stop growth altogether but to move from unbudgeted growth to allocated growth.

 

The question is no longer simply whether Nantucket should build more housing, but what kind of housing deserves priority when the island has limited capacity left to spend. Housing for the people who already sustain the year-round community should be near the top of that list. The Housing Production Plan tells us what Nantucket needs; the Carrying Capacity Assessment asks what Nantucket can sustain. Responsible planning now requires the Town to answer both questions at the same time