New homes and Brookline's budget

Enrollment in Brookline's public schools is expected to keep falling. If the Town keeps its school staff and classrooms at today's levels, as the School Department plans, new homes are among the cheapest ways to add revenue between now and 2040.

Summary

Brookline's schools have room, and will have more. There are 6,889 students this fall, down from 7,855 in 2019, and the number is expected to fall to about 6,000 by 2040, mainly because fewer children are being born in town. This year's kindergarten through grade 8 classes already have about 945 empty seats under the School Committee's own class-size limits.
The School Department plans to keep today's teachers and classes, even as enrollment falls. So those empty seats will stay open unless something fills them.
Police and fire staffing has not grown with housing. Brookline added about 1,640 homes over the last fifteen years, and the number of police officers and firefighters did not go up.
That changes what a new home costs the Town. The usual estimate says a typical new apartment roughly breaks even, because it assumes every new student needs new teachers. If new students fill seats that are already empty, the same home brings the Town about $2,900 a year more than it costs.
There is room for a lot of homes, but not unlimited. On top of the roughly 166 a year Brookline already builds, the empty classroom seats could take the children from about 1,300 more homes by 2030 and about 3,600 more by 2040.
The Town has to choose. It can keep those classes and fill them, or combine classes as enrollment falls and save money. It cannot do both. If it keeps them, as the School Department plans, new homes are among the cheapest ways to add revenue between now and 2040.
This depends on enrollment falling. The School Department's own forecast expects enrollment to rise again from 2029, to about 7,400 by 2034. That would take more children moving into Brookline, for every child born here, than in any year of the last two decades, including the boom of the 2010s, at a time when fewer children are being born in town. If it does happen, the empty seats fill on their own and the advantage goes away.

The usual math

The usual way to estimate what a new home costs the Town compares the property tax it pays with the cost of the Town services its residents use and of educating its children. For a typical new home in Brookline, mostly rental and assessed at about $430,000, it comes out roughly even:

Revenue to the Town: about $4,400 a year in property tax.
Expenses to the Town: about $4,900 a year in total:
Town services, about $866 a year (police, fire, public works and the rest, with staff benefits);
schools, about $4,000 a year: on average 0.244 school-age children per home, each costing about $16,443 a year.
Net: about $500 a year short when the home opens.

This site's main forecast, the base case, also uses this method for new homes, with one difference: it applies it only to homes built faster than Brookline's recent pace of about 166 a year, because the children from homes at that pace are already in the enrollment forecast it uses. The $16,443 is what the base case charges for each added student in FY2027: about $12,100 for added teachers, aides and other staff at today's ratio (about one position for every 8.5 students in the parts of the budget that move with enrollment), about $2,500 for supplies, transport and other costs that move with each student, and about $1,900 for the added staff's health insurance and payroll costs. It assumes that every added student brings added staff. That fits a growing school system, and Brookline's enrollment is falling.

Schools: fewer students than the classrooms can hold

Brookline's public schools peaked at 7,855 students in FY2019. This fall (2026) there are 6,889. Births to Brookline residents have fallen from about 690 a year in 2008–13 to 422 in 2023. NESDEC's enrollment forecast, which the base case uses, has enrollment falling to about 6,000 by FY2040.

Enrollment is falling below what the schools are staffed for

Public school students, PK–12. Actual through FY2026, then NESDEC’s projection (the base case) and, dashed, the School Department’s forecast through FY2034. The shaded area is the empty seats if classes stay at the FY2027 level, as the base case assumes.

Why the base case does not use the School Department's forecast. The School Department plans with a 2023 forecast by Cropper-McKibben, the orange dashed line. It has been closer than NESDEC for the last two years, and it has enrollment rising from FY2029 to about 7,400 by FY2034. In the report's own words, the rise comes from new apartments, older owners selling homes to families, and young households continuing to move in; it assumes about 1,500 new homes from 2020 to 2034, fewer than Brookline's recent pace. The base case uses NESDEC because its decline follows births. The children who will start kindergarten through fall 2028 are already born, and births to Brookline residents fell from about 590 a year in 2015–19 to 422 in 2023. Reaching about 7,400 would take more families moving in, for every child born here, than at any time in the last twenty years, and NESDEC's path already assumes somewhat more than the 2010s boom. If the School Department's forecast is right, enrollment passes the FY2027 level by FY2029 even without extra homes, and the usual math applies.

The schools are not being staffed down to match. The base case holds school staffing at the FY2027 level, as the School Department's current plan does, and this school year's classes already have room. The School Department's FY2027 projections, shared with the Advisory Committee this spring, put kindergarten through grade 8 at 4,513 students in 233 classes. Against the School Committee's own class-size guidelines (22 in kindergarten through grade 2, 25 in grades 3–8, lower at Pierce and Driscoll), those classes have about 945 empty seats, and no grade at any school is over its guideline:

School	Students, FY2027	Seats at guideline	Empty seats	Full
Baker	670	820	151	82%
Driscoll	540	678	137	80%
Hayes	381	457	77	83%
Lawrence	616	742	126	83%
Lincoln	465	598	133	78%
Pierce	544	632	88	86%
Ruffin Ridley	850	955	105	89%
Runkle	448	576	128	78%
K–8 total	4,513	5,458	945	83%

Brookline High School (2025–26; building size, not class sizes)	2,147	about 2,700	about 550	80%

The high school was expanded in 2022; its seat figure is the enrollment its architects designed the expanded building for.

Holding staff flat as enrollment falls also changes the ratio of students to staff. In FY2019 there were 5.97 students for every school staff member; in FY2027 there are 5.67; with staff held at the FY2027 level and enrollment at NESDEC's projection, there would be 4.93 by FY2040, fewer students per staff member than in any year since the series began in FY2008. Across all of Brookline's roughly 29,000 homes, public school students per home fall from about 0.24 today to about 0.19 by FY2040. The falling ratio is another measure of the same empty seats.

The rest of this page leaves out the 945 seats already open and counts only the seats the decline adds: how many students could arrive before enrollment is back to the FY2027 level. That number grows each year, from about 300 students in FY2030 to about 900 in FY2040.

Town services: police and fire have not grown with homes

About 1,640 homes were added in Brookline from FY2011 to FY2025, and the Town's public safety staffing fell by five positions over the same years. Fire staffing is set by stations and companies, each staffed around the clock, so it changes in steps rather than with each home; Brookline has budgeted 161 firefighters since FY2010, and it fields more police and firefighters for its size than most comparable towns.

RKG Associates, the Town's consultant, assumes a new home costs the Town $1,371 a year in new expenses for Town services, not counting schools. It gets there by dividing the parts of each department budget it judges to grow with households evenly across existing homes, so a new home is assumed to need the same share of police and fire as an average one; 88% of its department figure is police and fire. That is an average cost, and Brookline's own record does not show police and fire growing that way.

The base case instead uses $660 a year in FY2025 dollars ($866 with benefits in FY2027), measured from what actually happened: across 350 Massachusetts towns from FY2011 to FY2021, 10% more homes went with about 2.2% more department spending. About $230 of the $660 is public safety. The base case holds Town staffing at the FY2027 level, so the $660 does not pay for new positions. It covers the other ways more households add to department spending, which in the towns studied rose across departments, not only in public safety. Given Brookline's own record, it is probably on the cautious side. Under either figure, Town services cost far less per home than schools.

Net financial impact of a new home when its children fill empty seats

At Brookline's average of 0.244 school-age children per home, every type of new home pays for itself when its children fill empty seats. Under the usual estimate, all but the lowest-value rental apartments do too.

If a new home's children join classes that are already running, the added cost is the supplies, transport and other costs that move with each student, about $2,477 a student in FY2027, not a share of a new teacher. Here is what each type of home brings the Town each year after its costs, both ways:

What a new home brings the Town each year, after its costs

Property tax minus Town services and schools, per home per year, at Brookline’s average of 0.244 school-age children per home. Two bars per home: the usual estimate, and children filling empty seats.

Tax at FY2025 values and the FY2026 rate; costs in FY2027. "Average new-construction project" counts each recent project once, whatever its size, so it leans toward small projects such as single-family homes and two-families; counted home by home, the average new home is the $430,000 one.

Filling empty seats, even the lowest-value apartments would need about 1.4 school-age children per home before they stopped paying for themselves. Brookline's recent developments range from about 0.03 to 0.56.

How many homes, and what they add

The base case already includes about 2,500 new homes by FY2040: about 166 a year, plus the approved Chestnut Hill plan. The enrollment forecast already counts their children. On top of those, the empty classroom seats that open as enrollment falls could hold the children from about:

1,600family-sized rentals, at 0.56 school-age children each

3,600or average new homes, at 0.244 children each

8,100or apartments like Brookline's recent ones, at 0.11 children each (the Town's figure)

Those are FY2040 figures. The room grows as enrollment falls, so by FY2030 it is about a third as large: about 560 family-sized rentals, 1,300 average homes or 2,900 apartments.

Run through the base case forecast, the difference shows up in the budget. Each bar is what the extra homes add to the FY2040 budget after their costs:

What extra homes add to the 2040 budget, after their costs

Extra homes beyond the base case, built by FY2040. Each bar is the added property tax and other revenue minus the added Town and school costs, in FY2040, $ millions a year.

About 2,900 extra homes, which the empty seats can hold, add $5.2 million a year under the usual estimate and $23.2 million if their children fill empty seats. At about 7,000 extra homes, more than the empty seats hold, later students do need new staff, and the difference stops growing: $12.5 million against $34.6 million.

Keep the classes, or combine them

Empty seats are not free. The Town is paying for classes with room in them, and it could instead combine classes as enrollment falls and save money: in the base case forecast, letting school staff follow enrollment down would add about $22 million a year by FY2040. The same seats can be cut or filled, not both, so decisions about housing and about school staffing are linked. If Brookline keeps its classes, as the School Department plans, new homes are among the cheapest ways to add revenue between now and 2040. If it combines classes to match falling enrollment, the usual math applies again, and a typical new home roughly breaks even.

Limits

Seats are in specific schools and grades. Ruffin Ridley and Pierce are fuller than the rest, and Pierce's guidelines reflect space limits at its Fisher Hill site. A large building's children all arrive in one school's district.
Children per home varies. The 0.244 average hides a range of about 0.03 to 0.56 in recent Brookline buildings; tenure and bedroom count decide where a project lands.
Special education costs do not follow seats. About 18% of Brookline students have an IEP, and some services and out-of-district placements cost far more than a seat.
The enrollment forecast could be wrong. If enrollment follows the School Department's forecast instead of NESDEC's, there are no empty seats to fill from FY2029.
Step costs. A new fire company, a new school building or a bus route arrives all at once. The base case charges average costs and does not model those steps.

Other kinds of new growth

Most of Brookline's new growth is not new homes. Renovation of existing homes is almost half of it, and commercial property and business equipment make up most of the rest. Those add tax with little or no added cost. Each tenth of a percentage point of new growth, faster or slower, is worth about $8 million a year by FY2040, and the reference document sets out how Brookline compares with the rest of the state.

Try it yourself

The Forecast Explorer has the controls used here: Property tax new growth and Where added growth comes from set the amount and the source, and Students from added homes chooses between new staff and empty seats. The reference document has the full working for the breakeven test and births and enrollment (Part 3c), and for the growth rate (2c and 4c).