The new LHS will accommodate 2,395 students. Is that enough?

The predicted future enrollment for the new Lexington High School, which is supposed to open in 2029, is 2,395 students. 

That number was decided by the Massachusetts School Building Authority (MSBA), the state entity the town is working with to finance the new high school. Lexington’s School Building Committee predicts the town will get about $121 million from authority as of its Oct. 6 meeting. 

If Lexington wants to maintain that partnership and get that funding, it has to let the MSBA forecast what LHS’s future enrollment could be. 

But some residents are skeptical of the enrollment number the MSBA drew up. 

Residents have voiced concern that the MSBA’s prediction is too low because of the unknown effects that incoming multifamily housing could have on enrollment. Lexington plans to bring about 1,100 new multifamily units to town as a result of the MBTA Communities Act. Other new housing continues to come online, too. 

This is how that 2,395 figure was born:

The MSBA works with an outside consultant to predict future enrollment. They come up with a baseline number using past enrollment data from the state’s Department of Elementary and Secondary Education, birth data from the Massachusetts Department of Public Health, female population data from the US Census Bureau, and female population projections from the University of Massachusetts’s Donahue Institute. 

According to the MSBA’s website, here’s how that data is used: 

• Birth and female population data are used to calculate fertility rates;
• Fertility rates are applied to actual and projected female populations;
• Birth data and Kindergarten enrollment data is used to calculate an average birth-to-kindergarten ratio;
• The birth-to-kindergarten ratio is applied to actual and projected births to generate Kindergarten enrollments;
• Historic enrollment data is used to calculate average grade-to-grade survival ratios (the proportion of students enrolled in one grade and school year to the number of students enrolled in the next grade and school year) to project the number of students in each grade;
• Grade-to-grade survival ratios are applied to actual and projected student enrollments to generate grade one through 12 enrollment projections; and
• The baseline enrollment is calculated using the ten-year average of projected enrollments for the grades.

Based on that information, the MSBA’s baseline enrollment prediction for LHS was 2,120.

That prediction does not include factors such as incoming housing or immigration waves. As a part of the MSBA’s process, it asks districts to provide information on variables like those to better forecast future enrollment. 

Lexington made the authority aware of how the MBTA Communities Act could impact the town. 

The MSBA normally uses a five-year average cohort survival rate, which essentially assumes that future enrollment patterns will mirror the average of the past five years. But because of the possible impact incoming multifamily housing could have on LHS enrollment, the MSBA used a five-year 75th percentile cohort survival rate for 2024 and 2025, which assumes future enrollment will mirror the highest recent growth patterns rather than the typical ones. Using a higher percentile for the forecast will result in a higher projected enrollment.  

That adjustment added 225 students to the baseline enrollment prediction. 

The town also made the MSBA aware of the high number of students the school enrolls from other districts. Again, the MSBA adjusted accordingly. 

“The MSBA adjusted the grade-to-grade survival ratios for grades 9 through 12 by a total of 3.3 percent throughout a four-year period,” a Jan. 2023 letter from the MSBA to former Town Manager James Malloy states. 

That adjustment added 50 students to the baseline estimate, bringing the total predicted enrollment to 2,395. 

Based on that calculation, Lexington’s design team drew up a school that can accommodate 2,395 students at 85 percent utilization (23 students per classroom). The idea is 85 percent utilization is compact enough that a lot of space isn’t left idle, but comfortable enough that there isn’t overcrowding.

The new high school offers some leeway should more students come to LHS than what the MSBA predicted. The current design of the school includes a 20,000 square foot central office space that could be converted to 11 to 12 general education classrooms. And if that’s not enough space, the school could increase its utilization rate, though that wouldn’t be ideal. 

If the school pushed utilization to 90 percent, classroom sizes could increase to 25 students per classroom. That might be fine in general education classrooms, but bathrooms will feel more crowded, as will the library, auditorium, cafeteria, and other spaces. That increased utilization will also make it more difficult to create schedules and properly transition classes in between periods. 

Ninety percent would still be better than LHS’s reality right now, however. Today, LHS is operating around 97 percent utilization.

The town has also discussed the possibility of building an addition onto the new high school if needed. That would only happen if the converted central office space and increased utilization don’t adequately mitigate overcrowding.

Ultimately, it’s difficult to predict future enrollment, especially with Lexington’s incoming housing as a variable. Yes, the town will get at least 1,100 new multifamily housing units because of the MBTA Communities Act, but new housing could also come in different ways.

Several property owners have successfully applied to freeze an earlier zoning bylaw in place, which gives them the ability to build multifamily housing over the next eight years if they want. One developer applied to divide a Lexington Center property into three and build a cul-de-sac. The town approved his application. Months after he applied, his plan changed — now he plans to build a 50-plus unit multifamily housing complex with commercial space on the property.

“I still think that this high school plan is very appropriate, I think the flexibility is going to be really helpful, but I do think it’s important for everyone to acknowledge that those preliminary subdivision plans have been filed,” Lexington resident Kate Colburn said during one of SBC’s community meetings in March. 

Lexington is working to bring 100 percent affordable housing to town in addition to MBTA Communities Act housing. A 40-unit complex could come to the intersection of Lowell Street and North Street.

That unpredictability is what makes some residents skeptical about the MSBA’s enrollment prediction and subsequently, the size of the new high school. Skeptics think the town should build a larger school in phases. But the MSBA does not usually help finance phased projects.

LPS Superintendent Julie Hackett and others close to the project have said they don’t want to have a high school that accommodates more than 3,000 students. 

“How big is too big for a school, right?” Andrew Baker, principal of LHS, said during a SBC meeting in October 2024. “When does it sort of strip away at the sense of community or create a place that adolescents can’t thrive in because it’s too large to navigate or too large to handle?”