On Saturday, Nov. 17, Ayer and Shirley voters in a districtwide election held simultaneously in both towns will have their say on the Ayer-Shirley Regional School District high school building project.

In separate elections held at the same time, voters in Ayer and Shirley, respectively, will also be asked to consider debt exclusions to help pay for the project, a proposed $56.6 million renovation and addition.

With two ballots in each town and three questions, total, we think the answers should be yes, yes and yes.

The cost projection looks solid. It's based on professional estimates made during the feasibility study and vetted by the Massachusetts School Building Authority, which has agreed to reimburse the district for 70-percent of covered project costs, or 66 percent total.

The upshot is that if voters approve the project and agree to accept the debt exclusions, the state picks up more of the cost than taxpayers do. A lot more. MSBA is on the hook for $37 million, while Ayer and Shirley share 34 percent of the total cost, or $19 million.

No matter how it's sliced, this is a deal neither town can afford to pass up.

A lot is riding on this project. The district has pinned its systemic improvement hopes to a "flagship" high school aimed at retaining current students and attracting new ones.

Otherwise, officials say, choice-out bleed is likely to continue, diverting millions in per-student revenue from the state to other schools every year.

Dollars that follow those students out of town could instead be used to benefit the home school district.

It's a make or break cycle. So if the new Ayer-Shirley region wants to keep students and state funding for them, shaping up to stay competitive is a must.

An updated, upgraded building with modern science labs and working HVAC system will go a long way toward meeting that goal. The current building has neither.

There are community perks, too. Ask a Realtor. Improving a school system is an investment that pays off.

The cost-side is the tax hike, but it's relatively small, all things considered, about $200 a year in Ayer and $240 a year in Shirley, based on average-valued homes.

If voters say no on the first try, it's sure to come up again. But any future proposal submitted to MSBA would almost certainly go to the bottom of the applicant list and reimbursement might be much lower next time around. Meantime, sunk costs for the feasibility study would be lost as construction costs continue to rise.

No question the renovation/addition is necessary. The 50-year old high school building needs a major overhaul, with enough work on the must-do list to make it a money pit for years. Absent a full-out renovation and with accreditation at stake, the regional school district would have to tackle things piecemeal, rolling repair costs into its budget and billing member towns via the annual assessment, with little or no help from the state.

A golden opportunity would be lost. Ayer and Shirley taxpayers and their kids would get less and pay more, as School Committee Vice Chairman Pat Kelly pointed out at a Building Committee forum in August.

Can you afford that? We don't think so.