City leaders seem to have reached consensus that the Lawrence Police Department needs a new headquarters that provides additional space for department operations.

Some question remains, however, about how much space is needed. Taxpayers also are interested in this equation because it will have an impact on how much money the city has to raise to pay for a new police facility.

The police department now operates out of about 39,000 square feet scattered among six different buildings across town. Architects working on a new police facility say the department needs a little more than twice that much space — 85,000 square feet — just to meet its current needs. However, the architects are recommending the city approve a building that is about 103,000 square feet in anticipation of the department’s future needs.

Even if the department’s current space is completely inadequate, it’s hard to see how more than doubling that space in a more efficient unified location wouldn’t provide at least a little room for future growth. Is the city sure it needs to build a 103,000-square-foot facility now?

To justify the larger building, architects project that Lawrence’s population will grow 1.5 percent per year for the next 20 years. That’s a pretty optimistic figure. In the decade of the 2000s, Lawrence averaged 0.9 percent annual growth; since 2010, the growth rate has been even lower. The architects’ growth projections are far from guaranteed.

Planning for the future is tricky. Even if Lawrence meets the growth projections, other factors may change. For instance, will technology make it less important for the department to have that much physical space 20 years from now? Will other needs arise? The architects aren’t supportive of the idea of building a smaller facility that could be easily expanded later, but commissioners perhaps should insist that option be explored further.

City commissioners seem willing to take a second look at the size of this project. We encourage them to take that step. Lawrence always has a long wish list for tax-supported facilities and services, but in recent years the growth in the tax base needed to fulfill that wish list hasn’t kept up. Taxpayers may see the need for a new police facility but they also would like to see the city take a financially conservative approach to the project.