The size of your property tax bill can be sealed long before the school district budget process starts.

It comes down to property tax base, and whether or not it has increased so that the district can keep pace with rising expenses.

New construction and renovations and new businesses lead to more money for districts.

"You get natural (revenue) growth without doing anything," said York City School District business manager Richard Snodgrass.

In York County, though, there has been little growth in the overall property tax base in recent years, especially compared to how quickly expenses are rising.

And that's made it nearly impossible for some districts to avoid a tax increase, according to a York Dispatch analysis and interviews with school business managers.

How it works: First, some school district economics 101.

A district preparing its annual budget must first calculate how much revenue it can get from taxing all the property within the district.

If expenses are higher than the tax-generated revenue, the district is going to consider increasing taxes to keep up. If property values grow quickly enough, though, the district likely can earn enough revenue without having to hike taxes.

Since 2006-07, when reassessments kicked in and the state put in a property tax cap, county districts have experienced about a 7 percent overall growth in property value, or about 1 percent per year.

Expenses in that time? They're up about 25 percent overall, on average.

"That's the challenge we've had," said Spring Grove Area School District business manager George Ionnaidis. "You're already in the hole. You're behind the eight ball right from

the start."

Ionnaidis recalled how he once told his school board about the district's property tax base.

"I told them I've got good news and bad news. The good news is we went up half a percent. The bad news is we only went up half a percent," Ionnaidis said.

Expenses outpace growth: Rising overall property value is the best way for districts to generate revenue.

"Say you have 2-3 percent growth," Ionnaidis said. "That's an automatic 2-3 percent increase in income without raising taxes."

The stagnation in recent years, business managers said, has led to school districts' taking less-desirable options to balance budgets, like program cuts, furloughs, adding new fees for students and draining the surplus.

"Finally, if there's no place in the budget, then you start looking at raising taxes," said Red Lion Area School District business manager Terry Robinson.

A prime example: York City School District has had negligible property value growth since 2006-07, when the overall base was at about $1 billion.

Meanwhile, expenses have grown by 47 percent, from $73.4 million in 2006-07 to $108 million in 2012-13, despite massive furloughs and program cuts.

That's helped fuel, in part, a 24 percent spike in property taxes during that time. And high taxes, Snodgrass said, have scared potential homeowners out of the city, which decreases the potential tax base, which causes the need to raise taxes, and so the cycle goes.

"I understand when people get frustrated," Snodgrass said. Many aspects of the rising expenses come from state mandates, and so increased costs are unavoidable. "We have to try to work our way through it."

The economy: Tax appeals also cause major revenue growth issues.

When the housing bubble burst a few years ago, homeowners were faced with a property tax bill they suddenly couldn't swing on a home that suddenly wasn't worth nearly as much as when they bought it.

So appeals have been coming by the dozens to the county assessment office by people trying to get a more accurate, present-day value to help drive their taxes down.

It's a direct benefit for homeowners trying to make ends meet, but it's a killer for district revenue, which can lead to districts needing to raise taxes to make up the difference, which can lead to more homeowners needing to appeal to drive taxes down -- yet another troubling cycle.

According to the county assessment office, there were more than 1,700 property assessment appeals in 2012. An overwhelming majority went in favor of the homeowner. In total, about $88.9 million in property value reductions were made, a direct revenue loss for districts.

"That's hurt school districts considerably," Ionnaidis said.

Steve Snell, executive officer of The Realtors Association of York and Adams Counties, said he thinks property value growth will gradually turn around.

In the meantime, property tax reform is needed to help avoid the consequences of districts relying so heavily on property values.

"This is one example why reliance on property taxes to fund the school system is a poor and unfair method," Snell said.

The right growth: The problem isn't as simple as hoping for fewer appeals and a rise in property value, either.

Red Lion's Robinson said even when there is property growth, it needs to be the right kind of growth. New housing units filled with families can actually cost the district more than they're worth. A home that's assessed $3,000 in taxes might have two children who cost $20,000 a year to educate.

What districts need is lots of commercial growth, he said, since that's tax revenue without the expense of new students. Central York is a prime beneficiary of this, with the largest tax base in the county, thanks in part to Harley-Davidson and other commercial property.

Central, which collects $2.88 million for every mill, hasn't raised taxes in three years. Northeastern School District, with a high school just a couple of miles away from Central, gets only $1.38 million for each mill because it doesn't have nearly as much commercial property.

The disparity shows up on the tax bills: Central's mill rate is 17.76, while Northeastern's is 24.26,

For a $150,000 homeowner, that's the difference in paying $2,664 in property taxes versus $3,639.

"Central is very fortunate. Not every district has that" tax base, said Central York board president Michael Wagner. The property tax system creates "inequities" in education, he said.

Dallastown Area School District has had property values grow about 5 percent in the past seven years, one of the lowest rates in the county. Expenses have grown 28 percent during that time, above the county average. And yet property tax rates have gone up only 18 percent, including no tax hikes the past three years.

The difference is Dallastown, just like Central, gets so much more for its tax-levying buck. For every mill Dallastown Area School Board levies, Dallastown pulls in $2.78 million.

York City is on the other end of the spectrum. The district gets only $1 million for every mill. Dover and Northeastern are in a similar situation. The county average of $1.7 million per mill in 2012-13 is only about $100,000 higher than it was in 2006-07.

"We hurt but we haven't hurt as bad as the other districts have," Dallastown business manager Donna Devlin said.

Dallastown, for example, got a boost in the past year from $500,000 in additional tax revenue from WellSpan property expansion. And other business growth is helping the tax base tread water against sluggish residential growth.

But even so, Dallastown has had to find ways to trim its budget, such as wage freezes and energy-savings plans, in order to avoid tax increases.

"It's a constant juggling act," Devlin said.

-- Reach Andrew Shaw at ashaw@yorkdispatch.com