Liza Julian lives on one of Palo Alto's smallest lots, in a 640-square-foot, one-bedroom home that's so small she had to move furniture into the garage when two friends came to visit over Memorial Day weekend.

But when the tax bill arrives, the 58-year-old homeowner pays the exact same amount for Palo Alto Unified School District's annual parcel tax as some of the city's biggest landowners. Stanford University, Hewlett-Packard, Agilent Technologies and Loral Space Systems all own or hold long-term leases on parcels that are far larger than any homeowner's lot.

With a measure on the ballot Tuesday to renew the district's parcel tax and increase it to $493 annually for six years, some residents -- including some of the measure's supporters -- are asking why the district went with the one-size-fits-all parcel tax. Just next door in Mountain View and in towns such as Emeryville and Berkeley, property owners pay a tiered tax that supporters say is fairer across the board -- the bigger the parcel, the bigger the tax.

Palo Alto's decision represents a still-unsettled question about whether tiered taxes are legal under California law. District leaders didn't want to gamble on a tiered tax, similar to Mountain View-Whisman's, that could be contested in court.

``Even if we wanted to, we simply can't,'' said Palo Alto Unified Associate Superintendent Gerry Matranga.

California code says that special taxes must ``apply uniformly to all taxpayers or all real property within the school district.'' However, parcel taxes can offer an exemption to taxpayers who are 65 or older, which Palo Alto does.

That won't help Julian for another seven years.

``I really want to support the schools and pay my share, but I have a tiny house,'' said Julian, an administrative associate at Stanford who lives alone after raising two daughters who attended Palo Alto schools. ``Why am I paying the same as a brand new house many times the size of mine?

``I'm lucky to have a reasonable mortgage, but this is getting to be too much.''

Small homeowners like Julian are exactly who inspired Mountain View-Whisman School District leaders to consider tiering their parcel tax.

``We felt it would be too large of a burden'' on small homeowners, said Rebecca Wright, the district's chief financial officer.

Mountain View's biggest properties -- more than 44,000 square feet -- such as that owned by Lockheed Martin, pay $600 per parcel. The smallest -- 8,000 square feet and below -- pay $75. There are four other tiers in between.

``People here felt it would be fairer this way. If you own a huge lot, that's different from owning 8,000 square feet,'' Wright said.

Hewlett-Packard, for example, pays $600 to the Mountain View-Whisman district for its 15.6-acre parcel in Mountain View -- about $38 per acre. But if Palo Alto passes its parcel tax hike, the company would pay a flat $493 for its 36.4-acre world headquarters -- about $13.50 per acre.

HP and other members of the Silicon Valley Leadership Group oppose a tiered parcel tax, also known as a split-roll tax, because they say it could impede the valley's economic recovery and cost jobs.

Palo Alto's biggest landowner, Stanford University, owns hundreds of parcels, ranging in size from the 580 acres that comprise the campus's athletic facilities and football stadium, to residential lots for faculty housing to the occasional sliver of greenbelt that's less than a third of an acre. Yet each parcel gets the same size bill.

Staunch supporters of Palo Alto Unified's proposal, Measure A, say the bigger problem is Proposition 13, the landmark measure that California voters passed in 1978 to cap property taxes at 1 percent of a property's purchase price with a 2 percent maximum annual increase in a property's assessed value.

``It dwarfs any other inequity in the taxing structure,'' said Palo Alto Unified school board member Mandy Lowell.

Eric Hahn has two children in the district, and his wife, Elaine, is active in the Parent Teacher Student Association.

``It seems like a horrible injustice that the schools are so underfunded given the relative prosperity of Silicon Valley and California in general,'' said Hahn, founding partner of Inventures Group and former chief technical officer for Netscape.

Despite his support for Measure A, Hahn said he would be willing to pay more than Julian because his lot is 50 times bigger than hers.

``Next time around, I think we can think about coming up with something better,'' he said. ``For now, this is a good start.''