Property value notices were mailed out to homeowners in late March by the Harris County Appraisal District, which expects to see a 15 percent increase in residential property values across the county.

"Many property owners will likely be looking at value increases this year, while taxing jurisdictions should expect to see increases in their taxable value base," Harris County Chief Appraiser Sands Stiefer said. "Even in the face of falling oil prices and some job losses, the Harris County economy in general is doing very well. What property owners should understand is that we are looking at the property value for Jan. 1 and basing our reappraisal on the prices property sold for in 2014."

Some of the growth in residential property values can be attributed to new construction, but the majority came from increasing values of existing homes. Almost 90 percent of homes in the county increased in value since last year, according to HCAD.

HCAD is responsible for determining the value of roughly 1.7 million parcels of land in the county each year. Because of the sheer volume of properties, HCAD cannot visit each home individually and instead calculates the values through a mass appraisal process by using data and numbers on home sales in the area, HCAD spokesman Jack Barnett said.

"We have the neighborhoods broken down by market area so that we're comparing similar types of homes," he said. "We don't want to compare a smaller two-bedroom home to a big River Oaks mansion."

If property or homeowners do not agree with the appraisal value, they do have the ability to protest. In 2014, more than 335,000 protests were filed in Harris County, according to HCAD. Property owners can file a protest in a variety of ways, including online through iSettle, by meeting with a representative from the appraisal district or by attending an Appraisal Review Board hearing.

"We always tell people they know their neighborhood and property better than anyone else," Barnett said. "If you think your property isn't the same as your neighbors, file that protest and let us know."

For more details on appraisal protests, visit www.hcad.org.