Landlords love it when the value of their properties goes up — at least until the tax bill comes.

The value of Nashville's commercial properties has increased in the latest appraisal by the Davidson County Assessor of Property office, which appraises properties once every four years. Meanwhile, residential properties have stayed relatively flat since 2009.

"Commercial property values are still going up pretty rapidly from what we are seeing on some of the sales prices," said Assessor George Rooker. "As far as the economy, it's a real positive."

Investors and developers pay close attention to property appraisals. Increases that are significantly higher than expected could have a chilling effect on development and cool investor interest in acquisitions, say real estate experts.

Apartments experienced the biggest jump, rising 26.5 percent on average compared to 2009. Here are how assessed values for other property types changed:

• Hotels increased 16.7 percent

• Retail properties climbed 13.7 percent

• Office properties rose 13.4 percent

• Warehouses were up 7.3 percent

• Single-family homes and condos dipped by about 0.6 percent

Not happy about the increase? The final deadline to file for a formal appeal of your property reappraisal is this Friday.

"Anybody who is concerned should call our office and schedule an appeal," Rooker said. "We would love to sit down and talk to (property owners) and make sure that they are not overvalued or undervalued."