Stajka thinks that either one of the windows didn't close properly or the worker forgot to lock it. The next morning, every tool he owned - $6,200 worth - was gone.
"It doesn't seem like a whole lot of money to some people, but it is a whole lot," he said. "My insurance didn't cover it, and it was a struggle to replace the tools so I could get back to work."
Police, contractors and builders associations are constantly after companies to take precautions at their work sites, such as: hiring reputable security companies to patrol the area at night and on weekends; keeping accurate inventories of what is at the site; limiting access to employees; surrounding the site with chain-link fences at least eight feet high, with limited entry and surveillance cameras; and locking up all equipment in secure storage sheds.
"They need to keep equipment out of view and to make someone responsible for making sure it is," Stephens said.
You can only be so careful, though. Sometimes, employees or subcontractors are stealing the stuff.
DeWalt, the tool manufacturer, has tried in the last couple of years to determine the extent of construction-site thefts.
Using responses from 1,700 contractors and builders across the country, DeWalt found that 97 percent of those surveyed were concerned about security, and that tool theft was the No. 1 concern "because of replacement costs, lost time, and decreased personal productivity."
Since DeWalt's customers are largely building professionals, the company's research and development department began looking into a way to keep tools safe on site.
Its solution was Sitelock, a portable wireless alarm system that consists of a base unit and five sensors. The base station is kept indoors, usually in the job-site trailer, and the remote sensors are placed at strategic points - on big toolboxes and material containers on the site, up to 2,000 feet from the base.
If an intruder tries to disturb the protected equipment or remove a sensor, the alarm is activated and a wireless signal is sent to a monitoring service, said spokesman Bill Pugh.
The base retails for $1,000, and the sensors range from $99 to $199. If the builder chooses, he can use DeWalt's monitoring service for $40 a month, or be notified of a problem immediately by e-mail or cell phone for $30 a month.
Bosch, another major supplier of tools for professional use, is working with ToolWatch Corp. of Englewood, Colo., to install radio-frequency detection devices inside tools at the factory, so their whereabouts can be easily tracked by special computer software.
"It's not only theft that concerns builders and contractors, but inventory control," said Bosch spokesman Jason Feldner. "A builder knows he has 19 reciprocating saws on site, but he forgot where they are. That's what the tool-tracking system is for."
There already is a bar-code system for tracking tools, but according to ToolWatch vice president Joe Caston, the new technology is a major improvement. Tools are embedded with identifying tags that link to such information as serial numbers, purchase date, original price, maintenance schedules and authorized users, he said.
Using a handheld scanner, ToolWatch software records the embedded information. Everyone using a tool passes through a portal at the job site that works the same way as the detectors you walk through entering or leaving stores at the mall.
Embedding the information will add 1 to 2 percent to the cost of the tool, Feldner said.
The cost of job-site theft and preventing it is a line item in a builder's annual budget, Granor said. "I guess we have been lucky. We've only had our model homes broken into twice in 25 years, which is, I think, a good record."