Work is starting on a 286,072-square-foot spec building in Spreckels Park on a parcel that backs up to the Highway 99 northbound transition ramp to the westbound 120 Bypass.The shell for the spec building being pursued by Scannell Development is valued at $16.7 million based on a permit the City of Manteca issued in September.Currently the city is reviewing a foundation permit valued at $2.7 million for a 585,000-square-foot spec building in the Pacific Business Park where Amazon is opening a Prime delivery center just west of the Manteca Unified School District office complex on Louise Avenue. When it is finished, it will edge out the Ford Motor Small Parts Distribution Center on Spreckels Avenue by 35,000 square feet as the largest commercial structure in Manteca.The Scannell building when coupled with six other projects now underway brings the value of building permits issued for commercial endeavors so far in 2017 to $48.4 million. Work is underway on the 404,657-square-foot distribution center now under construction on Airport Way south of Roth Road for the relocation of 5.11 Tactical distribution operations from Modesto and Lathrop.The two new spec buildings — as well as a proposed 1.2 million square-foot structure CenterPoint is moving forward with that is known as the Laurie Project near the 5.11 Tactical site — is expected to put Manteca in the hunt to land more jobs.In the first nine months of the year the city has issued 1,018 permits for construction work valued at $168.1 million.