A. Contractors with field offices. City of Reading contractors or subcontractors engaged in the performance of building and construction contracts at a point outside the territorial limits of the City of Reading may exclude from the measure of the tax the receipts derived therefrom, provided that a field office was maintained on the premises of the project during the performance of the contract to such an extent as to constitute doing local business at the situs of the job.
B. Alterations and repairs. The provisions of this section apply only to contractors engaged either in the erection of new buildings or in the complete alteration and remodeling of old buildings. They do not apply to contractors who engage in alteration or repair jobs of a limited scope, such as a roofer repairing a damaged roof of a building situated outside the City of Reading, or a painter renovating apartments in an apartment house located outside the City of Reading.
C. Engineers and technicians. The exemption provisions of this section do not apply to engineers and other technicians rendering personal services outside the City of Reading.
D. Qualifications for exemptions. To qualify hereunder, the contractor must show that he established a place of business at the situs of the job by setting up a field office thereat with machinery and equipment for the use in fulfillment of the contract, and performed such other acts as to constitute doing local business at the situs of the job.