Appeal from the Circuit Court of Cook County. Honorable Alexander P. White, Judge Presiding.
 The opinion of the court was delivered by: Presiding Justice Wolfson
 In an attempt to stimulate economic growth and neighborhood revitalization, the Chicago City Council enacted a transfer tax exemption for real property "used primarily for commercial or industrial purposes."
 The plaintiff West Belmont, L.L.C. ("West Belmont") purchased property at 1711-17 West Belmont Avenue in order to develop and build residential townhomes. West Belmont was denied a real property transfer tax exemption by the City of Chicago because the property was not "used primarily for commercial or industrial purposes" under the Chicago Municipal Code. The circuit court affirmed the administrative hearing officer's decision upholding assessment of tax, penalties, and interest against West Belmont. We affirm.
 On January 26, 1998, West Belmont bought the property commonly known as 1711-1717 West Belmont Avenue in Chicago (the "property") from American National Bank and Trust Company of Chicago. The property previously had been occupied by Roosevelt Chair & Supply Company ("Roosevelt"), a furniture retailer, wholesaler, and rental company. Following the purchase, West Belmont demolished the furniture store and began selling and constructing residential townhomes on the land.
 West Belmont filed a declaration claiming the transfer was exempt under section 3-33-060(L) of the Chicago Municipal Code because it purchased real property used primarily for commercial purposes located in an enterprise zone. Chicago Municipal Code §3-33-060(L) (1999). After an investigation, the Department of Revenue ("Department") disallowed the exemption because the property was being developed to build townhomes--not a commercial or industrial purpose.
 Chapter 3-33 of the Municipal Code imposes the Chicago Real Property Transfer Tax on "the privilege of transferring title to, or beneficial interest in, real property located in the city." Chicago Municipal Code §3-33-030 (1999). The tax is imposed on the transferee at the rate of $3.75 per $500.00 of the transfer price, or fraction thereof, of the real property or the beneficial interest in real property. Chicago Municipal Code §3-33-030 (1999). Section 3-33-060 lists transfers that are exempt from the tax. The exemption at issue in this case exempts:
"L. Transfers of title to, or beneficial interest in, real
property used primarily for commercial or industrial purposes
located in an enterprise zone, as defined in Chapter 16-12 of
this Code." Chicago Municipal Code §3-33-060(L) (1999).
 An enterprise zone is a depressed area of the City which has been designated a "proposed enterprise zone" by the City Council and approved and certified by the proper state or federal authorities as an enterprise zone. Chicago Municipal Code §16-12-020 (1999). Both parties agree the property is located in an enterprise zone.
 The Department sent West Belmont a Notice of Tax Determination and Assessment requesting unpaid Real Property Transfer Tax and interest in the amount of $11,264.06. The Department sent a second notice for $14,934.37, including penalties for negligent and late payments.
 On November 19, 1998, West Belmont filed a protest and petition for hearing with the City. On December 23, 1999, West Belmont filed an amended protest. West Belmont contended the transfer was exempt because: (1) up to and including the transfer date, Roosevelt had used the property for commercial purposes; (2) after the transfer, West Belmont used the property for the commercial purpose of selling residential townhomes; and (3) West Belmont's activities fit the definition of industrial property because it used raw construction materials to make physical goods that were sold to the public.
 At the hearing, the Department relied on its Chicago Real Property Transfer Tax Ruling No. 2, promulgated December 23, 1998, and effective January 4, 1999, limiting the exemption to property used primarily for commercial or industrial use after the transfer.
 On May 31, 2001, the administrative hearing officer (AHO) affirmed the assessment of tax against West Belmont. In her decision and order, the AHO found the property was not "used primarily for commercial or industrial purposes" up to and at the time of transfer as required by the exemption. Based on the evidence, the AHO concluded the property either was vacant up to and at the time of transfer, or the property was the site of sales activity related to a planned residential real estate development up to and at the time of transfer. In either case, West Belmont was not entitled to the exemption because real estate sales activity did not constitute a "commercial or industrial purpose" under the plain and ordinary meaning of those terms.
 The AHO did not discuss the Chicago Real Property Transfer Tax Ruling No. 2 in her decision. She noted: "whether the enterprise-zone exemption also imposes a requirement of commercial or industrial use after transfer, it imposes such a requirement at the time of transfer. Consequently, because, as will be seen, West Belmont fails the threshold requirement, its claim to the enterprise-zone exemption cannot prevail."
 On July 29, 2001, West Belmont filed a complaint for administrative review in the circuit court. On November 20, 2002, the court affirmed the AHO's decision, finding: (1)the AHO did not err by relying on the sales contract as evidence; (2) the AHO followed the appropriate rules of statutory construction by limiting the exemption to property used for commercial purposes up to and at the time of transfer; (3) a conclusion that the property was not "used primarily for commercial purposes" was not against the manifest weight of the evidence; (4) West Belmont's use of the property did not meet the plain definition of commercial purpose.
 West Belmont filed a motion for reconsideration or clarification. The court denied the motion, holding it was not within the scope of the court's review to determine the AHO's meaning of "time of transfer."
 I. Standard of Review
 In reviewing a final decision under the Administrative Review Law (735 ILCS 5/3-101 et seq. (West 2002)), we review the administrative decision and not the circuit court's judgment. Metropolitan Water Reclamation District of Greater Chicago v. Department of Revenue, 313 Ill. App. 3d 469, 474, 729 N.E.2d 924 (2000). Our review extends to all questions of fact and law presented in the record. 735 ILCS 5/3-110 (West 2002). An administrative agency's findings and conclusions on questions of fact are deemed to be prima facie true and correct. 735 ILCS 5/3-110 (West 2002).
 Here, the issue concerns the Department's interpretation of a municipal ordinance, a question of law we review de novo. Branson v. Department of Revenue, 168 Ill. 2d 247, 254, 659 N.E.2d 961 (1995). An agency's construction of a statute it is charged with administering is considered relevant, but not binding on the court. Branson, 168 Ill. 2d at 254. Nevertheless, we accord substantial weight and deference to an agency's interpretation because agencies are an informed source for ...