Rentable Square Feet-Building means the square feet comprising the building on the Premises which is estimated at fifty-four thousand, four hundred ninety (54,490) square feet involving office space and manufacturing space excluding the covered shed on the Premises. On or before May 1, 2006, Mebane and HPC shall jointly participate in the measurement of the building to determine the Rentable Square Feet-Building comprising the building. All measurements shall be made from the outside walls of the building, without deduction for any interior columns, stairs, equipment or any other interior construction. In the event of a dispute as to the determination of such square footage, such dispute shall be submitted to arbitration pursuant to Section 16.9 of this Lease. Pending the final determination of the square footage, the rental shall be based and payable on the estimated square footage set forth herein. The final determination of the square feet shall be retroactive to the Commencement Date in computing rental payable hereunder and adjustment between Mebane and HPC shall be due with the next regularly scheduled payment of monthly rental hereunder.