1. Intent of Contract. The intent of the contract is to provide for the construction and completion in every detail of the work described. The contractor shall furnish all labor, materials, equipment, tools, transportation, and supplies required to complete the work in accordance with the plans, specifications, and terms of the contract. 2. Alteration of Plans. The city reserves the right to make, at any time during the progress of the work, without notice to the surety, such increases or decreases in quantities up to 25% of the total contract price for the project and such alterations in the details of the construction, including alterations in the grade as may be found necessary or desirable. Plan changes may include the addition, elimination, reduction, or increase of any one or more items or units. If the plan change results in the increase or decrease of the quantity of a major item by more than 25 percent, the city may require negotiation of the unit price for that portion of the major item above 125 percent or below 75 percent of the quantity stated in the contract. A major item, for the purpose of this section, will be considered to be single bid items or if noted elsewhere a group of items or separate schedules, the total cost of which exceeds 15 percent of the total contract price for the project. For contract plan changes involving work for which there is no unit price, city and contractor shall, if possible, agree on a fair unit price or sum to be added to or deducted from the contract, as appropriate.