Costs plus contracts are used when the scope is not clearly defined and the onus is on the owner to set certain limits on the contractor`s tally. If some of the above options are used, these incentives are used to protect the interests of the owner and avoid charging for unnecessary changes. Note that cost-plus contracts are difficult to track or harder to track and more supervision will be needed, usually not much risk to the contractor. A construction contract is a reciprocal or legally binding agreement between two parties on the basis of guidelines and conditions recorded in the form of a document. The two parties involved are one or more landowners and one or more contractors. The owner, often referred to as an “employer” or “customer”, has full authority to decide what type of contract should be used for a specified construction period and to set legally binding conditions in a contractual agreement.  A work contract is an important document because it describes the extent of the work, risks, obligations and legal rights of the contractor and the owner. This may be less than what the contractor must pay, since the analysis of the amount of the contract between the contractor and the employer and the price documents between the contractor and the subcontractor will not return. This is due to the fact that exterior walls, masonry, blocks, rendering and rain protection coatings, and the contractor can claim 20 percent of the value of the outer wall for masonry, which is properly complete and covers 20 percent of the exterior walls. However, the cost of masonry does not represent 20% of the value of the exterior wall, as the prices of the different objects are different inside the façade.
In the case of contracts such as measurement contracts, the amount of the contract may not be known at the conclusion of the contract, but is calculated as the progress of the construction on the basis of an agreed measurement method. However, the amount of the contract does not constitute a “fixed price,” even if the contract is referred to as a fixed-price contract, a lump sum contract or a maximum guaranteed price contract.