The architect should be extremely careful that he has authority from the owner before assuming to bind him in any way. It is desirable to have such authority express and definite. In important matters, or with unreliable clients, written authority should be obtained. The mere fact that the building contract provides for some action by the architect as agent of the owner, may be evidence of authority from the owner to the architect to take such action on the owner's behalf, but is not conclusive evidence of such authority. In other words, if the action of the architect which is contemplated by the contract is action as agent of the owner, then the architect needs authority from the owner before taking such action, and the provision of the contract may not be enough to show such authority to have been granted. If, however, the action of the architect contemplated by the building contract is action in a quasi-judicial capacity, no authority from the owner is necessary to empower the architect to take such action. His action then derives its force not from the authority of the owner but directly from the contract itself. It is sometimes difficult, as has already been seen, to tell in just what capacity the architect acts in a given function, and considerable caution is necessary on his part not to assume an authority as agent which has not been granted, and so render himself liable without so intending. To illustrate a function of the architect often pro vided for by the contract, but requiring authority by the owner, we may take the matter of ordering extras or alterations, where such ordering is provided for by the contract between owner and contractor.

For the purpose of showing the ordinary limits of the architect's powers, attention is called to certain acts for which he is not empowered. In the absence of special authority, the architect has no authority to modify the building contractor alter plans or specifications, to extend the time for completion, to change the original contract, to bind his employer for extra work, to accept an inferior class of work, to waive an agreement by the owner as to the terms of payment, to excuse the contractor from any of the provisions of the contract, to employ another to do work which the contractor has undertaken, to substitute another for the original contractor in the performance of the work or the payment therefor, to supervise the letting of sub-contracts and the employment of workmen, or to consider, in making up his statement of the accounts between the owner and architect, any accounts outstanding in other matters between the parties. The architect cannot, without express authority, bind the owner to pay for work or materials. He is not the owner's agent for the purpose of receiving notice of an assignment of payments due from the owner.

Where the architect is for any purpose the agent of the owner, there will, according to the general rule of agency, be various implied powers necessary to carry out the purposes of the agency. The extent of these will vary with the facts of each case. If the architect acts as superintendent of construction, the powers may be quite extensive. As circumstances may enlarge an agent's powers, an architect might in an emergency be authorized to take extraordinary steps for the protection of the owner's rights or property.

In general, it may be repeated, the architect should be careful not to exceed his powers, and wherever practicable should have his authority definitely stated in writing. One regard in which architects sometimes exceed their powers may be especially mentioned; that of incurring unnecessary expense for artistic reasons.

Although an architect may have authority in a given case to bind the owner in ordering necessary materials, furnishings or extras. he is not necessarily justified in increasing the expense therefor, on grounds of taste.