A witness who is not a mason or mechanic, is competent to testify whether the walls of a house are well built or not.

A person who has engaged to build a house for another in a good, skilful and workmanlike manner, at a price to be paid when the work should be completed, cannot recover the price agreed to be paid, nor anything for the work done, when it has been done in a negligent, unskilful and unworkmanlike manner, and the person for whom it was done has neither accepted the work, nor waived a faithful performance of the contract.

(S. C., 14 Barb. 174; 9 N. Y. 93.)