Is the inquirer obligated to pay compensation for a loss, given that he is a partner with his effort in building a factory after its value was estimated at less than its cost, especially since neither capital nor wages were calculated for him?

If the partner's contribution is only his labor, and he has no relation to the capital, then the loss is borne by the two partners who provided the capital, each according to his share in it, unless the worker was negligent or exceeded his bounds.