Gerard,

The contract you have mentioned should be classified as a 'job contract' within the scope of law of obligations.(Turkish Code of Obligations((CO)Art. 350 etc.

(A) undertakes the construction of the house on a fixed date.(B) is the provider of job.This contract is a 'sinallagmatic'(reciprocal) agreement in which both sides engage in mutual commitments.Here (B) is expected to supply some paint for (A) so that (A) whereby shall perform his debt.

In the general course of job contracts, goods and equipment are supplied by the constructor, yet in your case the employer has assured this obligation, particularly for the painting of the house.
(A) commences the construction late in the day, therefore (B) then may claim the contract shall be annulled ; unless, (A) is to prove that this delay is a consequence of an alleged violation of contract committed by (B) .
This matters are finally to be reviewed by the judge in case of a suit, especially on the faults of both sides.