What is the test for determining the quantum of damages for intentional concealment of a latent deterioration problem in the siding of a house?

Applying Unrau v. Gay, supra, the trial judge concluded that the defendant had lulled the plaintiffs into making no further inquiries by alluding to his knowledge and expertise in the area of house construction, by specifically stating that the house was of sound construction and by stating that any apparent problems were of no importance and due to normal wear and tear. The judge found that the defendant had intentionally concealed the fact that the siding had a latent deterioration problem of which he was well aware. In determining the quantum of damages the trial judge took into account the expert testimony provided to him as to the differential land values between a house that lacked the defects that the property in question had, versus that which the parties had dealt with. He specifically ruled, however, that the mere difference between the two values was not the proper measure of damages, but that a factor that took into account the inconvenience caused to the purchasers by the concealment of the defendants would also play in to the measure of damages.