Leakage in a new home

Questioner

On February 1, 2021, we received the key to our new house and moved in on February 20. On February 28, we discovered a small leak in the corner of the extension. We had not discovered this before and have the following explanation for it. A few days before we discovered the leak, we had a new oak window sill installed and the water droplets were immediately (unfortunately) clearly visible on it. Before that, there was a smooth white window sill and there is a heater under the window sill. I think that the drops that were in front of it were not noticed, because they dried up again quite quickly. And that is also the explanation that the previous residents did not see this either. The container that is now underneath also occasionally has about 10-20 drops in it, but can be dry again a few hours or half a day later, because it has dried up. Now the previous residents indicate that it is our problem, because they did not have this leak. I disagree, because I am convinced that it was there before. Their real estate agent indicates that it is probably due to the frost/snow, but that is nonsense, because the snow had been gone for 2 weeks and there are no pipes or anything. In addition, it had not rained for a week, so it was drops of condensation water on the underside of the wooden panel on the outside of the extension. Our handyman looked at it and sealed it up, but found the wooden construction that was there, not very safe anyway. Then the handyman of the previous resident looked at it and could not find it. He only made some adjustments to the rain pipe, but that did not help either. Their handyman also carried out maintenance on the extension a few months ago, but what they adjusted has nothing to do with the leak, they say..... Anyway, are these our costs to repair it properly or the costs of the previous resident?

Lawyer

The nature of the defect is not sufficient to appeal to hidden defect in the purchased home (then the requirement is that you can no longer use the house as a home). However, you should try to hold the seller liable for at least half of the costs on the grounds of mutual error; otherwise, please contact me by email?