First at all, thank you for your stay. I understand you would have preferred to meet in person (me too! i always do if it is possible) but you arrived in the evening when I was still at work and there were two options: make you wait in the street until I finish work or asking a friend to open and give you the keys. I think the second option was better for you.
The building is dark if you don´t press the light button. There is a light button on the left just when you open the building´s door with the word "Light". And yes, the door is a little bit old. From 1850. Isn´t it beautiful how can still work a door that has more than 160 years?