As a child, I grew up in a house on a 30 foot lot, the houses were so close, and we shared an eaves trough. The house next door fell into disrepair as it became rental property and the owners decided to sell. My grandfather lived in the house on the other side of the property, so he and my parents together purchased the house and decided to tear it down. One permit required it be fumigated and when we reached the kitchen and pulled down the plaster, the walls were lined with dead cockroaches, hundreds of them. After it was demolished, the property was split in 1/2 and we then had a 45 foot lot. It was so wonderful, we had a yard to play in and grow gardens and flowers. I flooded the side lot in the winter and had a "skating rink" and it was good.
The point of my story is this, why not sell 30 foot residential lots to the owners of adjoining property for $1.00, agree to bundle all required permits for a total cost of $25.00 and if they demolish the property, give a rebate for the cost once the demolition is completed. This could potentially eliminate 100's of "nuisance" properties, which must be maintained by the city, put them back on the property tax rolls.