Growing up the front of my old house was an established Ivy tree, originally planted to make the front look pretty; it did not deter this plant from literally taking over the entire front of a terraced house.
I had to have it professionally trimmed every year as it grew upwards and onwards and outwards getting thicker and denser covering a bedroom window (if we allowed it) and crawling on to the roof.
So why keep it then?
It provided an entire housing estate for all the little sparrows. There were lots of nests in it and I am a bit precious about stuff like that
Sparrows had gone into a decline at that time, as had starlings and other birds.
When I sold the house, the marketing photos were simply lovely. The Ivy did not stop people from looking, in fact it actually helped to sell the place.
Early in the summer of 2011 we had some really windy weather. The Ivy by now had had it's yearly trim, but the guy who did it said his ladders were not long enough to reach the pinnacle of the roof, and a gust of wind blew underneath it creating a large gap.
We got up in the morning to find the whole of the Ivy had peeled off the front of the house in one piece and was in a massive roll down my garden and driveway narrowly missing the car.
All the sparrows had absconded. Talk about eviction 
We had to chop it up and cart it off to the tip. It took a long time to sort the mess out. My car was a right mess inside and full of spiders. My daughter refused to go in it 
Then I had to have the front painted, since I had already sold the house. The house was half brick - half render.
The new owners were pleased - said it saved them a job and they would have taken it down, but what was the most amazing thing of all was there was no damage to the mortar on the bricks and everyone who previously said the Ivy was destroying my house had to eat their words x