Occasionally when performing home inspections we run across homes with ivy growing up the walls. Thus ensues the conversation of the good verses the bad. Whether your house is built with brick, stone or wood it will likely suffer from being covered with vegetation.
Vegetation growing on and against you house can trap moisture. Normal moisture has always caused problems. The lack of sunlight to help trapped moisture to evaporate can result in all sorts of damage environmentally and structurally resulting in deteriorated wood and damage to softer masonry products and crumbling/failing mortar.
Ivy and vines are living, breathing plants and their growth and thus when growing up the side of your house can result in displacement to some elements of the structure. Vines like wisteria can be even more destructive yet others have tendrils that are much smaller and can penetrate even the tiniest cracks.
Even when growing on a solid and well maintained brick wall over time it will hamper required preventative maintenance and the invasive roots can eventually cause considerable damage. They can also conceal and provide shelter for potential wood-destroying insects and other pests.
It is recommended that all Ivy and vines growing on the side of a structure be removed and vegetation be trimmed back and away. The best want to remove ivy is to cut a few inches out at the bases of the vine. If you want to completely kill them go to your local lawn and garden center or hardware store and buy vegetation killer. Spray it on the freshly cut vines. Let the vines dry out. They will likely start to fall off but whatever you do have to pull off will do less damage with a dead vine than a live one.