you need something else to worry about .. though to be clear.. knowledge is power..a nd the search for it is approved ... but just dont worry about it ...

why do you think a hole will result from dead wood ... the dead wood will turn to humus.. and eventually soil ... not a hole ...

perc your soil.. and find out if you have a drainage issue ... most trees have no real impact on soil moisture ... and planting trees in low areas to take up water is a myth on some level ....

ken

https://duckduckgo.com/?t=ffab&q=perc+garden+soil&iax=videos&ia=videos

Unless you have damp soil under you foundation, it's unlikely your avocado roots have spread there. Roots seek moisture. Houses blick moisture. Further Avocados have shallow root systems. It's more likely that your house us preventing the avocado roots from reaching a broad enough range to support growth than it is that your avocado is threatening your house.

Just to be clear, the tree is about 20ft high and base of the tree is right next to the house. I was just not wanting to create a problem where there wasn't one. Unfortunately, the poor tree has been damaged by insects and cannot be saved. Thanks to you and to Ken for you comments!