This is a common problem. The tree height/size is all important but i will assume it is mature for now. Roots will be too close and certainly within influencing distance of your drains and home foundations. You say drains have roots in them (I assume you mean in the drainage runs as well as the inspection chambers) and therefore you already have a problem. A drainage contractor CCTV report seems appropriate to attempt to define the extent of the problem as you need to know if your drains are fractured.

To answer the question of whether the tree needs crowning/lopping, or even removal, would need a site inspection to define.

Does your house have damage? Often the damage is not obvious unless you know what to look for (apart from cracking)?

Before you go anywhere – Are you adequately Insured? When was the last time the amount of Rebuild Cost was reviewed?

Can’t say much more based on what you report.

Best of luck – Stuart Parrett