changes to register after a new build is undertaken on land

We have recently completed a self build. The land was registered in our name when we first purchased it in 2019. the new build property has been named XX with the local authority but is not currently linked to the original title. My questions are:

1) Do we need to do anyhting to the original title to show a house has been built and we own it, or is the original title sufficient?
2) Do we need to link the new name XX to the original title (at the moment the new name has appeared in online searches but has an address only with the existing title appearing separately.

Thank you

Andrew - 1) No as the general boundaries/registered extent are unchanged. That's what we register and not what is built on the land
2) You don't 'need' to link the new address to the registered information but you can do

A registered proprietor or their conveyancer can write to us or complete form AP1 to change the property description. For example, to change the property's name or to include a second postal address

You need to send us evidence from the street naming and numbering department of the Local Authority. Royal Mail documents are not acceptable as their delivery point address description can differ from the Local Authority registered address.

When submitting your application, please remember to tell us the address you would like a copy of the updated register to be posted to upon completion. And a covering note to explain that a second property has been built on the title

There is no fee for this application

Where to send your application

HM Land Registry address for applications.

Thank you once again for the detailed and prompt response.