Sometimes buildings cannot be renovated.  In preservation lingo there is a phrase "demolition by neglect" that is self-explanatory.  There are also times when new requirements are incompatible with the old structure like when the California Dr. firehouse's doors were too small for newer trucks.  Burlingame has worked hard to maintain the look-and-feel with new buildings like the firehouse and the library while meeting new needs.

It appears Hillsborough will do the same with the quaint gatehouse that heralded the entry to the Carolands estate.  Some insight from those in the know states that as part of the rebuilding:

The Town was able to save quite a bit of the slate roof, the escutcheon over the door, and the decorative finial on the roof. They will attempt to re-use what they can, provided it's economically feasible to do so. The finished lodge will look almost exactly like the original. (The door has to be made wider to be ADA-compliant, for example.)
 
Re-building will start in about a month with a goal to having a watertight, if unfinished, building by mid-October.  Landscaping and finishing touches should be done by spring.
 
The donations for the re-building were 100% privately funded. We got roughly 150 pledges to donate, and over 99% came through with the funds when it was time to do so.
 
The Hillsborough Police Department will use grants to furnish the interior with communications equipment for their new sub-station.

It will be a ground-up rebuild as you can see here:

 
And here is a picture of it before it was demolished.  Let's see how close the new one comes to it.