The phrase "adjoining this" is correct and usable in written English.
It can be used to refer to something that is next to or connected with something else, often in a formal or legal context.
Example: "Please find the documents adjoining this letter for your review."
Alternatives: "next to this" or "attached to this".
Adjoining this, our physical coordination.
Briggs Beall and myself were in a room adjoining this one.
An entire apartment adjoining this one, facing the back, is also for sale.
Adjoining this is the ancient cathedral (rebuilt 1099 1118) which contains a 12th-century mosaic pavement made by Magister Paulus.
Adjoining this tract, both on the east and on the west, there have been laid out restricted residential plats upon which residences have been erected.
Adjoining this funky canteen there is also a far more formal, chic restaurant, with a separate and much more expensive menu.
For anyone who has ever been even slightly moved by the image of a tall mast, purposeful hull or sweeping sheer line, the view of the fleet assembled at the docks and mooring field that adjoin this salty town is simply staggering.
Just as the group reached the southwestern corner of the square, there was another tense few minutes as demonstrators again stood in the middle of an intersection, this one adjoining the grand old Biltmore Hotel, where top Democrats and aides to Mr. Gore are staying.
This location, adjoining the University of Chicago campus directly to the East, makes the sculpture a contributing structure to the Washington Park federal Registered Historic District, listed on the National Register of Historic Places.
The best of Brecklands * Lakenheath Warren: viewed from the adjoining bridleway, this is one of the best surviving examples of the traditional, open Brecks heath landscape.
Computer firms may expand from a market they dominate and seek to establish a monopoly in an adjoining one; this was the issue in the case of Microsoft's Internet Explorer.
