ROCKLAND – The stately, graceful Knox County Courthouse is getting a younger, more fashionable roommate.

Finishing touches are still being made on the $4.5 million annex, and evidence of a few leaks was apparent Monday, but much of the 25,000 square feet is already occupied.

Landscaping, curbing and paving should be wrapped up by mid-May, said Norman Ness, who supervises facilities for the state court system. Furnishings for courtrooms and conference rooms also should arrive by then.

A stunning mural of the northern sky at night above the second floor courtroom visible from the outdoors will be painted in June by artist Mark Wethli of Brunswick, said Scott Simons of Scott Simons Architects of Portland.

The Percent for Art component of the project includes the mural, two paintings of Rockland scenes by Sam Cady of Friendship and three paintings with calligraphy by Jan Owen of Bangor.

Owen’s pieces will have excerpts from the Declaration of Independence, U.S. Constitution and the Maine lawyers’ oath, Simons said. The works by Owen and Cady will be done later this summer, he said.

As of late April, two courtrooms in the addition were being used for District Court and Family Court cases, and a mediation room also was open for business.

The two-story brick structure blends with the original courthouse, which was built in 1874. Overall, the addition consists of two courtrooms, two judges’ chambers, a public elevator and a secure elevator, district attorney’s office and county commissioners’ meeting room and five conference rooms, Ness said.

The new courtrooms have plenty of woodwork, the stairways have thick glass panels built into balustrades, the hallways are decked with natural wood columns, and the floors are covered with sea-green tile.

Additional footage at ground level accommodates a sallyport where corrections vehicles can drive in to drop off or pick up prisoners in a secure environment. From there, the inmates are taken to a courtroom via a secure elevator, Ness said.

For months, court clerks have been working amid construction activity in a greatly expanded office space, located between the existing Superior Court and the two new courtrooms.

Ness described the new courtrooms as being multipurpose rather than strictly for specific courts. District and Family courts will share the rooms and, in some cases, Superior Court may use the newer courtrooms, he said. For example, arraignments may take place in the smaller courts because of new security systems.

As for budget, Ness said, “we are very tight at this point.” He thought the project would not exceed the overall cost of $5.5 million, $4.5 million of which is construction costs.

The state hopes to have a joint open house with county commissioners sometime in June, he said.