The design approach consisted of treating the addition as a series of landscaped walls that create a plinth to showcase the castle, rather than compete with the original building. A custom mix of local cement was used for the exterior walls and flooring of the museum.
The orientation of the addition meant there is no back of the building, as it is visible from both residential streets that face the museum. Access is provided from both the front of the historic museum and the new addition, to accommodate deliveries for events and changing exhibits.
The walls step back to help reduce the overall visual height of the building and provide views for the learning center and gallery.
To ensure the new addition didn't compete with the historic museum, the height was kept to a minimum. The ceiling in the gallery is 16 ft. tall, with 2 ft. of space above for mechanical equipment.
Vertical lines on a decidedly horizontal addition complement the vertical element of the historic castle. Vinyl and lumber form liners were utilized for the poured-in-place concrete, combining modern and traditional techniques to create the same textural effect used by Henry Mercer on the original museum.
The new Great Hall serves as open gift shop, point of sale for tickets, orientation, large catered events that can spill out to the terrace, access to the changing exhibition gallery, learning spaces, public amenities, and new access to the historic galleries.
The Learning Center functions both as a place for formal presentation as well as a hands-on learning environment for youngsters. Support spaces serve for material and chair storage and can be either open or closed from the main space.
Windows and glass skylights in the grand entry hall contrast with the castle’s heavy appearance, preparing the museum goers for the ascent up to the main space of the original castle.
The concrete floors were finished with a natural process, RetroPlate, which uses no solvents or VOCs.