The 19th century rebuilding was by George Webster in Jacobean Revival style and subsequent renovations were by E. G. Paley.

"[3] The architectural historian Nikolaus Pevsner expressed the opinion that the west wing is the "outstanding domestic work" of Paley and Austin.

In chronostratigraphy, the British sub-stage of the Carboniferous period, the "Holkerian" derives its name from Holker Hall.

Additions to the grounds were made during the 19th century and included an arboretum, a conservatory, terraces, and a walled garden.

The house was largely rebuilt in 1838–41 for the 7th Duke of Devonshire by George Webster of Kendal in Jacobean Revival style.

Paley and Austin's west wing [7] and the gardens are open to the general public during the summer months, an admission charge being payable.

[10] A series of events are organised in the hall and grounds, including an annual garden festival.

Its entrance front faces the east has a porch placed asymmetrically, which is flanked by turrets with domes and pinnacles.

[3] At each end of the long central corridor in the old wing are spiral staircases, which are contained in semicircular projections.

The contents of the wing include panelling removed from Canon Winder Hall, Flookburgh, a chimneypiece from Conishead Priory, and a pair of Baroque barley-sugar columns.

[3] In the library are about 3,500 books, some of which survived the 1871 fire, and some of the former possessions of the scientist Henry Cavendish (1731–1810), including his microscope.

Paintings in the room are by Claude Joseph Vernet (its companion-piece was destroyed in the fire), Salvatore Rosa, and Douglas Anderson.

[19] At the far end of the entrance hall is a cantilevered oak staircase which is approached through limestone arches.

In 2003–04 a cascade, labyrinth and car park were added by Kim Wilkie, and a sundial by Mark Lennox-Boyd.

[31] The north lodge with its gate piers, standing on the B5278 road, dates probably from the early 19th century and was possibly designed by George Webster.

[32] To the southeast of the hall are stable buildings in a U-shaped plan, constructed in stone with slate roofs.

[35] In the grounds to the north of the hall is a lead statue of Inigo Jones by John Michael Rysbrack, dating from about the 1740s; this was moved from Chiswick House in the 19th century.