The hall, has been a Grade I Listed Building since 1952 and has been called "the finest house of its period in Lancashire". It is built of sandstone and stuccoed brick, in a traditional Palladian design with the entrance on the north side and the facade on the south. The landscaping was designed to make the most of the uninterrupted views of the rolling hills across to the Pennines. An important feature of this was the ha-ha, used to keep the grazing animals, so important to the landscaping, away from the formal lawns, with a barrier that was all-but invisible from the house.
The state rooms include the Library, the Music Room, Dining Room, and upstairs, a rather rare Etruscan Room. The rooms of the hall were exquisitely finished by the finest artists and craftsmen of the period, with most of the furnishings and mahogany doors being made by Gillow's of Lancashire. Most of the decorative paintings, the Pompeiian Cupola Room and the case for the 18th century chamber organ built by Samuel Green in 1790, were the work of Italian artist, Biagio Rebecca. The organ fills one wall of the Music Room. The ornate plasterwork was created by the firm of Joseph Rose II of York.
There are 13 rooms occasionally open to the public in the central core and east wing. Manchester City Galleries restored the decorative detail in the 1980s and early 1990s. The ground floor rooms on the north east front have been converted to an expansive space that houses temporary exhibitions. The first floor rooms include the Cupola which was originally Lady Egerton's dressing-room. The room was styled in the 1770s "Pompeiian" style with mirrored walls and a domed ceiling and there are only three such rooms left in Britain.
The library was remodelled by Lewis Wyatt in the 1820s. A painting depicting one of the horseracing meetings held in the park can be seen here. The library is now licensed for civil partnership and wedding ceremonies. Heaton Hall's collections are managed by Manchester Galleries. Photography is not permitted in the hall but a collection of photographs of the hall's interior can be seen on the Manchester Art Gallery webpage.