Scotland's national gallery, and its collections of Scottish art, are to be revamped and modernised, the galleries director general has revealed.

John Leighton said that following the £17.6 million redevelopment of the Scottish National Portrait Gallery, the next major project would be upgrading the National Gallery building on The Mound.

His comments came as James Holloway, director of the portrait gallery, which will reopen in November, said: “We will be handing back to Scotland their family album, their historical DNA. This is a gallery about Scotland, Scottish history and Scotland’s place in the world -- such vital subjects right now.”

Mr Leighton told The Herald that the building on The Mound needed attention as it has been 20 years since the gallery interior has been refurbished. He has in the past expressed his disappointment over the status of its Scottish collections, which are currently in the gallery’s basement.

After hailing the portrait gallery project, which is on time and on budget, Mr Leighton said the national gallery and its collections would now be a “top priority”.

When Mr Leighton joined the National Galleries of Scotland (NGS) in 2006, he said the display of Scottish art in its windowless 1970s basement resembled an “apology” and he was “deeply unhappy” about the displays.

The National Gallery is now under consideration because the Portrait Gallery’s extensive redevelopment is almost complete, with public and exhibition space increased by more than 60%.

Large spaces previously used for storage have now been opened up as new galleries, there is a larger cafe and shop area, a lift that can transport more than 40 people, new education and learning centres, as well as a new entrance area.

The refurbishment of the gallery, one of the NGS’s most popular sites with local and national visitors, has been overseen by the Glasgow-based architects Page/Park, and Mr Leighton said the galleries hope that visitor figures will climb from around 200,000 a year to 300,000 after the reopening.

There will be 17 opening displays, including Reformation to Revolution, David Hume and Allan Ramsay, Women of 19th-century Scotland and the War at Sea in World War One.

In the new gallery space, once used for storage, there will be a display relating to modern Scotland, including the rise of Scottish nationalism in the mid-20th century and the growth of the Scottish National Party.

There will also be displays relating to the Jacobite cause, the display of tartan in classic portraits, and Thomas Annan’s photographs of Glasgow.

The public will, for the first time, be able to access all three floors of the much-loved building in the New Town, designed by Sir Robert Rowand Anderson, which opened in 1889 as the first purpose-built portrait gallery in the world.

The gallery’s visitors will see more displays of its vast collections -- 3500 paintings, sculptures and drawings, 25,000 prints and 38,000 photographs.

The gallery has a new mezzanine level to accommodate office space and a lunch room for schools as well as the most significant change -- a suite of five top-lit galleries on the upper floor.

One of the new galleries will be dedicated to photography, with three photographic exhibitions a year -- the first will be the Romantic Camera, showing the relationship between Romanticism and photography from the 1840s to the present.

In perhaps one of the most noteworthy changes at the gallery, the Society of Antiquaries Library has been moved in its entirety from the second floor to the heart of the first floor. There will be a public area and a by-appointment research area.

The NGS is also changing its corporate image.

It has invested £30,000 in a new emblem and badges for the portrait gallery, Scottish National Gallery of Modern Art and Scottish National Gallery.

Mr Leighton added: “The new Scottish National Portrait Gallery will be a superb setting to showcase rich traditions of Scottish art and photography; it is also a forum where issues of history and identity come to life through art; perhaps, above all, it is a place where individual and collective stories and memories come together to create a fascinating and imaginative portrait of a nation.”

The NGS still has a further £1m to raise for exhibitions, outreach and education programmes.