After the earlier plans for a museum house on the Ellenwoude estate went awry, Helene wants to further develop this idea on the Veluwe. In 1918 Berlage presents his sketches for a huge building with a living area and exhibition spaces. The central hall would be more than twelve metres high with a crystalline ceiling of coloured glass. There is a sitting room for the master of the house and one for the mistress, a dining room and a living room, all connected with the grand hall and the Van Gogh gallery by a single door.

But the design is never realized. On 1 September 1919 Berlage terminates his contract with the company. The relationship between himself and Helene has come under increasing pressure and Berlage is tired of her interference in his designs. She writes to her son Bob in 1921: ‘For me, he was always the little man, the irritable man, the ugly unpleasant character, but – the great artist!’

Berlage’s successor is the Belgian architect Henry van de Velde. On 1 February 1920 he receives a two-year contract as the Kröllers’ personal architect. He presents the first drawings for the ‘Grand Museum’ in the autumn. ‘Sam, the museum will be beautiful!’, writes Helene to her friend, ‘You will be amazed when you see the plans. They far, far exceed my expectations & I believe they far exceed anything comparable that has been built or designed thus far’.

In 1921, construction begins at the foot of the Franse Berg in Hoenderloo: a railway line is even constructed to transport the ready-hewn blocks of Maulbronn sandstone from Germany to the Veluwe.

Müller & Co did good business in the First World War, when iron and coal was in high demand. But since then, the business has stagnated. Under Anton’s direction, the company accumulates massive debts in a short period and thus experiences serious financial difficulties. In 1922 he is forced to halt the construction of the museum and Helene informs Bremmer that no more works of art can be purchased. She writes to Sam: ‘When I pass the site of the museum now, it feels like an open grave that awaits its corpse. […] Sometimes I still cannot believe it, that it will not happen there. I am still waiting, as if for a miracle’.

Helene asks Van de Velde to further develop his design. In 1926 he presents a package of 1,000 sketches, drawings and descriptions.

Despite the setback, Helene continues working on their ‘culture park’, which is now completely enclosed. Helene works with Henry van de Velde on the development of a ‘museum park’ near the Franse Berg, for which she has the old path structure extended and rhododendrons planted. John Rädecker is commissioned to make several sculptures and she talks with Van de Velde about new monuments. She also places a 17^th-century sculpture by Rombout Verhulst and two Buddha statues in the garden. Gradually a park-like environment is created, intended as a natural entrance for the proposed ‘Grand Museum’.