From England:

by Car, head for Perth. Either use the A9 after Perth and turn off at Aviemore heading for Elgin, or Head for Aberdeen and West after towards Keith.

From Mainland Europe:

Easyjet:

Easyjet fly at low cost direct from all over Europe to Edinburgh For example Basel to Edinburgh takes two hours and in low season has very low fares. Easyjet also fly to Inverness and Aberdeen usually after a change at Gatwick in London. The direct flights to Edinburgh and Glasgow save changing, and a hire car from there is a good option to drive North to the house.

Ferry.

Zeebrugge to Hull in England. Drive North to Scotland and head for Aberdeen. From there follow the main Aberdeen to Inverness route. from the ferry port in Hull to the Granary can be done in one days drive.