Uganda House was started as one of the UPC income generating companies, the others being Uganda School Supplies, the People Newspaper, Ugationers etc under the Milton Obote Foundation supported by a foundation of the Social Democratic Party of West Germany.
By the time of the 1971 coup the building was half completed and Amin was rightly advised by his first legendary cabinet to change the foundation and its companies, except the People Newspaper to a trust, Thus it was renamed the Uganda National Trust. The late Mr Sempira was appointed the General Manager.
One of his immediate tasks was to mobilise funds to complete the building. Being that it was a very viable business, a consortium of finance companies including Ugadev (UDC), National Insurance Corporation, etc put up funds and the building was completed in 1976.
What I am not sure about is whether the UPC later repaid those companies the loans.
I have never heard of anyone complaning that their salaries were deducted to pay for the building of Uganda House.