Seems impossible to find any height data for Workers House in Kampala:
http://skyscraperpage.com/cities/?buildingID=94142
When I did the drawing I used the Emporis.com general estimation for 20-floor buildings.
I did find data for the year of completion though: 2001.
Sources:
http://www.roko.co.ug/www/rcl/nssf.html (The construction company)
http://www.newvision.co.ug/B/D/525/1/9321 (age-old news story about the opening, published in may 2001)