That’s according to this article which suggests it can add as much as £20,000 to the value of the average home. Second on the list is a room extension which can add an average of £16,069 to a homes value, whilst a conservatory adds around £8233. Smaller improvements such as a new kitchen can add around £5617 and new windows £5265. Generally, however, people need to spend a minimum of £10,000 on a conversion or extension in order to see a return on your investment. Still, it’s interesting reading if you are thinking of doing any home improvements.