Possibly the different uses of the buildings dictates the overall shape. One building has a curved roof because of the 'green' natural ventilation system employed. Another building with few windows has a large lecture room with tiered seating overlooking, but separated by a glass wall for hygiene reasons, a dissecting room. The library needs lots of windows to let in the natural light but it has horizontal slats to reflect the sun when it is low in the afternoon sky. I think the differing designs makes it interesting.
Opinions can differ as to whether or not there should be uniformity of general style or a variety. A large housing estate by the same developer can be a nightmare to find your way around and, even more importantly, find your way out of it!
Very few houses on Brookmans Avenue, Kentish Lane, etc had the same architect. I prefer these individual houses instead of a street of clones. But even a street of mainly the same style, as on Swanley Bar Lane, can alter over the years due to different extensions, gardens etc which have created individual houses.
The council does usually refuse designs, both for houses and front boundaries, that are out of character with the street scene although there are a few notable exceptions. Don't ask me to name them - use your own eyes.
A house on Mymms Drive has just lost an appeal because the proposed front boundary wall, railings and gates would be out of keeping with the open and spacious character of that road. I hate the 'Fort Knox' attitude that is creeping in, with massive front walls, metal fencing and metal gates operated by remote controls. This is a city mentality that has no place in a village. Many of those on a certain street were built without planning permission and the time limit has passed for the council to take action.
Whew, I feel better for that rant.