On the matter of Urban Development and Town Planning, there are two things of notes that could lead to minor disasters:
1) Excessive regulations on the part of the city authorities always lead to monotony and boredom.
Aleppo is a very fine example of this. The first building manual was issued on 1972 (if I remembered correctly), it was a small booklet of 25 pages. By the year 2000, its amendments amounted to 400 pages. The strict building code was good to rein in the greedy builders, but it produced the most monotonous city ever built. Have a look here, and here. This is one of the affluent neighbourhoods. It's called New Aleppo. The building code allows for two floors. You see boxes clad in stone (beautifully ornate as it they may be), with balconies all around. The only window for creativity being how to throw around columns at the perimeter. Builders spend six month erecting the structure and then go on for years cutting, trimming, sculpting, beveling and embossing pieces of stone together in tacky intricate designs. It's unbelievably lame and uninspiring. Other areas, where the building codes allows for 5 floors, are even more hideous.
2)Lack of regulations, corruption, poverty or lenient enforcement of zoning regulations could lead to chaos, shanty towns and neighbourhoods with open sewer and unhappy children.
There are many evidence of this. Take the Palestinian refugee camps in Lebanon for instance. They started out as tent cities to host refugees, and when it turned out the stay would be long and the tents won't do, the haphazard building process had started. This is also true for many of the slums around the middle east and other developing countries. The outcome is unpleasant to say the least. The buildings are so bunched up together that natural light and ventilation are a rarity.
Usually, even when an architect like myself makes a statement that is, for some, deemed political (like the cruelty of living in slums and the need to get rid of them), we do acknowledge that the matter is much bigger than the realm of urban planning. Town planners and architect MIGHT be able to tell you what's wrong and what's right. Or how to make a wrong right. but we can't tell you how to get the funds to make it.
So is there must a compromise between heavy regulation and chaotic evolution? I believe there is. There are cities around the world that had developed with the least involvement of city authorities. I'm not suggesting that regulations will always have a negative impact, far from it. But the planner should allow for fair amount of creativity on the part of the architects. Decentralize municipal control and allow communities to organize themselves locally.
This is best seen in an organic development of a city. There will be a focal point, be it a seaport, an airport, a dam, an industrial complex..etc.. And around that focal point the city will grow. Now, imagine if that focal point is linear in shape, like a sea front, and that it takes a meandering course along one side of the city. Now, add to that an array of hills, canyons and winding ridges, all gently sloping down to the sea front. Let's also envision a breath-taking natural scenery of green forests that the city planners and residents are conscious not to utterly murder. Coincidentally, let's suppose that architects and residents are adamant on painting their buildings and houses in an endless spectrum of colors that defies order and challenge the scenery around it for the attention of the beholder.
Finally, imagine cable cares and the first public library in South America.
Imagine the great pacific ocean as an imposing background for all the above setting.
You get Valparaiso!