I think Melbourne federation square is a good example you can look into. Even in Sri Lanka there are new concepts such as floating markets are used to increase activity in the urban context specially using lakes in the city centre.

Dear Roberto,

In my opinion both. But the mixed use attracts more people. In São Paulo (Brazil) we can mention oldest regions in the history of the city that are still young given the clustering of cultural possibilities:

- "Bexiga" that concentrates many theaters;

- The region of the "Luz", which concentrates museums such as the Pinacoteca and the Museum of Sacred Art.

And more new regions such as Vila Olimpia, with their apartments, offices, shopping malls and show-houses.

Best Regards,

Vanessa

Definitely mixed used. An Iconic architecture can attract people and perhaps tourist to visit it once or twice but if nothing interesting is happening in it or in the surrounding area, then just having an iconic architecture is not helpful to attract more people and more activities. Often in the best examples of urban design, an open space with various types of short-term and long-term activities is provided around an iconic architecture. This enables people view that architecture(either it is historical or not)  from different angles within a mixed-use public space which responds to their basic needs such as sitting, eating, drinking, .... So they (iconic architecture+ mixed-use function together) can actually reinforce attracting people and activities in urban environments.

Most urban architecture is pretty mundane . . . and it seems to work. Extreme architectural statements can seem overbearing in numbers. The Chinese are coming to realize this fact and dialing back on their weird buildings. Private sector investors have known this forever. I once knew an investor who would tell his architects that if the building they were working on won a design award their compensation would be reduced. Of course, this sort of view really upsets architects, because their reputations depend upon being noticed. On the other hand, this might be a device that can align the incentives of investors and architects. 

But there are architectural features that matter. The placement of parking lots and public buildings can create boundaries that minimize negative externalities in a much larger area. In concert with limited access highways, these protected areas can be rather large. These large protected areas can attract commercial and residential activities. So the spatial configuration of certain types of investments can influence other activity levels.

The functionality of buildings can affect the length of their lives. Sometimes it is the flexibility of the designs that influence lifetimes. The transitions between one building and the next that occupy the same space are critical. How costly is demolition? How much time will the old building be vacant and derelict?

In this day and age, many are concerned with the energy consumption of buildings. When we see buildings that are essentially identical on all sides, it makes one wonder if the architect is aware of the issues of orientation on the consumption of energy as well as on the comfort of occupants.

It seems that buildings interact. For example, a building with reflective glass can create energy consumption problems and equipment sizing problems for nearby buildings. Shading can be an issue too. And view. The impact of fundamental property rights as well zoning and subdivision regulations that constrain those rights may be more important that architectural judgments in these regards.

Dear Roberto,

I have recently published a paper in which I studied the effects of mixed use and land-use densities on activity patterns. I measured activity patterns using mobile phone data. The conclusion is that mixed use, high density land-use configurations substantially increase the level of activity and the amount of time during which an area has a high level of activity. See: Jacobs-Crisioni C, Rietveld P, Koomen E, Tranos E, 2014, "Evaluating the impact of land-use density and mix on spatiotemporal urban activity patterns: an exploratory study using mobile phone data" Environment and Planning A 46(11) 2769 – 2785. This is the link: http://www.envplan.com/abstract.cgi?id=a130309p. I can share the article with you if you like.

I can't comment on the effect of iconic architecture, although I would intuitively assume that land-use configuration has a more substantial effect. Then again, I do not have any numbers to back my assumptions here.

This would make an interesting thesis topic.  

Of course we have to make some assumptions about what you mean by 'activity' in an urban context.  Street life, leisure appearance, spending of disposable personal income....is that what you mean?

If so....

my personal view is that iconic buildings generate 'activity' in decreasing proportion to their multivalency, i.e. uses for other purposes.  

The eiffel tower, federation square (just the public open space not the container buildings surrounding it), the pyramids of gizeh, the washington dc mall and washington monument,  the top floors of the empire state building, the roman colosseum, all attract the most people; all have no function other than to attract visitors

on the second tier would be performance venues, object buildings or interiors that are programmed for use only in a single special event which draws large numbers but which is of specific duration:  wembley stadium, sydney opera house, carnegie hall, cathedral de notre dame, nuremburg ring.

on the third tier would be exhibition spaces which draw numbers at the visitor's own discretion, unconstrained by time, but constrained by the object of attention:  bilbao museum, louvre museum, madame tussauds, MOMA new york, disneyland, las vegas casinos.

probably most shopping malls of large size would be on a par with the third tier in terms of generating 'activity' but the 'activity' would be hermetic, not street life.  the second tier generates 'activity' to and from but contains it for commercial reasons during.  the first tier has so little to offer that the sheer volume of people attracted to such places constitutes activity in itself on the way to and from.

According to the Victorian Coastal plan, Victorian enjoy the nature and prefer to have beach and sunshine rather than the concrete city. Compare to Sydney, Melbourne was regard as the garden city, Victorians prefer to keep their city surrounded by parks rather than sky-high buildings. That is also the distinguishing feature of Melbourne compare to Sydney and other cities.