Month: February 2013

Biblio (30) A land parcel map for the United States

30-national land parcel

Most of the countries with developed economies can count on a cadastral system. This is not the case of the USA. The administrative fragmentation, so cherished since the foundation of the country to avoid totalitarian rule by balancing powers, causes that the access to cadastral data, simple on a nationwide scale in France or Spain, requires local knowledge in the United States.

The report by the Congressional Research Service argues that the share of geographical data produced by private and non federal actor is rising, increasing the need for coordination to avoid cost duplication. The most urgent need to implement such a system arises from emergency management (a branch with strong federal involvement), monitoring natural phenomena and climate change, or the real estate crisis and the foreclosure dynamics. Options to organize the system in legal terms are advanced, as well as the potential problems of the implementation of such a system.

I wonder if we will ever see in Europe a continental cadastre, taking into account the sheer diversity of our legal systems.

Barcelona- Bogotá (6)


The old core of Barcelona results from the evolution of the primitive roman colony, even if it is difficult to believe by looking at the urban fabric (the large straight streets come from the Cerdá plan in the XIXth century). In Bogota the traces of the Laws of the Indies, with their grid, is clearer.

In Barcelona the Cathedral (red) and the City Hall (blue) are on different squares, while in Bogotá a single space is shared, with a clear symbolism as it also concentrates the headquarters of the judiciary and the Parliament.

Urban growth shows that the aim to regularity always finds unexpected conditions… a regular fabric is almost impossible.


Barcelona- Bogotá (5)

Floor area (sq m) for residential use in Barcelona and Bogotá, by city block. NO means there are no registered housing surfaces on the block

Floor area (sq m) for residential use in Barcelona and Bogotá, by city block. NO means there are no registered housing surfaces on the block. City Halls are marked by a black circle.

Where do people live? And where do they buy? Answering those questions in a precise way is complex. But it is simpler to know where they could be doing one thing or the other, again using cadastral data on maps at the same scale of both cities. This implies that you will not be sure to find people living in these areas or open retail venues, but that someone is (or should be) paying the tax for these uses in these properties.

These maps are not representing densities, but absolute figures by city block; it is as important to know where the surfaces of these uses are and their magnitude, as knowing where there is no such use.

The firs conclusion is that the intensity of the residential use on central Barcelona is higher than in Bogotá (even taking into account that the city blocks are usually smaller). And it could be a surprise to some, as on many images of the second city you can see some towers, while the image of Barcelona is that of a city of uniform heights. In fact, Bogotá has a larger population, but on a much wider area. What happens is that the average height in Bogotá is less than in Barcelona, and less deep buildings. In Barcelona, 150 years after Cerdá presented his plan to reduce congestion in the city center, and despite having somehow achieved that goal, the new city is still very dense.

Taking a different viewpoint, 2012 Barcelona had 1,6 millions residents (padron, and slightly over 72 million sq m of built residential floor (cadastre); so each barcelonés had on average 45 sq m of housing. Bogotá Distrito Capital had in 2012 slightly over 8,9 million residents (estimates by and a little more than 179 million sq m2 of residential floor (cadastre); each bogotano had on average 20 sq m of housing floor, less than half, which explains the differences in residential density. 

Regarding commerce (as applied by both cadastres, with differences that are not always clear between wholesale and retail), there is a difference and a similitude. The historical core of Barcelona is larger in terms of retail density (concentrating the most affluent populations in the XIXth century grid no doubt helps…), while in Bogotá the area north of plaza Bolivar which concentrates these uses is smaller. The similitude is in the development of the large malls. Despite their sometimes relevant links to public transit systems, they are also car attractors.

According to cadastral data, in Bogotá there are 0,07 sq m of commerce floor for each sq m of residential floor; in Barcelona this rises to 0,188. For each bogotano you have about 1,4 sq m of commerce, and for a barcelonés slightly over 5. 

Commercial floor surface (in sq m) by block. NO means a lack of commercial surface in the block

Commercial floor surface (in sq m) by block. NO means a lack of commercial surface in the block

A: Plaza de las Américas- Mundo Aventura, combining a theme park with a large mall

B: Centro Mayor

C: Centro Comercial Calima

D: L’Illa Diagonal

E: La Maquinista

F: Diagonal Mar (the lot with the highest cadastral floor surface in Barcelona, 107.000 sq m)

Corte ingles pcatalunya

G: El Corte Inglés on Plaza de Cataluña, a Department store linked to the historical core

Barcelona- Bogotá (4)

Agora Bogotá (Daniel Bermudez+ Herreros Arquitectos )

With a FAR below 2 (the average in the area, altought with different building types), the Agora center will be a conventions facility by carrera 40 and the Corporación de Ferias in south Bogota. The project can be seen on . The project will transform an industrial site on the edge between industrial and housing areas.

Where the Diagonal meets the sea: the Forum 2004 area, in which is the Barcelona Conventions Center

Where the Diagonal meets the sea: the Forum 2004 area, in which is the Barcelona Conventions Center

The Forum 2004 in Barcelona has a large concentration of towers, marking its landscape; yet the FAR in the tower area (under 3) is not as high as behind the towers, on the much lower Diagonal Mar mall, which gets to 5 as a mall is a much more compact building.

Barcelona- Bogotá (3)

Gaudí on Paseo de Gracia, on a block with a 5,5 FAR

Gaudí on Paseo de Gracia in Barcelona, on a block with a 5,5 FAR

The FAR (floor-area ratio) divides the surface of the built floors in a lot by the lot area.It is not easy to know the density of a zone at first sight, as it depends as much on what is built as on what area you use to measure it. So, a tower can have a density measured over its lot which is lower than that of a more conventional block of lesser height. Even on a block, courtyards can have variable dimensions, so it is not easy to grasp that number from the outside. And this is without taking into account the film “La estrategia del caracol” (the  strategy of the snail), by Sergio Cabrera (1993) and his vision of the “shrinking densities” in Bogotá…

Density by block in central Bogotá and central Barcelona

Density by block in central Bogotá and central Barcelona

Residential towers near Diagonal Mar in Barcelona, FAR 1,7 on cadastral parcel

Residential towers near Diagonal Mar in Barcelona, FAR 1,7 on cadastral parcel

Plaza de Bolivar, Bogotá. An area with a FAR around 3 m2/m2. Image by Richard Lozin in Panoramio

Barcelona- Bogotá (2)

Barcelona (City Hall on the red box)

Barcelona (City Hall on the red box). The arrows indicate a continuity of the urban tissue in neighboring municipalities, whose density has not been taken into account

Density can be explained in diverse ways. Here you can see, according to cadastral data, the gradient of the floor-area ratios by contour lines. The kernel calculation does not give show the precise density value, but a more graphical result for large areas.

In Barcelona you can see that the most common density in the urban core is 5,5 (substantially higher than that devised by Cerdá in his 1860 extension plan). The city has an urban tissue whose density is quite homogeneous, surrounded as it is by mountains and the sea and as the core of a larger metropolitan area.

In Bogotá the density dispersion is higher. The extreme areas are located in many cases closer to the mountain ranges

Bogotá (City Hall on the red  box)

Bogotá (City Hall on the red box). The city extends North and south along the valley

Barcelona- Bogotá (1)

Torres del Parque (a building by Rogelio Salmona), image in Panoramio by Jose Daniel

Two cities on two continents and two different contexts. Barcelona on the Mediterranean sea, despite the crisis with a socioeconomic structure closet o the European average, and Bogotá surrounded by Andean mountains and with a social structure corresponding to a growing Latin American country. This week I propose an excursion around their urban tissues according to their density, that indicator that drives urbanists mad and that is looked for or rejected by people according to the conditions.

For this cadastral data have been used to draw density isolines allowing a parallel view.

Sierra de Collserolla as seen from the Sants Station area in Barcelona

Sierra de Collserolla as seen from the Sants Station area in Barcelona

Biblio (29) Vedado, Havana

And now for a singular plan by many standards. El Vedado is a municipality in metropolitan Havana whose urban layout can be seen as an exemple of the innovative projects of the European urban planning tradition in the XIXth century; and I am fully aware of the fact that Havana is not an European city, but when the plan was aproved about 1860 (nearly about the same time of Cerda’s plan in Barcelona or Castro’s plan in Madrid) it was still a part of Spain, and the planning system is clearly different from the classical colonial grid. El Vedado is indeed a grid, but a different one, which as almost any other plan has been subject to modifications, maintaining despite that many values. I’ve never been to Havana, but the place seems to appear as often as an icon as the Barcelona ensanche appears in Spain, for instance.
It is not a scoop that Cuba has an unfrequent economic system; it is curious that, at least at first sight, the plan assumes a language about investors and development that seems not so different from what we would see overseas.
It is also surprising to see that this plan is organized and explained as a new urbanism document (even when the aproving organ is a people’s commitee). And it has received an honorable mention at the Driehaus Award of the Form Based Codes Institute, a US based organization.
All these are just special conditions. I repeat, I have never visited Cuba and so I have to judge by second hand sources, but the plan seems interesting in many aspects; across the Atlantic it would probably be subject to controversy due to the new towers along the waterfront, but across the Florida straits this woul probably be seen with no suspicion. The historical and analitical parts are well writen (and seem a good intro to the recent history of central Havana), and the bylaws seem coherent. There is a subjacent smell of the New Urbanism transect, and the hands of some Barcelona consultants is also aparent.

The document can be consulted at

Madrid-Buenos Aires (5)

Two urban projects with a story, which shows how complex it is for a city to go from ideas to action.


Secundino Zuazo and Herman Jansen win in 1929 the competition to extend the Castellana, the main north-south axis in Madrid. During the years up to the 1936-1939 civil war the project is not developed, and later the area is developed through partial approaches that no longer have the integral vision, form AZCA (already defined in the 1946 Plan Bidagor) to the leaning towers of Plaza de Castilla. There is a good article by Carlos Sambricio on the Zuazo- Jansen project.

Grain elevators in Puerto Madero

Grain elevators in Puerto Madero

Le Corbusier's project

Le Corbusier’s project

Le Corbusier's night view of Buenos Aires from the Rio de la Plata

Le Corbusier’s night view of Buenos Aires from the Rio de la Plata

Le Corbusier visits Buenos Aires in 1929 and draws the first sketches for an approximation of the city to the Rio de la Plata, transforming Puerto Madero, a string of docks in the central area, in a space marked by its “Cartesian” skyscrapers (reading Le Corbusier’s travels is like remembering Napoleon’s campaigns…). The project is detailed in Paris in 1937-1938, and is even subject to an aborted attempt to develop it by the city government in 1947-1949. The work with a group of Argentine architects (described in « La Red Austral, obras y proyectos de Le Corbusier y sus discípulos en Argentina », by Liernur and Pschepiurca) was essential to the project, even if it was finally not built. Under the presidency of Carlos Menem during the 1990s the idea is reactivated; Puerto Madero has become a new space of centrality, but it is legitimate to think that Le Corbusier would rant, as in New York, agains the small size (in plan ) of the towers. There is an interesting article by Juan Manuel Borthagaray, and the Corporación has a website.

Puerto Madero as built

Puerto Madero as built

Madrid, Buenos Aires (4)


An elegant neighborhood is a space in which architecture has been developed with a greater quality over time as, simply put, its neighbors have had the money to pay for better buildings and they have maintained them. It seems Gangnam-gu is one of the richest neighborhoods in Seoul, but as the city was almost razed during the Korean war, this probably will only translate into an elegant area in the classical sense with more time (at least they have a song…).

The Retiro area in Buenos Aires (some blocks north of Plaza de Mayo) and the Barrio de Salamanca in Madrid (north of the Retiro park) have been built mainly during the XIXth century.

In Madrid the Salamanca area, projected as an integral extension of the city, is, as the Barcelona ensanche (a contemporary project) a tentative to use the grid as a directive principle. It has finally become the most exclusive neighborhood as those that had less money found less expensive opportunities out of the regulated city. And it still is a highly valued area, albeit an extremely dense one; as in Barcelona the original building bylaws where changed allowing a more speculative development. Anyway, there are still two blocks east of plaza de Colón where you can still see the originally projected block model, with large central courtyards, usually “forgotten”.

In Buenos Aires the Retiro district had no special intention to become different by layout or project. How would you differentiate you as a grid in a city that is a whole grid? In fact, it is a less regular grid than that of Madrid (one also adapted to preexisting elements). The neighborhood appears when the then rich citizens look for a new space after the 1871 yellow fever epidemics; Paris is the model for the architecture in a moment in which Argentina, as an agrarian power, becomes an emergent power. From the 1930s it is an entry point for modern architecture.

Avenida Córdoba, Buenos Aires. Image on Panoramio by Franciscovies