Critical Review

Tor Valstad in the first part of his article “The Oslo Method – A Practical Approach to Register 3D Properties” gave a brief explanation about regulations and methods to register 3D properties. The Planning and Building Authority is the board that has the task of combining building control, planning, surveying, and land registration since 1992 in Norway. Oslo’s local government gives right to property developers to make all local development plans. The problem came up when the property developers made development plans below the ground.

This problem has a strong relation with the availability of underground map (3D map). For 2D map, Oslo has a good system in digital mapping. All of Oslo’s areas are covered by base maps in 1:500 and 1:1,000. Regularly, the maps are up dated every 3 years with photogrammetric mapping. But for 3D mapping, Oslo’s local government just realized that it was very important since they built “the city’s first underground train way”.

When the local government allowed property developers to develop underground constructions, another problem came up. The problem was about land registration and cadastral system that will be used in these properties. It was too difficult to determine the title and the owner of underground parcel, because this parcel still has a strong relation in law with the parcel above.

In the other parts of his article, he gave an explanation about cadastral system in Norway. The system “is a parcel – based land information system”. National and Local Government had regulations that all parcels had to be connected with their spatial information and its property. In parcel identification, Norway has a unique system. Every parcel is given the name in the digital format. The number contains 12 digits. 4 digits are to identify the municipality and 8 digits to identify the parcel’s number. This system also will be used in underground parcels.

In the last part of his article, he gave a practical approach to overcome the problems. For cadastral surveying, surveyors in Norway are allowed to use sophisticated tools like Reflectorless and Total Station. Then, for 3D mapping they use 3D coordinate system. Besides measuring 2D aspects (X,Y) surveyors also measure height to get 3D system (X,Y,Z). But these methods still need some studies for testing the effectiveness of these methods, because it is not easy to make underground maps and do underground construction. Related with law aspect, some regulations from The Government should be released to support technical aspects.

The same as our problems here, we find many difficulties to overcome in registering 3D properties. The first problem is the availability of accurate 3D registration maps. I think it is very difficult and needs a long time to do this. The second problem is the suitable regulation for 3D properties. Amsterdams Arena Football Stadium in Amsterdams could be a good example. There are an underground railway station, car parks and malls below the stadium. Amsterdams’ local government made special regulations on this building and spent many years in development studies before they built this building. It also happens in Indonesia, when Jakarta’s local government wants to build Monorail. Even though the Monorail is still under construction, we haven’t heard yet about the regulations.

In practical approach about these problems, I truly agree with Tor. 3D coordinate system has to be used in order to make 3D map. Because in the future, we have to transfer this system into 3D Land Information System. The other advantage in using 3D coordinate system is to coordinate transformation. Because if we have already used 3D coordinate system, it is easy to transform the coordinate into global system.

For using sophisticated tools in measuring underground constructions like Total Station, Reflectorless, I think it is a must, because it is quit different if we do land surveying and underground surveying. Especially in cadastral surveying, good accuracy in measuring land is a must. So, to do underground surveying of areas with a lot of disturbances, and had to use sophisticated tools. The other sophisticated tool that we have to use is Global Positioning System (GPS). This instrument is very helpful, because we have to make a coordinate reference system in the ground if we want to do underground mapping. Besides using sophisticated tools, I think The Planning and Building Authority should use standards of accuracy in every land measurement.

Overall, I like all of the ideas from this article. Tor gives me another perspective to approach how to register 3D properties. But the most important things that he stated were the parcel identification and making database system in land registration, although he was still confused as to which one to do first, the 3D construction and 3D mapping or making 2D and 3D database.

Building a database system and making 3D maps have to be done together. But I think these actions should be followed with strong regulations from government. Yes, we commonly know that land conflict always comes up from unclear rules and mistakes in conducting data from surveyors. But we can handle it with strong regulations and good technical aspects.