DISCLAIMER: The data used to demonstrate a real estate transaction is entirely fake. No personally identifiable information is available in these datasets.
Project Background
Land administration requires access to data from various sources to fulfil various use cases. To support the retrieval of information for these use cases, it has been proposed that a portal be developed to integrate land administration information. The integration of this information is based on the implementation of the Land Administration Domain Model (ISO19152) as an ontology. The ontology is available here and the integrated dataset is available here. The development of the ontology was done as part of a student project with the TU Delft and continues as a research and development project.
One of the use cases for the development of a standards-based portal for integrated land administration information is to support the process followed when transacting real estate. In the Netherlands, several steps are included in this process and require the retrieval of information from multiple, distributed sources, both open data sources and closed or paid data sources. This is well regulated in the Netherlands and the relevant parties are already able to access and make use of the information in these sources.
An integrated data source improves the efficiency with which information can be accessed by users. Indeed, only two information points are now required from the user in the below demonstrator, the address and the bsn associated with a given building plan application. With this information, spatial plan, law restrictions, personal records, cadastral information and real estate value information can all be retrieved based on a number of easily defined SPARQL queries. Previously, this would have required access to several data sources, each with a complex model and different retrieval mechanisms.
This data story demonstrates the retrieval of data at different stages of the process flow. This is done by querying the information now integrated using the LADM ontology based on a set of questions which are relevant to users of the portal at various stages of the process flow.
Demonstrator Notes:
- The data available in this demonstrator only has the spatial scope of Almere and Zeewolde.
- To test the demonstrator, the following address information can be used as input:
Example 1:
- Name: Wilhelmina Kracht
- BSN: 99473114
- Address: Forum 63, 1315TG, Almere
Example 2:
- Name: Evert Schults
- BSN: 3323109
- Address: Pluvierenweg 9, 3898LL, Zeewolde
1. Preliminary Phase
During the preliminary phase, an exploration of the real estate that is could be purchased is carried out by the potential buyer. There are several steps included as outlined in the following figure.
Figure 1. Real Estate Exploration
In this process flow, several data sources are accessed. Once all the information is retrieved by this seller, a due diligence on the property is carried out which includes the sharing of information between the potential buyer and seller of the property. Should the buyer then wish to continue with the transaction following the due diligence checks, the following stage of this flow is initiated. This is described in the subsequent sections of this data story.
Building Information
Upon initiation of a potential transaction, a real estate exploration process is carried out first on the building object. During this exploration, the following questions are posed:
- What is the purpose of use of the property?
- When was the property constructed?
- What is the surface area of the property?
- What are the current property valuations in the area?
- Are there any restrictions on the property?
The queries below uses the portal to answer these questions. In all cases, the address details are used as input parameters to the queries and the different information required during the exploration is returned to the user.
Technical Note: By clicking on the 'try this query yourself' button, it is possible to see the underlying query defined to support the answering of this question. This a SPARQL query; the native query language used to retrieve information from linked data sources. The query parameters defined for this SPARQL query, the address information, makes it possible for the user of the land administration portal to simply input address information and return this information in a table without having knowledge of SPARQL.
The following query visualises the same results as the above query but on a map interface. By clicking on the geometry shown, it is possible to see the specific spatial plan document associated with this geometry.
Parcel Information
Following the investigation of the building, the cadastral information related to parcels are then retrieved. The following questions are posed:
- What is the surface area of the parcel the property is located on?
- What restrictions are associated with the parcel?
The following query visualises the same results as the above query but on a map interface. By clicking on the geometry shown, it is possible to see the specific spatial plan document associated with this geometry.
2. Sequential Phase
Following the initiation of a real estate transaction, the preparation of a sales agreement is initiated. Following the signing of these documents by all parties, the prescreening of the individuals for financial information is initiated. A large part of this process is not demonstrated in this data story. What is interesting to demonstrate as part of this pre-screening for a transaction is the investigation into the current registered ownership and the existence of any mortgages on the property that is being transacted.
This checking of current registration is done based on access to the BRP and BRK datasets and is required before a notarial deed can be signed. Following the check, both parties sign the deed and the final transaction is completed. The following figure illustrates the final part of the the transaction process.
Figure 2. Pre-Screening Notarial Information
Personal Information and Ownership
In order to carry out the personal information, ownership and final financial check, the following questions are posed to the integrated land administration portal:
- What is the identity of the registered owner?
- What are the person's name, address details, and civil status, and is this information complete?
- Who is the current owner of the real estate being transacted?
To answer these questions, the address information of both the seller and buyer are used as input as well as the address of the real estate being transacted. The following queries demonstrate how these checks can be carried out using the integrated land portal.