Using SVG to Provide Customized Housing Solutions for Low Income Population


1 Universidad de Los Andes, Departamento de Ingeniería de Sistemas y Computación

Bogotá, Colombia

{ gbravo, cjimenez, rgarcia, serg-mor }

This work presents the results of a successful project using SVG as representation and integration technology for architectural information. The objective is the development of a catalog of home building solutions for social purposes, assuring architectural quality, legal issues and appropriate technical conditions. The result is called CatArSis, by its name in Spanish “Catálogo Arquitectónico Sistematizadoâ€.

This system must facilitate the getting of building licenses and government grants for low income people, a process actually hard, slow and costly: Building licenses are approved by city delegate offices (called curadurías), which demand a complete, personalized, architectural, technical and budgetary documentation (up to 18 documents) for building projects, signed by registered architects and engineers; this documentation is returned as many times as necessary, until all urban norms are fulfilled.

Costs associated with this process can not be usually afforded by low income people. A phenomenon called “building in own land†occurs: Families acquire a plot, and later build their houses; the building is owner’s responsibility and usually performed by self-construction. Government promotes formal building by means of “Housing for Low Income Families†(VIS, in Spanish) financial programs, granted by the CVP (Caja de Vivienda Popular), where CatArSis was finally implemented. The condition to subside grant is to have the legal building license.

CatArSis has an architectural component providing appropriate VIS home solutions – complete and high quality architectural models, almost ready to be approved by curadurías– and a software component that stores them, searches those that fits a given plot, permits the choice of one of them and finally prints the corresponding, fully personalized, documentation. The owner proceeds to get his building license, then get the corresponding subside and finally to the construction of his house.

The architectural models are rectangular – the usual geometry of objective plots and have the following parameters: The plot dimensions; the topography of the terrain; the location of the plot in the block; the expected use; the standards for architectural spaces; the spatial relationship between facilities and living spaces; and the number of spaces in the facade (1, 2 or 3). Materials, quantities, budget, isolation with neighbors, road allocation and (slightly) geometric distortions of the plot are also considered. For a given set of these parameters, a family of models, differing only in their dimensions, is defined. In the first stage of the project, 7 families and 85 models have been designed and fully documented.

For the software component, the main functional requirement is the customization of models, in order to generate the personalized documentation. To fulfill this requirement SVG was chosen as the representation format for architectural information. The models are drawn, converted to SVG and then imported to CatArSis; when a model is chosen, the customization information (addresses, names, location, etc.) is appended to SVG files and then printed. Non-functional requirements include the easy, low cost of the implementation and usability of the system. The first one is guaranteed by the use of free licensing software tools and standard technology, and by defining that all printed information goes in legal size sheets of paper; a web browser as the front end satisfies the second one. In this way, neither, CVP or its beneficiaries have to incur in additional costs to implement or use CatArSis.

The software architecture of CatArSis consists of 7 components, 4 of them using extensively SVG: Geometric, Architectural models, Interface and visualization and Document generation. The development platform is Windows, Java 1.5, using SVG and Batik for graphic information and Postgres as DBMS.

The architectural and urban success of CatArSis can be measured regarding the objective population: Over 10.000 VIS projects could beneficiate each year, only in Bogotá. The whole process time, until starting of construction, will be reduced to 50%, and the related costs to 10%. For the city, it is expected a great improvement in its development, having a better ordered city, less informal building, lower risks and reduced management costs.

The technical success of the project is based on the choosing of SVG as primary format to represent and customize the architectural information of models, because it provides independence of commercial tools, usability of the system, and the possibility to edit the architectural models in order to satisfy legal requirements. One of the most interesting SVG issues solved was the preservation of the aspect ratio of architectural information, in order to preserve the original scale of plans.

CatArSis is in use now in Bogotá and its future concerns its dissemination, the production of new models and improvement of its functionality.