HDM, the Heritage Development Model is a scientific model which deals with strategic and economical dilemmas in middle sized and large heritage conservation projects. It is a structured relational database for areas, sites and objects, differentiated by typology, size, quality and ambition.
Based on a detailed administration of the existing situation and of the new development scenarios, the database returns an:

– relevance index of the objects within the modelled development scenario,
– the current demand for investment,
– the expected yearly maintenance costs,
– the impulse period (the period after which new investment is required) and
– a revenue potential.

By applying the model consequently, you can direct proper investments and have the control over the revenue. The HDM results can be used in quality enhancement, clever sustainability and broad preservation of cultural heritage. The calculated results can justify future actions and verify the results of these actions. The method can be used as an argument generator in policymaking process. It is the first input for business case scenarios. It can be helpful in planning of future functions in the existing real estate. It can be an economic reference and administrative base for the future site management.
Generally speaking and for better understanding the HDM could be a computer game. You start modelling the situation as it is and by testing various development scenario’s you will get a sense of the actual potential of your heritage site. The most relevant strategy for development will step by step become clearer.
The HDM could be used to validate viability of different sizes of the projects, from one object development through to the large area development projects.
There is always a danger that by developing the commercial utilization will take over the monumental quality of heritage sites and objects. We should know in advance what are the possibilities. We cannot or should not earn money on all, but we should do it wisely on some.
Therefore, HDM helps not only to estimate possible investments and income, but also to define a limit of development. The development is seen as positive if able to fund the conservation of the site overall. Overdevelopment is not appropriate and is harmful to the monumental value.