Rapid prototyping and computational design have taken hold of architectural design. While some architects design using a pencil and paper, others are utilizing the computing and calculating power of modern-day processors to generate hundreds, or even thousands, of iterations for design within a given set of parameters. With the understanding that this methodology aims to produce optimized results, the way in which this relates to preservation is questionable.
Parametric modeling programs, such as Grasshopper, provide a framework for architectural production--not design. A set of spatial parameters are established with a range and certain dependencies. What is produced is a digital model abiding by all of the rules established with the parameters. Because of the nature of the modeling program, parameters must take on a spatial reference and in that sense are limited to what can be modelled in three dimensions. The failure of this methodology in historic settings is the rift between the spatial and the intangible. How can some values be reduced to a spatial response?
A designer could make decisions regarding a set of parameters that exist in a historic building. Parameters for column spacing and floor heights could all be established because they are fundamentally spatial and three dimensional. The rift between the spatial and the intangible shows when examining how to acknowledge things such as social justice or historical events. How can topics such as those be captured spatially?
An appropriate response to intangible values on a site might be through the use of a particular material or controlling how light enters the building. Sometimes other senses must be engaged by a place in order to convey meaning that is not visual--not spatial. In this regard, I see the role of the designer as that of an interpreter, as somebody who can attempt to involve senses other than sight.
Parametric design and rapid prototyping have a place in the design field, but only to the extent that they may produce the spatial responses to an architectural problem in a historic setting. Beyond that, the designer may elect to employ metaphorical responses through texture, color, light, warmth, et cetera to promote ideas and heritage values that cannot be reduced to a parameter that is spatial. In short, the role of the designer is not obsolete within the realm of preservation.