Designing low energy buildings: application of a parametric tool and case studies

Still the traditional design approach, and even more the Integrated Design Process, need an effective and efficient design methodology and smart, useful and fast design support tools, in order to fulfil the requirements of low energy buildings besides all other issues included in the “building design”: aesthetic, functionality, budget limit, customer requirements. How can the design team being well supported in the choice of the final set of solutions? Which operative and useful approach can become a common design method in order to efficiently achieve the compulsory low energy standards? Based on PHPP (Passive House Planning Package) an excel macro has been developed in order to perform parametric analyses on many design input variables. This parametric approach is the core of a wider design methodology including also the use of guidelines for the definition of the design concept, the definition of a base case in PHPP relying on the already fixed, the postprocessing and the repetition of the parametric analysis at different design steps, each time with less free variables. Two office buildings under design process have been chosen as case studies for testing and assessing the whole methodology. The parametric tool – through fast, numeric, quantitative and parametric results – has proven to be a effective design support tool.