subject: Green Buildings With Bim Part 2: From Concept To Detailed Design [print this page] It is much more difficult to create an optimal environment within a building when it has already been designed, compared to working to specific goals from the planning phase. This can be expressed in fewer words: You can put lipstick on a pig . but it's still a pig'! In terms of green buildings, this means that systems like grey water tanks, solar panels, recycled office furniture and low energy appliances are the lipstick. If the building was not well-designed to take advantage of natural sunlight and ventilation, to be able to catch its own rainwater and provide it's own soundproofing and if it constantly requires heating and cooling to maintain a comfortable temperature it is a pig. Today we are looking at using building information modelling in the conceptualisation and detailed design phases of a construction project to ensure you don't end up with a lipsticked pig.
Green building design principles
The following are principles of green building design that, by using building information modelling facilitate:
Designing away unnecessary spaces
Designing for climate
Analysing the durability and longevity of a design
Use recycled, or recyclable, material where possible and practical
Conceptualization phase
At the conceptualisation phase, building information modelling makes it possible for architects and structural engineering teams to collaboratively analyse the impact of sun and shade in the environment on the building; to analyse and design solutions for stormwater, and to use geospatial buffering to counter the impact of nature on the building itself. Note that the computerized nature of BIM means that the information can be shared quickly and easily, in a paperless way that is in itself, green.
The materials conceptualisation is also assisted by this construction software. It allows designers to see how the thermal and mass properties of preferred materials will function in the environment of the completed building, and whether they live up to required standards. The impact of recycled materials in the construction can easily be assessed.
Detailed design phase
The detailed design phase of a green building project has several key planning areas where BIM is useful:
Lighting design
Air quality assurance
Duct and pipe sizing
Water supply planning
Building information modeling will impact lighting design decisions by providing a clear picture of how different areas will be lit during the day and eliminating or reducing lighting banks where they are less necessary. Air flow through the building can be predicted quite well, and the building information modeling system can help maximise the use of natural ventilation to reduce HVAC dependence.
Duct and pipe sizing is critical for ensuring HVAC efficiency, and BIM helps plan this as well as the positioning and type of water supply to the building. If greywater systems are going to be used, the piping may need to be made of different materials, or sized differently.
