Originating from Hungary in 1982, Graphisoft’s ArchiCAD is the most mature 3D Building Information Modelling solution on the market. With a very loyal installed base over Europe and America, the company regularly produces updates and add-ons. Martyn Day evaluates two of the latest enhancements.
While it may have taken decades for architects to get into 3D, the advantages of Building Information Modelling (BIM) have now instigated a move towards detailed virtual buildings instead of just drawing plans and elevations.
While the initial benefits of modelling in a BIM system are the automatic production of drawings and elevations, together with guaranteed co-ordination of edits across all documentation, there are other advantages. As a 3D model has to be created to get the drawings, it can also be used for creating photorealistic renderings, fly-throughs, sun studies and carbon footprint analysis. BIM is rapidly being seen as a prototyping environment for architectural and structural designs, and particularly for key eco-related criteria.
Graphisoft has long pushed the benefits of model analysis but has mainly worked with third party developers, such as Ecotect, to offer external applications. Unfortunately Ecotect was bought by rivals Autodesk, and these add-on applications also required the model to be exported outside of ArchiCAD, leading to a disconnect in the process. In response, Graphisoft has released EcoDesigner, an application that works inside ArchiCAD and gives architects a good indication of the environmental impact of any building under design.
EcoDesigner
While there are a number of carbon and energy-use analysis applications on the market, Graphisoft identified a niche area for an application that gives architects quick and simple feedback on the quality of their design. Sustainability is all about making the right choices early in the initial design phases and architects have a major influence on a building’s energy performance.
EcoDesigner helps architects compare energy consumption, monthly energy balances and other key eco-indicators to improve the building creation process and keep the architect aware of the impact of design changes.
EcoDesigner is an add-on for ArchiCAD version 12 and ultimately provides a ‘one-click’ analysis tool. However, to get to that one-click, a number of steps have to be followed. The first stage involves placing the model in context, setting the city, the ‘North’, the wind protection, type of surroundings, facade shadings and assign usage (residential, education, hospital etc). These are all used to derive the temperature and heat gain profile of the building.
The next stage is to allocate materials to the main structural elements. EcoDesigner does a good job of automatically recognising the key structural elements, but these need to be allocated materials such as plaster, concrete or wood, together with the type of surface material. The software automatically works out the areas, thickness and U-values. The U-value is a figure that denotes the heat transfer capability of a material or assembly of materials. Every structural component in a building has a U-value and is used in the energy calculation. There is a massive database of materials to choose from with thermal conductivity, density and heat capacities. If materials are not in the library it is easy for users to add their own custom materials, also thicknesses and values can be edited too. The same process is repeated for all the openings. Obviously the more complicated the building the more time will be spent in prepping the design for final analysis.
The final information to be entered covers the mechanical electrical plant (MEP) systems and energy systems contained within the building. This covers the hot water generation, cooling system types, ventilation type, any energy recovery systems, efficiency levels, heat pumps, solar panels and the unit costs. Once complete the result is finally one click away.
After some number crunching EcoDesigner produces an XML output report (which can be saved as a PDF) with all the key facts and figures on the design performance. The Energy Balance Report includes an array of useful information: floor area, ventilated volume, heat transfer for key structural components and the average U-value for the building. The Energy consumption is displayed per month in a bar chart showing energy emitted and energy supplied, together with the breakdown of sources. Then there is an all-important CO2 emission figure in Kg CO2/year.
On a decent size model, there is a fair amount of prep work involved in getting to this result. However, once a design is defined, making small changes usually means that EcoDesigner can quickly spit out revised evaluations, enabling comparisons and fast design optimisation.
Virtual Building Explorer
When time and effort has been placed into creating a 3D model of a building, it seems a shame to have to send only 2D drawings of still rendered images to clients, contractors or structural engineers. Graphisoft’s solution to this is Virtual Building Explorer (VBE), which is an application for generating self-extracting ‘virtual worlds’ from ArchiCAD models. This enables other teams to navigate and explore designs without having to have copies of ArchiCAD, using ‘games like’ friendly controls. Each environment has ‘gravity’, layer control, fly-mode, egress recognition and pre-saved walkthroughs. Storing walkthroughs and multiple viewpoints in the gallery are great ways to guide recipients as to specific features of the design.
While navigation alone is a useful capability, VBE extracts and offers access to building information such as surface finishes, volumes, sizes and quantities. Exact measurements can be made at any point during a walk through with access to element information and layer control for more advanced users.
There are multiple viewing modes — perspective or parallel, line-drawing, shaded cartoon-style, fast OpenGL with shadows, materials and texture maps, or high-end Global Illumination radiosity rendering with controls for camera height and view cone, sun altitude and azimuth, brightness and transparency. With 3D it is even possible to use the stereo viewing capability using the special red/cyan glasses that come in each software box.
Using VBE is very straightforward. Once installed an additional function is added to the ArchiCAD menu to ‘Export for Virtual Building Explorer’, this will convert the model into a VBE model, including materials, geometry and surfaces. After launching VBE there are lots of style settings that can be adjusted to create the viewing experience that is intended. At this stage pre-defined walkthroughs and set viewpoints can be created for inclusion. Then simply save out the model as a self-contained, self-extracting file. This file can then be distributed under a free license. The only limitation being that VBE files can only be opened in the Windows operating system. An OSX/Mac version is in development.
Conclusion
One of the main problems associated with a move to BIM is the extra effort required to build a detailed 3D model. The real story of EcoDesigner and Virtual Building Explorer is that the creation of the virtual building model is only the start of the design process. The more uses there are for the model the greater the return on the investment in its creation.
The ability to send complete model environments to customers or other project members to explore designs is obviously of massive benefit. The fact that there is no need for ArchiCAD, an application or in fact any CAD knowledge is an obvious boon in enabling collaboration. This is equally applicable from the earliest design stages to final construction and fit-out. Virtual Building Explorer is a brilliant addition.
EcoDesigner is an important application for ArchiCAD customers and is to some extent a return fire at Autodesk acquiring Ecotect. Instead of producing a carbon copy of Ecotect, Graphisoft has taken the opportunity to build code that works inside ArchiCAD, requiring no translation, with a feature set that requires the most basic information. EcoDesigner is not intended to be a super-accurate analysis tool but more of a tool to give feedback on the impact of key design decisions, such as materials, glazing and ventilation decisions. It performs this function admirably and should become an essential add-on for ArchiCAD customers and great value for those on subscription.
