Building Information Modelling (BIM) developers have mainly been concerned with providing tools to complete new build projects. In these challenging economic times of make do and mend, features for renovation and retrofit are the ‘new new’. By Martyn Day.
A walk through central London would indicate that there is still quite a bit of construction work going on. Pretty much from anywhere in the heart of the city, Renzo Piano’s Shard is visible as the core takes shape dominating the capital’s skyline. The reality is that these prestigious projects still have momentum but the normal bread and butter architectural projects have become a mix of new and renovation.
One of the first victims of the global economic downturn was the then Labour government’s ‘Schools of the future’ programme, killing 715 new schools, work for which many smaller practices were involved. The result of this change in policy is that there will have to be more renovation of existing building stock to meet the public’s needs, as well as meet stringent future energy efficiency targets.
I write this article on a day that sees the energy firms increase their winter prices by a whopping 19 percent for gas and 10 percent for electricity. Energy consumption will become a critical factor in the owning and operating of any building, and old, ‘inefficient’ buildings are clearly going to become liabilities. In Germany alone, the government wants to reduce energy consumption by 80 percent by 2050, which means that over 12 million homes will need to be updated.
Perhaps it is well timed that the latest version of Graphisoft’s BIM modeller, ArchiCAD 15 comes with a suite of new capabilities specifically targeted at improving the workflow of renovation and retrofit projects. This comes amid a general trend from Building Information Modelling (BIM) software developers to deal with as-built structures in a much more inclusive manner to meet the change in project mix of their customers. The renovation market in the UK is expected to be worth £46 billion in 2012. In 2009 you would have been hard pressed to find any serious renovation features in the popular BIM tools, now it’s deemed a competitive necessity.
While, as usual, there are a plethora of new features in ArchiCAD 15, with updates and enhancements, we have split this review into two; renovation this month and then the nuts and bolts general functions in the September / October edition of AEC Magazine.
So how can BIM best support renovation workflows? In Graphisoft’s view of the process, the first task is to capture the as-built conditions and this is usually done via a survey. This survey feeds into the BIM system and a model is produced. The next step is to indicate which parts of the building need to be demolished with some automation in identifying elements/breaking up existing elements and auto filling of holes, as well as some way of identifying new structure versus existing structure.
The system would be accurate to produce the correct quantity calculations for the new elements and as the majority of energy-saving retrofit jobs will include pipework, Mechanical, Electrical Plumbing (MEP) elements will be essential. New energy calculations will need to be run on the upgraded structure and then clearly handled in producing demolition and construction documentation.
Capturing the existing structure can be carried out in a number of ways. Traditional surveying may provide a set of drawings which need to be imported and then modelled up, which while easy isn’t probably the best use of time. There are a number of add-on products for ArchiCAD that can assist in the automation of digitally capturing this data (Orthograph, Flexijet and ArchiMap).
Graphisoft has not yet included support for point-cloud data, which is another emerging technology for a ‘Scan to BIM’ solution, but this can be integrated using other point-cloud specialist tools, such as PoinTools (www.pointools.com).
BIM models consist of elements. After a model of an as-built structure is completed, the next step is to indicate how the updated building will be configured. To enable this Graphisoft has added some new element-level renovation statuses for existing, new, and to-be-demolished structures (and includes a nice hammer icon), providing quick feedback on the status of any element through a renovation project.
From the new renovation palette, users access the element selection tool, renovation filters (to display the project at various stages). Clicking through elements in the model will provide instant feedback as to the renovation status (existing, new, to-be-demolished).
Simply click on elements and select demolish. Then create new walls, doors, windows and other elements that will replace the demolished sections, while remembering to tag the new geometry as ‘new’ in the renovation palette. As the new elements are tagged, ArchiCAD can work out exact quantities of materials.
To get a clearer view of the status, toggle the renovate filter and ‘existing’ versus ‘new’ and ‘to-be- demolished’ are clearly highlighted in different colours. The filters can be user-defined to hide dimensions, have solid fills, remove confusing intersections and hide zones of areas that are eliminated.
In practice this is exceptionally easy and made very clear with the colour filters. The added benefit here is that all the various statuses are kept in a single file, removing duplication of files and effort.
With increasing demands on the engineered components within buildings, Graphisoft has enhanced the ability for the architectural version of ArchiCAD to import MEP IFCs and integrate MEP elements within the system.
There is a specific version of ArchiCAD for MEP called MEP modeller for building services engineers. Graphisoft has even written plug-ins for AutoCAD MEP and Revit MEP to ease data translation straight out of Autodesk’s popular products into ArchiCAD.
With version 15, architects can visualise and fully understand the 3D MEP systems created by engineering teams before demolition plans are formed. ArchiCAD can also perform clash detection with a single click, finding and highlighting clashes.
ArchiCAD has its very own energy analysis module called EcoDesigner. It performs dynamic energy evaluation throughout the design process, providing: building envelope performance, energy consumption, monthly energy balance and a building’s carbon footprint.
Ideally any energy retrofit will be tested throughout the design process to optimise the design. Material properties can be allocated to construction or entered directly through ‘U’ value.
New in this release, the support for ‘passive’ building performance, more cooling and ventilation options for MEP elements, solar collectors, the ability to calculate on multiple buildings, export to Excel and an export to Strusoft’s high-end VIP energy solver.
It is easy to document the existing, demolition and planned stages of the project using the filtered views. By creating layout folders from these views, the views are automatically placed in drawings which can then be published. By plotting PDF for instance, the three plans can be saved together and quickly viewed, with the different filters proving colour feedback as to what is happening in the three key stages.
ArchiCAD comes with pre-configured renovation plan types together with a selection of popular European drafting styles that follow local CAD standards and documentation conventions.
In this release Graphisoft has not just added some renovation capabilities to ArchiCAD but has delivered a comprehensive vision of workflow for documenting and modelling what can be a very complex process. It’s easy to use, intuitive and flexible for those that want to generate their own standards.
I would like to see support for point-cloud at some point as laser scanning can offer considerable benefits in capturing as-built conditions in 3D. The technology to intelligently convert this data in BIM components has not been solved yet but there will come a time when laser- based surveys will replace the traditional surveying methodology of pen and paper or disto and data logger.
In the September/October edition of AEC Magazine we continue our journey through ArchiCAD 15, with a focus on performance, modelling and documentation improvements.