CPD: ARBOLEDA - an Open BIM project
Modo Forma’s apartment development in Santo Domingo benefited from the clear workflows and building analysis of Vectorworks Architect software
This CPD, sponsored by Nemetschek Vectorworks aims to demonstrate, through the eyes of an architect-led team, the execution of a successful open BIM workflow for a proof of concept project using Vectorworks Architect.
Consultant team members for the project ranged from the owner to the energy consultant, to the MEP engineer to the BIM manager and coordinator. The proof of concept project was inspired by the Arboleda Building in Santo Domingo, in the Dominican Republic. The architect was Rubeno Nantes Fontana and his firm Modo Forma.
The Arboleda Building was completed in 2008 and is a multi-family, multi-storey urban infill residential project. It was executed using a small BIM approach utilising Vectorworks Architect. Watch a film of this.
Part 1: Introduction
Most firms today take a ‘small BIM’ approach, using models for architectural purposes and paper communication between consultants. Building Smart International and several software vendors therefore formed the Open BIM programme to collaborate workflows and reduce coordination errors, while allowing consultants to use their preferred software. This relies on IFC file formats, supported by over 95 vendors and developers and 145 BIM applications. BIM involves more work at a project’s front end than CAD.
For this proof-of-concept project we used iterative verification and coordination to bridge concept and feasibility phases; now no longer delineated. Instead,there is a loop of creating, validating and sharing with other consultants. A workflow diagram that coordinates tasks and building information models reinforces this.
Part 2: Initial concept
A site diagram was created to look at opportunities, including circulation and open space. Then GIS data was imported into Architect as shape files, simplified to display only primary contours and existing adjacent building footprints pad which were filled so they could be easily identified and extruded later.
Analytical tools were used to assess water flow and drainage. Detailed site planning, building massing and cut and fill studies followed. The design began with a concept sketch.
Major programmatic elements were developed through analogue sketches to communicate spatial relationships. The concept sketch was imported into Architect as an image file, then traced and extruded, and the massing model exported to Google Earth for contextual viewing. The Architect model was then used to explore massing, programming and net and gross areas.
Part 3: Concept development
Apartment plans were developed using bubble diagrams, an adjacency matrix and a stacking diagram. An extruded diagram was created to visualise spaces in a typical apartment and a standard layout emerged. The concept model was assembled, to look at different views. Vectorworks SimTread software was used to analyse the egress from apartments and produce a layout animation. The building model was then viewed in the context of the site model. A solar animation was produced using the heliodon tool.
Renderworks was used for external and internal renderings and furniture layout. Vectorworks Cloud Services and Nomad were used for remote collaboration and to quickly generate renderings. The architect used the AR-works plug-in to explore the overall design and the CadFaster plug-in was used by the project team to review problems remotely.
Part 4: BIM model setup
This was critical in the move from concept to design intent, which relies on an accurate, complete BIM model. The model was set up using storeys within Architect, comprising the TOS, ceiling soffit and TOS above. Layers were limited to these components, with other elements allocated classes. This was hugely beneficial when the model was exchanged within the team. Viewpoints were established to determine final output drawings.
The completed unit exclusively comprised Architect-native BIM objects, associated with data which could be shared with the team. Accurate layer mapping was essential. The model was now ready for validation and clash detection, using Solibri Model Checker as the bridge between team members via IFC. Flaws, including redundant column locations and clashes were repaired before it was shared with the team.
Part 5: Energy analysis
IES and IES VE-Pro were used for energy analysis and modelling and exchanges were made through IFC. Spaces were simplified, so one space accounted for the whole apartment.
Solibri questioned component information and validated the model and spaces. IES VE-Pro analysed and documented solar exposure and shading, using orientation, heating and cooling loads for the building and also wind loads for height and orientation. IES provided additional solar gain information and rendering of luminosity.
Data received from IES exchanges provided a base map for luminosity studies of apartments. The two studies below are differentiated by the way they account for lighting levels. The one on the left uses a colour index, while the one on the right uses numerical scoring. Obviously, lighting levels are highest near openings.
Part 6: Structural collaboration
Nemetschek Scia software was used for structural collaboration. Scia has a joint commitment to open BIM and can read IFC files. A structure-only model with essential elements such as beams, slabs and columns was prepared in Architect, then developed for analytical modelling in Scia, through conversion, clean-up and alignment, producing a finite elemental model with colour-designated materials and member cross-sections.
The lateral system comprised a concrete core with a moment frame offset from the centre of mass, causing torsional irregularity. Coupling beams greatly reduced shear. The finished model was shared with the architect using IFC. The engineer composed documentation for structural sheets using Architect. A schematic sheet was created from Scia information containing section and plan views, analysis and a rough bill of materials.
Part 7: MEP collaboration
DDS-CAD MEP software was used for its strength in dealing with multiple engineering disciplines and direct IFC exchanges. This allows the architectural and MEP teams to communicate through a shared platform. Preliminary DDS-CAD mechanical systems plan view layouts were seen from perspective angle and plumbing was laid out to check for clashes in Solibri. These were then plugged into the architectural model to identify other conflicts.
The mechanical system had clashes, including ductwork colliding with walls and embedded in slabs and between structural beams. There were also architectural problems involving mechanical runs within floor plates and ceilings. The process of laying out, viewing and revising produced a refined mechanical layout. At this stage, more traditional rectangular profiles were adopted for plenums.
Part 8: Material take-offs/project management
Material take-offs can be completed at the final stage within Architect. These allow you to quickly schedule and understand component quantities relative to net and gross areas. Space objects allow you to calculate entire areas. Material take-offs can also be completed, assessing the building for entire areas as space objects, either as the whole model or single floors. For apartments, components can be colour coded for quantification.
Synchro construction management software was used for its inherent strengths in working with BIM model integration via IFC, allowing for sophisticated scheduling, visualisation and graphic representation. When IFC files are imported into Synchro, members are assigned time conditions using key frames, allowing for accurate scheduling and understanding when pieces are complete.