2D CAD and BIM have both been sold on their benefits to the detailed documentation stage of a project. Ideation and conceptual design, at best, has fallen to simple mass modelling. Will the latest batch of tools change this?

Pen and paper, pencil sketches, cardboard, foam, scrunched up paper, lego, clay; whichever way you do it, it is still a highly analogue, iterative, exploration process. While the end design will need to be detailed in some form of Computer Aided Design (CAD) system, the limitations and explicit nature of CAD makes it far from useful at the formative stages of the design process.

Physical, real-world form finding and sketching will never disappear but many software firms are attempting to assist the ideation needs of architects through a variety of approaches.

Autodesk Dynamo is a visual scripting (plug and play) tool for Vasari and Revit enabling points to be placed, manipulated and geometry created based on variables and equations.

To some degree, any significant move towards digital concept design is also going to be a generational issue, with younger minds more willing to experiment with the latest technology.

I do not expect an architect like Frank Gehry will ever migrate from his pen and paper models but new recruits and future signature architects may well adopt a computer-aided approach.

Mightier than the pen?

CAD software developers are looking to digitise the pen. Just as CAD replaced the drawing board, could the latest touch interfaces and styli replicate the drawing process?

Companies like Wacom led the charge with its pen tablets, pen displays and styli for mobile tablets. Products like the Cintiq moves the computer’s monitor to a reclined drafting position, adds touch sensitivity and provides a powerful digital sketching tool when combined with industrial design sketching software and products like Alias and SketchBook Pro from Autodesk. These displays are very common in automotive and product design.

However, the pen displays are not cheap and find themselves now competing with the new smaller tablets, such as the iPad.

There are many, many 2D sketching apps available. Autodesk has SketchBook Pro and SketchBook Ink, Adobe has Photoshop Touch. There is a great app called Paper and Wacom’s Bamboo Stylus (I think it is the best one out there) comes with its own drawing application. Judging from some of the work done by customers, the quality of output that can be created rivals anything I have seen on paper, it is just a question of adapting to the tool set and having the time to experiment.

The advantage of having a digital sketch means it is easier to display and share wherever you are and possibly use as a start point for massing. The more advanced (expensive) PC-based sketching systems enable freeform sketching and will take these to create Class A surfaced models, ready for generating car bodies and beautifully sculpted forms.

Simple 3D modelling

While there are a number of established conceptual design tools, the new ‘point of entry’ for creating masses is Autodesk’s FormIt, which is both an iPad/tablet application, as well as a full ‘in-browser’, free modelling tool. The software both delights and frustrates but I have seen some amazingly detailed models created in it.

Concept design in practice

At this year’s Council on Tall Buildings and Habitat, held in London, Martyn Day caught up with Robin Partington of Robin Partington Architects (RPA) and formerly of Foster&Partners, where he was most well know for his work on London’s Swiss Re building, aka the ‘Gherkin’. I asked Robin about his practice’s approach to the conceptual stage of design

“We choose our tools on a project by project basis. Yes we use Rhino and others but the backbone of our company is Bentley Systems’ tools. We don’t tend to use SketchUp that much, as we tend to want to give meaning to the designs of our buildings at a pretty early stage.

“What’s changed in the last two or three years is the way we are using CAD. Instead of the 3D team playing catch up with the design team using pencils or scalpels, we are now using 3D right up front, defining the parameters for the building, defining the logic.

“It’s not exclusive, we still sketch, model with cut foam but we now run in parallel as each one has a strength and appropriate at a particular time in the concept phase, each feeding off each other. However, none of the manual techniques capture the logic that’s going to drive the process and feed into our backbone and refining process.

“In the past we used to push the design really hard with ‘scribbles’, foamboard and sketches an the someone would ‘CAD it up’. That isn’t helpful, that’s a recording process.

“The current range of projects we use all tools parallel but the next generation will lead with digital tools. We are working on a new 42 storey 200 apartment residential building with a complex shape, there is no repetition floor on floor. Every apartment on every floor is different and the amount of design per square foot is much higher than an office building. How do you manage such a complex design?

“Before we go into detailed design before we let the architects loose with pens and foamboard, we are sorting out the rules, defining the schema in the computer that will allow us to control the process.”

Satellite maps can be pulled in for modelling ‘in-situ’ and sun studies can be carried out. These models can be taken through to Autodesk’s analysis tool Vasari or into full Revit. As the software is ‘cloud-enabled’, whatever you design can be accessed from anywhere. While it remains a work in progress, Autodesk’s development team has done some great work here.

Trimble SketchUp Make and Pro, as they are now called (see pages 14 and 15), have been doing the design community a great service for over a decade by providing a free and easy to use 3D modelling tool. Many architects have cut their teeth on this software to generate both simple and complex designs, to examine volumes and create renders.

As the product has progressed, it is now possible to download powerful applications to assist in quick creation of walls, doors, windows, floors and roves, as well as run lightweight environmental analysis. The Pro version adds a layout tool to produce detail drawings, sections and elevations. Although SketchUp models can be exported and used in BIM solutions to define the production geometry.

For all its good features, SketchUp is geometrically limited and to get anything non-rectilinear requires some thought.

A low cost tool that has made some impact for advanced users is bonsai3D from AutoDesSys (the folks behind FormZ). Bonzai3D is specifically aimed at sketching and conceptual modelling with a powerful NURBS geometry engine. It has lots of sexy capabilities like high-end rendering, the ability to unfold geometry, animation, 3D printer support, contour and terrain tools, documentation and fabrication links.

Probably the king of the low-cost modellers is McNeel Rhino. Its industrial strength engine plus extreme popularity has made the product a bit of an industry enigma. With a powerful API, there is a huge third-party developer community and the product is used in everything from conceptual design to fully defining highly complex buildings that you may have seen at last year’s London Olympics. Rhino is pretty much the de facto standard with young designers and heavily used in signature architects practices of the likes of Zaha Hadid.

Computation and modelling

Talking of Rhino, there is a free add-on called Grasshopper, which offers a visual scripting interface to drive the creation and definition of geometry. This was first done by Robert Aish at Bentley with its Generative Components application, which ran on top of MicroStation.

Here the designer can create their own tools through programming. Would you like a roof that has beams like a sunflower Fibonacci series? Or a structure that automatically adapts to edits around the edges? Using these scripting tools its possible to use the power of the computer to find the best solution through computer-aided generation.

Again many of the leading architects have special modelling teams that assist in developing scripts and programs to allow the designers to experiment with complex geometry. However the arrival of plug and play visual interfaces has brought this powerful capability down to us non-programming mere-mortals.

This trend towards computation design has not been lost on Autodesk. It hired Dr Aish away from Bentley and now has DesignScript, a new parametric language for AutoCAD. It has also just released Dynamo, which is a visual scripting (plug and play) tool for Vasari and Revit, looking very similar to grasshopper for Rhino, enabling points to be placed, manipulated and geometry created based on variables and equations. This could be used to drive underlying geometry, such as a roof shape in Vasari and, with iterative changes and analysis, to find the optimal shape for solar radiation or wind load.

It is at this point that we can look back at the suite of conceptual design tools and see how merely replicating the sketching function really is such a small part of what computers could possibly offer the form-finding process.

Experimental design of folded and woven roof patterns completed in Grasshopper by Arthur Mamou-Mani, Jawaher A Al-Abdulla and Simply Rhino.

The earlier in the process that inefficiencies and problems can be identified, the better the quality and performance of the deliverable.

Scripted form finding, optimisation and visual feedback of performance are incredibly powerful tools to have. A number of leading-edge architects are already benefiting from generative tools throughout the entire process.

Imagine being told by planner that a complex curved tower needs to be 50 metres lower and the amount of work that would involve in 2D or BIM in working out the pannelisation alone. Using parametric scripting tools some architectural practices can literally grab the top of a complex curved building and move it down, the software automating many of the necessary changes in the rest of the building.

As projects grow in complexity, computer-based conceptual tools such as Generative Components are already helping architects such as Robin Partington Architects (RPA) tackle daunting design tasks and connecting the creation tools to the documentation ‘backbone’. While many practices will not face the challenges of this extreme form of architecture, the process adopted by RPA is one that is being replicated in many design firms.


CAD and BIM systems are not very good at dealing with imprecise abstractions. Sketching is always going to be a worthy skill to have and there will be many mediums through which to express more artistic abilities — and paper does not run out of battery power!

The challenge is to clearly define a complete internal process of taking concept through to delivery of detailed drawings identifying the best technology fit, offering maximum benefit to each stage. For many it starts with a pencil and always will, but beyond sketching, before detailed design there are now a number of powerful tools which provide clear early feedback as to how well a design meets the brief or identify a number of viable solutions to be considered. Inefficiencies discovered early on can be designed out, saving money on HVAC and other operational costs.

Leading architects are already considering how a complete digital process could benefit their practices, from the basics, such as being able to capture and store concept ideas, to driving explicit model generation and regeneration through an iterative process.

There are a range of low-cost tools that can be adopted by any architectural practice to go digital earlier and use the computing power that is already on their desktops to increase the confidence that early concepts will meet, if not surpass client briefs.

Conceptual design: alternatives

Autodesk Dynamo and Vasari

Vasari (pictured) is a conceptual massing design tool for creating building concepts. Offering integrated analysis for energy and carbon to help optimise design intent, models can be seamlessly passed on to Autodesk Revit. Vasari Beta 3 is now live, with improvements that went in to Revit 2014, use on Windows 8, and a license that is good till May 2014, according to Autodesk.

Dynamo is Autodesk’s free visual scripting tool for Vasari and Revit which is similar to McNeel Grasshopper.

Points and geometry can be manipulated through a plug and play interface to assist in generative complex form finding and targeting the most efficient design to meet the customer’s brief.

McNeel Rhinoceros and Grasshopper

Rhino is a de facto standard in advanced architectural practices. The NURBS based modeller is popular with graduates and supports a sizable ecosystem of plug-in products pushing Rhino’s capabilities to match most higher-priced CAD systems.

Grasshopper (pictured) is a free visual front-end to Rhino for generative scripts to create and manipulate complex geometry. Programs are created by dragging components onto a canvas and connecting them with ‘wires’ to create generative algorithms, which make and manipulate Rhino geometry. With Rhino’s popularity, there are a lot of Grasshopper users and many modern buildings have benefitted from its use.

Autodesk SketchBook Pro and Ink

Tablet or PC-based, Autodesk SketchBook Pro (pictured) is a sketch, paint and drawing application. Made for professional designers, artists and illustrators, SketchBook Pro is specially optimised to work with pen tablets such as Wacom Bamboo, Intuos, and Cintq products, to deliver an authentic drawing experience.

It has more than 100 illustration tools, custom colours, and do-it-yourself brushes.

SketchBook Ink is a resolution-independent pen and ink drawing application. While not as powerful as SketchBook Pro, the software outputs high resolution images directly from a tablet computer. The software is only available in the iTunes store.

AutoDesSys bonzai3D

Bonzai3d comes from the developers of FormZ. It is a 3D modelling application aimed at delivering conceptual design and sketching.

According to AutoDesSys, bonzai3d offers a powerful geometry engine over products like SketchUp and creates models that can be used for construction drawings, photorealistic rendering, and fabrication.

The lastest version, bonzai3d 3.0 adds 80 new features including 14 new tools that add functionality for fabrication, 3D printing, NURBS modelling, shape editing, texture mapping and component management.

A Sun Position palette has been added to make creating shadow and sun studies easier.

The website hosts a number of user forums to help crack that niggling issue, and includes tutorials by users and a Maxwell render plugin.

Bentley Systems AECOsim with GC

AECOsim is Bentley’s professional multi-disciplined BIM offering based on the company’s core platform, MicroStation. Generative Components (GC) was the first generative scripting tool for conceptual design and works on plain geometry or BIM components.

It is possible to work through many ‘what if’ scenarios by directly manipulating geometry while capturing relationships among building elements. Generative Components is already enabling leading architects and engineers around the world including HOK , Arup, Foster+Partners, Grimshaw Architects, , Kohn Pedersen Fox, Morphosis, and many more.

Autodesk FormIt This cloud-based conceptual modeller points the way to what could become a powerful free massing tool to compete with the likes of SketchUp. autodeskformit.com.

Trimble SketchUp Make and Pro Trimble has reignited SketchUp within its Trimble Buildings strategy with its own ecosystem of vertical building applications and the Pro version bringing production quality drawing. sketchup.com