Communicating and solving design changes with technology

Going back to planning

To enable the building to meet current building regulations, airc.design needed to make some amendments to the original design while retaining the same number and mix of dwellings.

For example, the proposed lifts and lift shafts had to be increased in size to allow for Part M-compliant lifts. This had a knock-on effect on the footprint of the building, which had to be increased, and on the internal layout of the flats, which had to be fully re-designed and reorganised.

Another challenge was the biophilic aspect of the planning stage consented design that included fixed-planters on the elevations. Following the tragedy of Grenfell Tower, building regulations exclude all combustible materials on the elevations of residential buildings over 18m tall, so the planters had to be removed from the design.

However, the planning officers were very keen to retain the biophilic element. airc.design was able to address this with proposals for an enhanced green roof.

“With the help of Archicad, we were able to show and explain the reasons for our proposed amendments to the design immediately, which helped to bring the client, contractor, design team and council with us,” says Pierre Saunal, studio design lead and co-founder of airc.design.

A change of aesthetic

With the biophilic planters removed from the façade design, airc.design needed to address the building’s aesthetic to soften its appearance as requested by Ealing Council.

“One of the main elements of the proposed re-design was the cladding on the tall element of the development,” explains Saunal. “Initially monochrome, we decided to explore a different approach.

“The new façade design is a modern twist on the elevations of existing houses located in the conservation area south of the site and uses four colours extracted from the growth cycle of an English oak tree.

“A shade of brown and three shades of green ceramic tiles are combined to create a pixelated pattern, going from brown through to darker and darker greens in a V-shape to represent the shape of a tree and the fact that the proposal is the first of its kind in the growth of the local area.”

Jigsaw of cladding panels

There was no budget available for a bespoke façade, so airc.design needed to work with standard-sized tiles and use them in an innovative way to achieve the desired effect.

Jaime Ingram, BIM leader and co-founder of sister business airc.digital, takes up the story: “We modelled all 4,955 cladding panels in Archicad. Every one was modelled individually, with the help of bespoke in-house GDL tools, which airc.digital developed for the project.

“During this stage, we worked very closely with the tile manufacturer. Previously the manufacturer had been used to working in 2D, but our design involved a number of complicated junctions, so we persuaded them to work in 3D for this project.

“All codes came from the manufacturer, detailing the standard sizes of the cladding tiles, but we specified which colour should be used for each individual tile. This level of specificity was only possible because it was fully modelled in Archicad.”

Communicating design amendments

airc.design and airc.digital worked in Archicad throughout the project, helping the team to perfect the design, manage a complicated workflow and communicate with multiple stakeholders as Saunal and Ingram explain: “Archicad and BIMx were essential to show how this new design would work. We also used BIMx for visualisation, but without the help of Archicad, it wouldn’t have been possible to convince the client, the contractor, the planning consultant and the council of our proposed amendments.

“One feature within Archicad that was particularly useful was the graphical overrides, which enabled us to show the planners how different treatments would affect the look of the building.

“In addition, when showing the 3D model in Archicad, we could make the changes on the go during the meetings. This made it easy for the project’s stakeholders to see what we were proposing, and also improved their confidence by having the changes made immediately.

“Moreover, we needed to be very organised to manage the workflow. There were a few critical moments when we were working with multiple concurrent changes, but Archicad’s workflow helped us to manage that.”

A collaborative effort

airc.digital coordinated the project through the exchange of IFC models and BCF clash reports. Each discipline on the project used different software: airc.design designed the buildings using Archicad; structural engineer Fairhurst and M&E consultant Consolux and the façade cladding manufacturer worked in Revit; while Guarda Landscape used Vectorworks and SketchUp.

Meanwhile, the contractor Antvic, the developer Yellow Brick Capital and the property agents used a combination of the IFC models alongside the BIMx models and drawing sets produced by airc.design and BIMcollab visualisations produced by airc.digital.

“It was essential that the models were shared correctly throughout the project as each element affected another. For example, the downwater pipes in the façade framing needed to be in very specific positions. The position of the panels drives the position of the framing and everything is interconnected,” says Ingram

Demonstrating the value of BIM

Expected to complete in winter 2022, the development is an example of a collective and collaborative effort between all members of the project team. The openBIM philosophy of Archicad has been instrumental in enabling the coordination of the designs amongst all stakeholders.

“We’ve had great feedback from the client, the council and the consultants,” says Ingram. “With Archicad, we’ve been able to navigate the project quickly and efficiently. They were very impressed that we could make many of the changes straight away.

“Before this project, the contractor was working in 2D CAD. However, they have been convinced to start the change towards a BIM workflow and now open the model using BIMCollab. They’re now committed to working towards a common data environment and investing in new software and training.

“Moreover, the contractor has seen the huge benefits of being able to work in this way and as a result, has requested to work with airc.design and airc.digital on future projects.”

Saunal and Ingram will be presenting on 18 May at Digital Construction Week.

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