Form making

Designing the Royal Ontario Museum’s Michael Lee-Chin Crystal was a daunting task for many, many reasons. But two of the biggest were the tight budget (a reality known to most builders) and, surprisingly, something that is standard in most conventional designs: the very nature of two-dimensional drawings, which by themselves were inadequate for creating a blueprint for the extremely complex building.

A three-dimensional co-ordinate system was required to lay out different parts of the building and to create special key diagrams and multiple drawings of the same walls, explains Stephane Raymond, project architect of Studio Daniel Libeskind who, together with Toronto-based firm Bregman + Hamann Architects, formed the design team.

Raymond, who started working on the project in 2002, spent much of his time on site resolving these issues. To produce different drawings of the same walls, architectural elevations (wall elevations as though the viewer is standing perpendicular to the ground) and orthogonal elevations (elevations as though the viewer is standing at the same angle as the wall) were made. Some drawings were specific to construction while others helped bidding subcontractors determine accurate job costing.

A software program called Form-Z simplified conventional plans, sections and elevations. “The other main reason for using this software is that we, as an office, do not like to rely solely on digital models,” Raymond says.

Physical models were constructed from the digital models (and vice versa) to best understand the volumes within the Crystal. To create a physical model from a two-dimensional model, a print-out was glued to cardstock and cut, scored and folded along lines generated by Form-Z — a process much like origami. Models were created in as little as 30 minutes. “We could then choose to make changes to this physical model and feed the information back into the digital model,” Raymond recalls.

The formation of the structural design — the “diagrid” — came from the development of the geometry and the first faade ideas. The diagrid is a system for constructing large buildings from steel using a triangular structure with diagonal bracing. Theoretically, the diagrid design uses less steel and allows for multiple load paths. “To us, the architects, that meant we could have galleries free from interior columns but more importantly it meant we could move the steel around to suit our purposes,” Raymond says.

After establishing a semi-fixed geometry for the building, structural engineering consultant Halsall Associates Ltd. provided the architects with a starting point for the structure, which “we incorporated into our model in the form of centerlines,” explains Raymond.

In conventional designs, the structural system largely dictates the building form. For instance, faade elements are often set to the spacing of the structure, and internal openings such as doors are simply located where they fit best — away from structural elements such as columns. Not so at the ROM. “We wanted to be consistent on the inside with the language we had established on the faade, so the openings were of paramount importance to us,” Raymond says. “The structure would have to work around that as opposed to us working around the structure.”

To accomplish that, the design team removed diagonals in some areas of the building and adjusted node points (intersection points of multiple structural steel members) so parts of the triangular structure were irregular. This approach was also used in the placement of ductwork and other mechanical services.

Raymond says ductwork was digitally modeled so internal trusses could be modified to allow for the clear passage of all the ducts. The rainwater leaders were also modeled for routing, which was not always the most direct route because of the placement of windows. Sprinklers, too, were modeled to ensure adequate coverage of the floor area from locations that sometimes were on sloping walls and ceilings.

Equally important was creating two dimensional drawings from the models for the bidding process. While companies such as steel fabricator Walters Inc. from Hamilton, Ont., have the software to prepare a bid from models, most contractors required drawings.

For each floor plate drawing, three floor plan drawings were created. The principal, or “general reference drawing,” showed the finished top slab of each floor. Typical floor plates are comprised of two slabs 14 inches apart which create a plenum for the main air distribution, electrical, security and other infrastructure services.

The second floor drawing, called a “finished floor setting-out point drawing,” included all important points specified as coordinates in three-dimensional forms, with each corner of the slab marked as a coordinate. Like the first drawing it didn’t have dimensions because it was virtually impossible to create the dimensions of the ROM by conventional means.

The third plan drawing, or “lower slab setting out point drawing,” included duct openings into the plenum marked with three-dimensional co-ordinates using the perimeter concrete curb. The perimeter concrete curb was an important element in the design for its function in helping support the upper slab; acting as a continuous barrier to contain the plenum air; supporting the interior walls; being an integral part of the fire-supression system; and as a main support of the cantilevered floors at the windows.

“The perimeter curb is geometrically complex because in many areas it follows the slope of the exterior walls,” Raymond explains. Using a full-time surveyor, the construction manager, Markham, Ont.-based Vanbots Construction Corporation, did the layout of all the three-dimensional co-ordinates.

More challenging even than creating the design was keeping it within budget. To meet that end, the design team specified many standardized products and materials. But the ROM’s complex geometry didn’t always marry well with conventional products. The design team re-examined all aspects of construction — even mundane areas like fire control — to devise effective alterations. “In this way we were able to keep costs down, avoiding costly exercises like developing new products and all the required testing that that entails,” Raymond says.

For the first six months of the project in 2002, the design team worked in Berlin, at SDL’s head office (now in New York). The team was comprised mostly of SDL architects and two architects from B+H Architects who moved to Berlin to work on the project. “It was during that six-month time period that we resolved the basic geometrical issues,” Raymond says. The two offices were more fully integrated in Toronto in January 2003.

You might also like

Leave A Reply

Your email address will not be published.