BIM + the Building Envelope

By Jeff Yoders on December 23, 2010

Building envelope design is a specialized area of architectural and engineering practice that draws from all aspects of building science and indoor climate control. This includes structural integrity, moisture control, temperature/thermal control, and control of air pressure boundaries to create a continuous barrier between a building’s interior and the outside elements.

A building’s envelope is a complicated system of engineered and non-engineered components that all need to work together and be installed and constructed by a diverse team of construction professionals including glaziers, steel fabricators, waterproofing contractors, roofing installers, masonry contractors, and many others.

“Your team makeup is always diverse,” said Will Ikerd, Principle at Ikerd Consulting. and vice chair of the AGC BIM Forum’s designers’ sub-forum. “The vocabulary of envelope material is diverse and not always as well quantified as material in other industries such as structural steel.”

That’s why the Winter BIM Forum, entitled “BIM and Building Enclosures: Pushing the Envelope on Performance,” February 10 and 11th at the Hard Rock Hotel in San Diego, Calif., will focus on how BIM can help mitigate the risks and meet the challenges posed by today’s complicated building envelopes.

The risks

Building envelopes are one of the most expensive and litigious aspects of building construction and stand to gain the most from significant improvement in building design and construction.

“If we’re talking about engineered systems, then you have a number of issues that arise that don’t normally arise in stick construction or typical concrete or masonry wall systems,” said Patrick O’Connor,  a partner at Minneapolis law firm Faegre & Benson who specializes in construction law and chair of the  BIM Forum’s legal sub-forum.  “If it’s engineered by a third party, to what extent can the designer of record rely on the engineer or manufacturer? These systems can be very complex.”

O’Connor said the complexity of a building enclosure can be mitigated, in most instances, by using a 3D model to convey design intent.

“The responsibilities are usually not different than any construction project, the means and methods still go to the contractor and design team must still approve the shop drawings,” O’Connor said. “Generally the communication breaks down along the lines of does the designer put down enough information? Are the shop drawings accurate enough?”

The pinch points of the process, according to O’Connor, are usually where one building system stops and another begins. The system’s attachment points, whether those are mullions, steel joists or other systems are far more likely to fail than any internal system. So if a system performs well on paper, does it still perform in the field when it’s subject to the vagaries of the construction process?

“BIM can aid GREATLY in this pinch point,” O’Connor said. “An exchange of information and responsibility from the curtain wall manufacturer to the designer to the contractor can eliminate a lot of that vagary.”

BIM and Building Enclosures:

The Winter BIM Forum meeting in San Diego will showcase how teams are finding process improvements that result in better buildings. Focus topics will include:

•    Acoustical Analysis

•    Cost Analysis

•    Curtain Wall and Cladding Engineering

•    Envelope Trade Coordination

•    Facility Management

•    Laser Scanning

•    Legal aspects

•    Lighting Analysis

•    Model Level of Detail (Design vs. Construction)

•    Pre-Construction Planning, site layout and site staging

•    Pre-Fabrication & Constructability Analysis

•    Structural Engineering related to the envelope

•    Thermal and Energy Analysis

Many of the presentations will focus on informal building envelope team integration, whether  that is through money set aside for integrated planning or meetings by design and construction teams, Ikerd said.

Stephen Hagan, FAIA, director of project innovation at the US General Services Administration and Roger Grant, CSI, CDT, technical development consultant on projects for the Construction Specifications Institute and National Institute of Building Sciences, will present on the future direction of BIM and enclosures. Their presentation will answer where the industry needs to go with BIM and envelope analysis. What effort is required for the industry to be able to use enclosure simulation, digital fabrication, constructability analysis, and installation tracking entirely electronically. What is next big effort to automate our industry as it relates to BIM and enclosures and how will it come about?

Consulting Engineers from Simpson Gumpertz & Heger, a firm that specializes in building enclosures, will present “Analysis Tools in 3D for the Building Envelope,” a program that will also cover the latest in sustainable building envelope design using BIM tools.

Acoustician and auditorium and theater designer Acoustic Dimensions will focus on BIM model-based acoustical design and how it was used on projects such as the Manhattan School of Music and Hard Rock Live! In Orlando, Fla.

Enclosure consultant and structural engineer Will Ikerd will present on practical approaches to BIM enabled envelope reviews during construction. The presentation will highlight approaches and strategies that construction managers should consider when working with trades that may be new to BIM.  The envelope trades discussed will include curtain wall, masonry, metal panel, drywall, waterproofing, insulation, roofing, and precast systems.

The BIMForum is the can’t miss event on Building Information Modeling in the construction industry. To see who attended the last meeting click here.

Hotel Reservations at the Hard Rock

Additional Resources:

Excerpt on Building Envelopes from Brunner & O’Connor on Construction Law

Bringing Building Information Modeling into the Glazing Industry by Will Ikerd