Fenestration Forum: August 2013
By Brian Burton
Keeping up the facade
By Brian Burton
Facade engineering is a specialized building science discipline that
focuses primarily on documentation, assessment and/or resolution of
aesthetic, environmental and structural issues related to the building
Facade engineering is a specialized building science discipline that focuses primarily on documentation, assessment and/or resolution of aesthetic, environmental and structural issues related to the building envelope. The ultimate goal is to achieve acceptable levels of environmenatal enclosure of occupied space while ensuring the health, safety and comfort of the occupants. The activity also serves to maximize building service life and energy performance.
In today’s construction environment effective moisture management or mitigation are considered vital. The need for moisture mitigation results from the fact that most defects in new buildings are related to water penetration or accumulation in or near the building envelope components. It’s also a fact of life that when buildings fail to perform as intended addressing defects or deficiencies can be extremly expensive. In new buildings, the total construction cost of the façade may often be very close to that of the building structure. As a result independent advice from façade engineers assits owners and developers in balancing the commercial and technical risks involved.
Building enclosure systems also have to meet a long list of performance requirements. They must maintain the desired separation of interior and exterior environments with an acceptable degree of control. It is also essential that they are accessible for cleaning, maintenance and repairs. Durability, sustainability, occupant safety as well as aesthetics and economic considerations are part of façade design strategies. Fortunately the building envelope is rarely required to meet all of these requirements at the same time.
To enable buildings to achieve high energy efficiency and create a comfortable indoor environment for occupants in Canada’s ever-changing climate, façade engineers must also consider performance criteria that may include building physics, thermal characteristics, ventilation, lighting, solar control, acoustics and safety. Facade engineers are also called on to assess and plan for the loads that result from seismic activity, wind, temperature, construction, maintenance and more recently the impact of climate change. In today’s modern buildings the interaction between the many disciplines involved in the design, supply, installation, testing and operation of building facades has become increasingly complex. There is no doubt that we are indeed pushing the envelope (pardon the pun).
Facade engineers concern themselves with all aspects of the building’s envelope components design and performance above ground level, including cladding, curtainwalls, stonework, masonry, mortar and roofing as well as fenestration components, glazing, sealed units, sealants, gaskets and weatherstripping. On occssion they also evaluate railing systems and access/egress systems. Facade engineers also evaluate the performance of systems and materials with regard to sustainability and environmental impact for both new and existing buildings. For new buildings they may be involved in both design and design review, working in close coordination with the architect, structural, and HVAC engineers.
Facade engineering services often include design development for new construction as well as review of materials, acoustics and environmental issues.They are frequently called upon to undertake structural analysis of cladding and glazing and may be involved with development of specifications and construction documentation. Typically they will also undertake in-situ quality control inspections that may be supported by mock-up testing and evaluation. In the case of existing buildings, they often complete facade condition assessments that typically involve determining the mechanism(s) of failure or completion of defects surveys.
Facade engineers have to maintain a broad set of skills and knowledge, and can be valuable partners in the construction process.
Brian Burton is a business development consultant and is serving on the Personnel Committee for the CSA’s Certification Program for Fenestration Installation Technicians. His current interests include adaptive reuse of buildings, overcladding technologies, maintenance of the building envelope and the rapidly growing use of computers in construction. You can contact him at firstname.lastname@example.org or visit his new website at http://burtons-pen.com