It’s in the details, it’s always in the details: Building Envelopes

by Don Greulich

February 2016

One of the most critical components, if not the most critical component, of a building is the envelope. This may seem obvious, since the envelope protects the building interior and structural components from water, temperature, moisture, air and sound. But, often it is taken for granted and this can be a costly mistake.

Over the years building envelopes have become more interesting, unique and artful but also more difficult to design and construct. Building exteriors are intended to capture the beauty of the building and to protect the building. The construction may be with traditional types of construction or with new, innovative materials and methods. Often, these new materials require more investigation during design and certainly more care during the installation. New designs can be complicated and new products are not usually time tested, though their use should not be discouraged.

We have found, in the past several years, that these efforts need to be thoughtfully assessed in the conceptual stages with the owners, designers/architects/engineers and constructors. Questions such as; Has the assembly been used before? What will it cost? Can it be easily constructed by the trades available? Can the schedule include adequate construction time? What are the consequences if it is not properly constructed (water intrusion, high operating costs, material failures)? Is the installation reversible; that is can it be repaired or corrected if it is not installed properly?

Once a construction type is selected, what is the best approach in providing for a successful conclusion? A collaboration between the most experienced and most innovative (youngest) is the answer. The details should be created and reviewed by the most experienced people. They will know where the failures are hiding. There are collateral issues with penetrations for windows, electrical conduits, plumbing, structural components, vapor barriers/retarders, drainage means. One of the most critical costs are the possible mechanical system initial cost increases and energy costs. Wall construction details from which these penetrations and components are constructed are often created by the least experienced, possibly due to time constraints. Working with the younger, more innovative staff can produce better results, but experienced oversight is required. This seems to be true for both design and construction.

There is a careful balance between innovation for aesthetic purposes and functional performance. Close attention to the details can close this gap, reducing the inefficiencies. In future articles, we will delve into specific detailed topics including operating costs associated with building envelope failures and successes. Many of us have been involved in building envelope certification, moisture intrusion and operating costs and how problems can be controlled or avoided because of the influence it has to the HVAC systems.