Three factors to consider when designing New Building Envelopes

Written by: Dana Pezzuti, Director, BE Structural

Much like a human being has skin, an outermost layer,so does a building. This is its “ envelope” or sometimes called its “ facade”. A building envelope is not only the outer, visible layer but also what is under it. Often thermal and moisture barriers are installed under an outer layer to protect a building’s exterior and interior.

One of the most common causes of building envelope failure is moisture. When water infiltrates a building facade, its first line of defense; the structure is exposed to multiple risks.

Not only can structural damage occur from unwanted water but mold and biological material can begin to take hold causing a secondary problem sometimes worse than the initial structural damage-

Some types of mold can cause serious health risks and even fatality, if left un-treated.

A bad building envelope can turn a beautiful, new building into unusable space within a short amount of time.

Because the building envelope must work as part of a larger ecosystem, it is crucial to design one that takes into consideration all aspects of new design and construction.

Below we have outlined a few important factors to consider before designing a new building envelope

1.What is the building use?

If the structure in question is a new medical facility or hospital, indoor air quality is of the utmost importance. Within a hospitals’s walls, there is a myriad of factors to consider including the health and welfare of its occupants, expensive machinery potentially vulnerable to extreme temperature or water as well as building location.

2.Where is the structure being built and what is the climate in that geographical area?

Often, a thermal barrier is used under a building’s exterior to make sure the transfer of heat and energy happen effectively for its natural surroundings. For example, in climates where winter brings cold temperatures and summer hot ones, it is important to design a building envelope that can perform well in both extremes.

However, in a climate where weather temperatures do not fluctuate greatly, a different approach is necessary.

Lastly, a building envelope must be prepared to withstand natural weather events in any given area and meet not only local building codes but also industry standards.

3.What types of major storms and weather events  occur where the new building is occurring? Are extra measures required under the local building code to prevent failure in the event of a hurricane?

A qualified engineer or architect is the best professional to hire for building envelope design and planning.

Even with a qualified professional, the building envelope can be compromised if a design flaw or construction error occurs. This is why this complex system is now getting more attention. It is no longer a “ feature” or afterthought. It must be considered in the earliest design stages much like a building’s foundation.