Modern Curtain Walls: 4 Simple Steps to Avoiding Costly Disputes & Performance Problems

There is no feature of a modern building that is more visible—and few that are more critical—than its curtain wall.

Brent Gurney, Andrew Cohn and Joshua Ferrentino

Andrew Cohn

Andrew Cohn

There is no feature of a modern building that is more visible—and few that are more critical—than its curtain wall.  If the curtain wall fails or does not perform properly, the integrity and value of the building can be substantially impaired.

The curtain wall appeared on the architectural scene in the early 20th century, when structures such as the famous Hallidie Building in San Francisco, a seven-story structure faced with glass and cast iron, began the shift away from the heavyweight masonry building styles popular in the 19th century.  Since then, the curtain wall has become the ubiquitous external feature of many contemporary buildings.

As they have become a common construction technology, the complexity of curtain walls has increased greatly.  As computer-aided design and materials science have pushed the boundaries of what is possible for curtain walls, the modern high-end curtain wall design and has come to have more in common with automotive or aerospace technology than traditional construction.  These are highly engineered building “envelopes” of incredible complexity, built with advanced materials requiring very tight tolerances

Joshua Ferrentino

Joshua Ferrentino

Curtain wall components are likely to be assembled off-site in sophisticated manufacturing facilities, using components drawn from numerous suppliers.  A curtain wall (glazing system) subcontractor is likely to employ dozens of its own architects, engineers, and designers, who can implement an architect’s vision for a free-form geometric façade, create a wall that will generate electricity with integrated solar panels, or an enclosure that will respond to weather and daylight conditions using built-in sensors, lighting, and shading devices.


Brent Gurney

When a curtain wall glazing system is designed, fabricated, and installed properly, it can be a technological marvel—a gorgeous and high-performing building skin.  When something goes wrong along the way, however, the inherent complexity in curtain walls can make it difficult to determine the cause of the problem, or to assign responsibility.

A building owner will want to ensure that it is not stuck holding the bag for defective work.  A general contractor will want to ensure that it is not forced to pay for a poor design or for subcontractor work that is subpar.  In the event that a curtain wall problem ripens into a dispute, each party’s rights will depend not only on the quality of the pre-construction performance specifications, the terms of glazing system warranties, and other documents, but also on being diligent and holding the  relevant counterparties to account.

Here are four ways that owners and contractors alike can protect themselves from being stuck with costly repairs and disputes, or an expensive building enclosure that doesn’t perform:

Act quickly if problems appear
This is a particularly important consideration for an owner.  Under the terms of a typical construction contract, an owner is in the strongest position if it requests corrections to work within one year of substantial completion (and, from a practical perspective, while it still holds retainage during the contractor’s completion of punch list items).  Additionally, the statute of limitations for many claims is likely to begin running from the date substantial completion, or from the date that a contractor or architect completes his work on the site.  For other types of claims, such as breach of a warranty, the clock may begin ticking when the warrantor fails to honor a request for repair.  No owner wants to be in a situation where it is left holding the bag from someone else’s errors because it failed to be assertive early in the game.  When a potentially serious defect surfaces, both owner and contractor alike should retain experienced legal counsel early on who can act as a strategic advisor, connect you with the right technical experts, and make sure that your rights are protected.

Rely on your experts
During the design, pre-construction, and construction phases, owners and contractors alike should press specialty subcontractors, architects, and consultants to provide information about the expected performance of design elements.  As your experts, they should be able to tap into industry knowledge about the performance of a given material or design feature.  That’s why you hire them.  Make sure system performance specifications in all contracts cover the full range of weather conditions a building will likely experience.  Require pre-installation testing of mock-ups to confirm the ability to satisfy specifications.  If something you see in a drawing or a mockup worries you, ask about it—and either get it fixed or get assurances in writing from the professionals that the as-installed element will perform as required without reworking.  It is in a contractor’s interest to engage in this type of diligence as much as it is for an owner, as finding and fixing potential snags early in the construction process may avoid costly delays, repairs, retrofitting, or disputes later on down the road.

Make sure the construction contracts and other documents assign responsibilities clearly.
From the owner’s perspective, it is advantageous to make the architect, contractor, and subcontractors responsible for success—not just for complying with the letter of the specifications.  In particular, an owner will want to make sure the contract documents place with the glazing subcontractor and other relevant suppliers the responsibility for delivering a successfully performing curtain wall system, and not just an aggregation of exacting dimensions and complex materials.  From the general contractor’s perspective, it makes sense to place responsibility for success on specialty subcontractors with appropriate subject matter expertise.  And every party—from the owner down to the subcontractors—benefits from documents that are clear about who must do what.  Investing the time to make sure documents are well-crafted can go a long way toward avoiding headaches for all parties down the road.

Get extended warranty coverage
In complicated curtain wall systems, problems may appear right away, or they may surface years later once a building is occupied, subjected to several seasonal cycles of weather, or other events.  It may be prudent to for owners to press contractors and suppliers for lengthier than normal warranties, especially for particularly complex or untested elements.  And if potential problems crop up after construction begins, or even after substantial completion, don’t be afraid to propose warranty extensions: these can be beneficial for all parties involved as they can avoid hastily filed and costly litigation and allow more time to investigate and reach a mutually satisfactory solution.

As architects, component manufacturers, contractors, and owners continue to break new ground in the design and installation of complex curtain walls, the appearance of challenges and disagreements is inevitable.  However, with careful diligence and the right expert assistance and strategic advice, these challenges need not ripen into problems that detract from the value of the building that all parties have invested enormous resources to create.

About the Authors

Brent Gurney and Andrew Cohn are partners at the law firm Wilmer Cutler Pickering Hale and Dorr LLP.  Mr. Gurney, a member of the firm’s Business Trial Group, is an experienced trial and courtroom lawyer who specializes in complex, high stakes litigation.  Mr. Cohn, a member and former chair of the firm’s Real Estate Practice Group, has handled major transactions in more than 20 states, involving the financing and development of office buildings and other major projects, and also has extensive experience with leasing, management agreements, construction and ground leasing.  Messrs. Cohn and Gurney have frequently collaborated as representatives and strategic advisors to clients on complex curtain wall design and performance issues. Cohn and Gurney thank Joshua Ferrentino, a former associate at WilmerHale, for his contributions to the article.