Getting up to speed with Air Sealing Details

Article 103 of the 2009 International Energy Conservation Code (IECC) requires that construction documents include air sealing details. Detailing the building envelope air barrier is a relatively recent challenge for architects, but it is a necessary task for communicating these fussy requirements to builders. The details of laps, connections, splices, and transitions of these thin membranes and tapes are especially important considering the potential downside of an unintended hole in an otherwise tight building envelope. With increased attention to energy conservation and air tightness of the building envelope, a small hole - like a pin hole in a balloon - can wreak havoc in terms of heat loss, vapor transmission, condensation, and moisture damage to construction materials that are concealed from view.

Some architects - already tuned in to our responsibility for construction drawings that show how building materials and products meet and connect with one another - have taken up this challenge by developing a sheet or sheets of details that show typical air sealing conditions that apply to their buildings. Instead of burying this information in other details where it may be hard to read due to the thinness of the air sealing materials, they have developed details specific to the air sealing materials, showing laps and transitions within the air barrier system and at transitions and terminations where the air barrier must connect with other building components like flashings, doors, and windows. Necessary details may include full-size views and exploded views to effectively show proper lapping and isometric views to effectively illustrate 3-dimensional shapes and connections. The details should be designed to effectively communicate the air sealing requirements.

Rethinking the Cost of Time

Building design and construction have been governed in modern history by our perception of time as a cost-based commodity. Both design and construction are assumed to have greater competitive value if production time is minimized. The first cost is generally lower if it takes less time to design and build a project. We can recognize an inverse relationship between first cost and long term cost when we consider building products (e.g., cheap windows vs. expensive windows), where lowest first cost may lead to higher long term costs in energy usage, maintenance, and replacement. Yet, as a profession and an industry, we have not been able or willing to recognize the long term value of time invested in design and construction, such that more available time (if well managed) results in more integrated attention to systems and details that enhance long term building performance and optimize long term operating costs. This issue is most notable in our continuing willingness to commit to abbreviated time periods for design and construction. We talk about the value of high performance buildings in terms of energy efficiency and healthful environments, yet the market continues to demand speed over performance due largely to the long established premise that "time is money" - a premise that is reinforced by the owner who wants the building quicker and by the designer and contractor who must bid low to get the job and then minimize time in order to avoid loss. When minimizing time is the highest priority, long term performance may suffer. Owners, designers, and contractors need to rethink the cost (and focus) of design and construction time as they relate to long term building performance. We have come to recognize long term risks associated with fast food; fast design and construction deserve similar consideration.

Breaking Ground with New Consultants

It can take a few projects to work out the communication kinks with a team of consultants. Consultants who have worked together and with the same team are likely to develop a good understanding of what to expect from other team members: learned and, perhaps, unwritten protocols about information exchange - what to expect and when, and what you have to request. A new consultant may bring both the promise of talent and the risk of problems related to communication. The challenge for both architects and consultants is to spend enough up-front time talking about who will do what and how and when information will be exchanged. It's better to consider your assumptions about what the other party will do and openly discuss details that may otherwise seem too mundane for review, especially if the scope of work is critical to timely project coordination and completion. While a formal consulting agreement may already be in place with an established scope of work and schedule, the details related to scope execution and coordination are not always covered in such an agreement.

Consultants bring not only different talents but also different ways of thinking, so it is best to reach an early understanding about the expectations of each party.

Bidders Trust Bid Documents for Take-off

Estimating quantities from a set of plans prepared by another architect reminds me that bidders are likely to rely on the accuracy of the drawings when preparing a take-off for a bid. If the drawings are inconsistent or include discrepancies, those are likely to affect the bids, and they may lead to claims of extra cost during construction, if the successful bidder determines that actual construction of the design requires more material (and related labor) than the drawings clearly indicated. The claims may be disputed as unreasonable based on a documented requirement for the bidder to consider the greatest quantity in the event of a discrepancy, but the limit of practicality may be exceeded where determination of actual quantity for bids would require exhaustive review and computation based on various plans and details. Bid preparation is typically limited to a short period of time due to a combination of the scheduled bid period and bidder attention. This is stated not for the purpose of blaming either the designer or the bidder but instead to suggest that accuracy in bid documents should be optimized in order to obtain accurate bids and to minimize discrepancies and the related disputes. There is an old saying that close bids are an indication of tight documents, meaning that the bidders all saw and bid the same scope. Of course, experience also shows that bids vary for reasons that have nothing to do with the bid documents, but that does not detract from the advantages of well coordinated bid documents.

Building Science and the Risks of Experimentation

Science is experimental; it consists of hypothesis and experiment. The path to success can be littered with experiments that fail. Scientists learn to expect failure along the way and to live with experimental failure as the cost of progress. Scientific design is experimental, and it is accompanied by an expected risk of failure.

The growing popularity of building science today brings increased risks of experimentation to the mainstreams of the building industry and the practice of architecture.

Historically, building design decisions were based on long established and proven practices and material selections. Expectations of reliability rested on proven performance over years or decades or - in some cases - centuries. The practice of experimentation was left mostly to the fringes and outliers. Main-streamers tended to avoid products and systems that lacked a good track record. Established building technology was a focus of learning and skill building; architects and builders could expect to learn from a previous generation and practice for decades with a building technology that would remain essentially the same.

More recently, we have seen and become obsessed with an increasing pace of change. Many equate faster with better, making decisions based on the latest available product or on predictions of the next invention or innovation - perhaps even with a belief that it must be better simply because it is new and not established. However, this kind of experimental approach to building design and construction dramatically increases the risk of building failures, in large part because it discredits time-tested performance and avoids or dismisses time-consuming consideration of the multiple roles played by building materials and the roles played by parties in the construction process.

Valid interest in (and popular incentives for) conservation and quality of resources and processes may have led to a willingness on the part of some to take more risks with experimentation. But questions need to be answered: Who assumes the risk? How much risk? Is there awareness and consent of assumed risk? and, If it fails, who owns the failure? Further, If it fails, how can it be considered a sustainable practice?

A Few Predictors of Building Failure in New Construction

The following suggested predictors of building failure in new construction are based on years of experience tracing building failures to their causes. While the failures may express themselves as discrete detail flaws, underlying causes are often found in contractual decision making, project administration and management, and in conceptual design. The following predictors do not guarantee building failure, but they do indicate a heightened risk of failure.

1. Building from Schematic Design or other preliminary design documents – Schematic Design Drawings or other preliminary drawings that are prepared in CAD or a related computer program can appear quite precise, so it is possible to mistakenly expect such drawings to be sufficient for construction. Schematic Design Drawings typically lack sufficient detail for construction and may not be well conceived in terms of how materials and building components relate to one another. There is a high risk of building performance problems, including but not limited to building envelope leaks, when Schematic Drawings or other preliminary drawings are used as the basis of construction.
2. Eliminating or drastically limiting the Architect’s role during construction – If the Architect is dismissed from the construction phase of a project, or if the Architect’s services are reduced below the standard of practice in order to save cost or expedite construction, there is a heightened risk that changes and substitutions will be made without the review and scrutiny of the Architect, who would be expected to consider the compatibility of changes and substitutions with the design intent or even with code requirements and is expected to know more than contractors do about these matters. (Similar problems can occur if the Architect’s construction administration services are delegated to inexperienced staff, who may not have sufficient knowledge about the materials and systems they encounter on the construction site.)
3. Insufficient consideration of climate and weather – Success of building designs and design features in one climate are not good predictors of success in a different climate. This is true for building envelope designs in different geographic locations, and it is true for interior design features, materials, and details that are mistakenly used in exterior applications where they are inadequate for exposure to weather, including precipitation and exterior variations in temperature. It is also true for moisture sensitive interior materials that are subjected to high humidity related to building use (e.g., a swimming pool environment).
4. Assuming that the selection of an innovative, energy efficient product or system will, on its own, lead to a durable, energy efficient building – Examples include rot failures related to SIP (structural insulated panel) construction where panel joints were not properly sized and sealed and where OSB facing material was exposed to moisture in the belief (espoused by the panel manufacturer) that OSB was a waterproof material that need not be protected from moisture.

Certainly, there can be other predictors of building failure in new construction, and avoiding the predictors above may not lead to a trouble free building every time. Still, the issues above appear to be common enough to warrant their listing as predictors of building failure.

Planning for Concealed Site Conditions

Discovery of concealed site conditions can raise havoc with a project, possibly disrupting the construction schedule and adversely impacting the project budget. Here's a link to an article I wrote a few years ago to share some of my experience with concealed site conditions: Planning for Concealed Site Conditions

Delegating for Architects

Project results are directly related to the effectiveness of project communications. Successful delegation of responsibilities and tasks depends on effective communication. Download "Delegating for Architects" to read more about this.

Construction Documents Coordination Matrix

It may look a little "geeky", but this matrix can be an effective tool for considering interdisciplinary coordination needs. The design disciplines for a project are listed across the top and down one side. The intersection points represent coordination between disciplines (e.g., between Civil/Site and Electrical). Seeing the possibilities in this format can help to minimize coordination gaps. On a given project, the extent and specifics of coordination will differ from point to point, and the design displines may also differ. Still, seeing an intersection point can prompt thoughts about needed coordination between any two disciplines. For example, where Civil/Site meets Foodservice, it may bring to mind the need to coordinate the locations of exterior condensing units with site work. Etc. Etc. Etc.

Looking at this coordination matrix, it is also easy to see how extensive coordination really is (and must be) on an architectural project. On some complex projects, coordination can be seen as a full time job in itself, from the coordination of consulting agreement scopes of work to the coordination of sub-trade scopes of work and the dotting of i's and crossing of t's in construction documents.

Construction Documents Peer Review

Joe Iano (see Iano's backfill ) shared with me an approach to quality review of construction documents that is used by a prominent firm where he is employed in Seattle (see the AIA 2009 Honor Award Firm of the Year Olson Sundberg Kundig Allen Architects in the May 2009 issue of Architectural Record). Joe said the firm has senior non-project staff review construction documents together with staff who developed the documents for a given project. The issues, concerns, and comments that are raised during the review can go a long way toward mentoring less experienced staff.

A similar approach could work in utilizing the services of an independent peer review architect who can review the construction documents together with the staff who developed the documents. Compared to a "redline only" mark-up of drawings and specifications, the interactive review process can include a substantive conversation that carries longer term value for the firm, while taking advantage of review expertise outside the firm.

The 50-50 Rule

Jobs vary in the proportion of time required for technical work ("stuff") vs. people work (communication, cooperation, management, etc.). Some jobs may consist of less than 50% stuff, but most jobs done effectively require at least 50% people work. If you are doing a technical job in architecture (or most any other field), and you think that your job is 100% or near 100% "stuff" and 0% or near 0% "people", you are probably not doing your job effectively, and you are probably neglecting at least 50% (the "people" part) of your job.

When you develop drawings - plans, sections, elevations, details, etc. - and specifications, you depend on other people to understand and make effective use of those drawings and specifications to produce desirable results. Your work must effectively communicate with others, be they other designers, consultants, owners, users, permitting authorities, estimators, bidders, contractors, subcontractors, material suppliers, and others. And the value of your work - especially technical work - is diminished by the extent that it does not effectively communicate with others.

While jobs do vary in the actual proportion of "stuff" vs. "people", a good approach to a technical job is one based on a consideration that at least 50% of the job is people related. That's the 50-50 rule.

Email is Snail Mail for some

We all have our preferred means of communication, and we are inclined in this digital age to think that faster is better. But, in some situations, exclusive use of lightning speed technology may actually delay communication. The growing popularity of email years ago gave rise to the derogatory term "snail mail" to describe older and slower postal service or even "express" systems for delivery of hard copy mail.

But, for some, "snail mail" still beats email. In one situation an executive who touts his company's use of computer based technology remains reluctant to make personal use of it. Sending this CEO an email message actually guarantees as much as a 2-week communication delay. His orders to his assistant - who actually receives his email - is to print it all out once every two weeks and put it into his in-box in a neat stack. He may then read it along with letters, magazines, advertisements, and other mail.

This may seem like an extreme case these days, but it illustrates the importance (and advantage) of utilizing several means of communication to deliver a message. Don't forget face to face conversation, the telephone, the postage stamp, arm waving, signing, the bullhorn, and other potentially effective ways to deliver a message. (See also Practice the Hand-off.)

Can you recognize a flat tire?

One architect, when interviewing prospective employees, would typically say, "You may have to mow the lawn sometimes." There wasn't much lawn to mow around that office, but the statement was an effective way of saying that we all have to pay attention to practical matters, and that may mean doing a few things that are not on your personal career agenda. In the midst of rapidly advancing technologies, practical awareness and practical skills continue to be important and useful.

Specialization and automation risk some loss of practical awareness. As we come to rely more on technology and automatic systems, we can lose our internal ability to recognize a problem. The recent addition of a tire pressure monitoring system (TPMS) as a feature on automobiles exemplifies such a risk. While TPMS may signal a loss of tire pressure that is not obvious to an observer, the presence of TPMS is likely to lull a driver into thinking that it is not necessary to consider the condition of the tires before traveling. Then, if the TPMS malfunctions and does not signal the driver of a loss of tire pressure, there is a risk that the driver will continue to operate a car with an under-inflated or flat tire, possibly damaging or destroying the tire...or worse. "Hey! The TPMS didn't tell me there was a problem!" With or without TPMS, a driver needs to recognize the symptoms of a low or flat tire and to react appropriately. One of the long term effects of systems like TPMS may be TLOA (total lack of awareness).

GPS, spell-checker, and CAD (see CAD doesn't care) are other examples of helpful technologies that may, as a side effect, reduce our internal awareness of problems. In a similar way, BIM (Building Information Modeling) offers the promise of more ways to consider a building project in its formative stages, but it will still fall to the operator or viewer to recognize a problem that needs to be corrected (see What's wrong with this picture?).