The Building Enclosure Core reflects a very different perspective in enclosure design. The ‘Core’ refers to all elements of the enclosure with the exception of its exterior cladding system. It is both physical construct as well as resilience exercise as it embodies the most critical elements of air, moisture, and thermal management. Traditionally the industry…
On Steady State/Dew Point Assessment (Glaser Method): BS EN ISO 13788:2002 Section 6.1 This standard gives calculation methods for: a) The internal surface temperature of a building component or building element below which mould growth is likely, given the internal temperature and relative humidity – the method can also be used to assess the risk…
Extreme climatic conditions are those falling in the upper or lower tenth percentile of the local period of record. North American hygrothermal datasets rely on such extremes in simulating climatic effects on building performance. Prior to 2012, WUFI employed customized 30-year hourly data provided by the U.S. Department of Energy for the 1961-1990 period of…
Computer simulations rely on a variety of datasets when assessing the effects of climate on building performance. These data, and the models they power, provide an important basis for planning, design, and cost analysis. Below I describe some of the major types of climate datasets used in energy and hygrothermal modeling. Weather Years Datasets described…
Natural alternatives to foam insulation are highly desirable for high-performing wood-framed buildings. But lignocellulosic materials can be highly bio-nutritive and moisture absorptive, increasing their vulnerability to degradation and reduced thermal performance. Designers are often faced with the dilemma of selecting materials that are less environmentally safe for much improved performance. In this article, I describe a…
Adoption of the 2012 International Energy Code will require exterior continuous wall insulation for climate zones 6, 7, and 8. When used in combination with cavity insulation, the minimum requirements include 20+5 or 13+10. The first value pertains to cavity insulation whereas the second is continuous exterior insulation (CI). Although comparable insulation strategies are also…
Concrete masonry construction was common practice in post-war Modern architecture where it was used extensively in schools, churches, public buildings, and industrial complexes. Brick and concrete block-bonded construction gained favor in many public buildings for its perceived durability, aesthetics, and relative ease of construction. Over 50 years later, many of these buildings now have historic significance but suffer…
Quality moisture management relies heavily on guidance intended to reduce surface relative humidity below thresholds for mold. The companion to this approach is centered on using materials that are more resistant to mold either by using naturally resistant materials or by employing materials and products manufactured with chemical inhibitors. Mold-resistance strategies assume that materials can sustain…
Energy wall design has seen a resurgence in TJI and truss wall construction – sometimes employing exterior insulation in conjunction with their deep 12” to 16” insulation-filled cavities. The downside of this approach includes a high potential for cold sheathing and subsequent moisture accumulation during the winter months. The Risk Wood sheathing will accumulate moisture…
The IECC’s requirement for 1” continuous exterior insulation has prompted wall configurations that integrate various types of outbound insulating materials. With all of these systems, adequate considerations must be made for the amount of moisture penetration from wind driven rain and the presumed location of this moisture load. It is generally assumed that exterior surfaces of…
Energy efficient initiatives, coupled with the IECC’s requirements for continuous insulation over exterior surfaces, have prompted a vast array of ‘Frankensteinian’ energy assemblies. From three-coat stucco over outbound EPS to EIFS on structural insulated panels (SIPs), the combinations of such hybrid approaches appear endless. While the professed energy efficiencies can be impressive, moisture management may…
Moisture performance of EIFS is misunderstood and it continues to be a subject of consternation. Much of the confusion stems from the fact that design criteria for EIFS assemblies incorporating cavity insulation plus outbound insulation panels have not been adequately addressed by the EIFS industry. Manufacturers place the responsibility of assembly design squarely on the…
The Building Enclosure 