Construction Moisture Management: Catch Up or Lawyer Up
Moisture in buildings has become increasingly worrisome for construction professionals in recent years. American buildings are subject to a wide variety of defects related to water in its different forms – liquid, vapor and sometimes snow and ice. These range……
The Window as a “Solar Panel”: Light Transmittance & Solar Factor G
With this article, we cover two very important aspects of glazings: light transmission and the solar heat gain coefficient. These parameters are extremely important for performing buildings and passive houses, however they are often overlooked by both designers and window…
The glass edge thermal bridge: the PSIg value
We continue our series of articles on thermal efficiency of windows, describing the glass edge thermal bridge. As far as thermal bridges go, this one is inevitable, and it represents the weakest point of a well designed thermal envelope. It…
Energy efficiency of windows: the Uf value
After covering thermal transmittance U and resistance R of opaque assemblies, and insulated glass, we now cover one of the most critical areas of the thermal envelope: window frames. Good windows are the cornerstone of a performing building for both…
Thermal Transmittance U vs Th. Resistance R
To achieve thermal comfort and energy efficiency in buildings, a primary role is played by the thermal envelope: this is required to thermally decouple the indoor environment from the ever-changing external conditions, both in summer and in winter. The structures…
Insulation materials: discovering the lambda value
The lambda value of a material indicates its ability to transfer heat: this property is therefore very important in the design of highly performing buildings and passive houses. The information commonly available is unfortunately quite confusing: with this article, we'll…
Mold and condensation: if the solution is worse than the problem
We cover here two real examples of mold and condensation problems, with thermal insulation installed on the inside of existing masonry walls. In both cases, the solutions were chosen on an empirical basis, and turned out to be worse than…
What’s an insulation material?
With more and more people talking about building energy efficiency and passive houses, it has become more and more common to hear about insulation. In this article, we explain what an insulation material is, to try and shed some light……
Certified construction system for Passive Houses
The construction system certification is possibly the least known certification offered by the Passivhaus Institut, and yet it can help spreading passive buildings all over the world. We worked on the first system certification for passive houses in a warm…
PHPP 9: a misunderstanding?
At the 2015 International Passive House Conference in Leipzig, Germany, the Passivhaus Institut presented version 9 of PHPP, which includes many new features to design passive buildings. Many articles have been written about the new primary energy method and the…
Airtightness: why is it so important?
With this article, we address one of the most important topics in the field of energy efficiency: the airtightness of the thermal envelope. Whether the building is a new construction or a renovation, its airtightness plays an important role for…
Thermal bridges: the temperature factor fRsi
We continue our series of articles on the topic of thermal bridges: this time, we illustrate the fRsi value, which describes the thermal ”strenght” of a node under the point of view of internal surface temperatures. As we have explained…