Enclosure design principles Documents

BSD-007: Historical Development of the Building Enclosure by John Straube — last modified 2008/08/20

Historical works, notably the Roman Vetruvius’ Ten Books of Architecture, that describe buildings begin with an historical overview. Archaeological and anthropological studies have furthered this understanding. The history of the built form and the building enclosure is more than just a curiosity: understanding the history helps explain many of the buildings types, construction techniques and building materials that we use today. This digest provides a brief overview of the development of the building enclosure and can serve as an entry point into a deeper historically-informed study of buildings and building science.

BSD-011: Thermal Control in Buildings by John Straube — last modified 2008/09/09

Providing thermal comfort without excess space conditioning costs is one of the primary requirements of buildings. Therefore, thermal control is an important aspect in almost all buildings. Understanding heat transfer and the temperature distribution through building materials and assemblies is also important for assessing energy use, thermal comfort, thermal movements, durability, and the potential for moisture problems. Heat flow occurs through the building enclosure via opaque enclosure elements, is directly transferred into the building by solar radiation through windows, is carried along with air across the enclosure by unintentional leakage and ventilation, and can be generated within the building by occupants and their activities. The control of heat flow in buildings requires insulation layers compromised with few thermal bridges, an effective air barrier system, good control of solar radiation, and management of interior heat generation.

BSD-013: Rain Control in Buildings by John Straube — last modified 2008/09/09

Moisture is one of the most important agents leading to building enclosure deterioration. Understanding and predicting moisture movement within and through the enclosure is therefore of fundamental importance to predicting and improving building enclosure performance, particularly durability. Since driving rain deposition on walls and roofs is quantitatively the largest single source of moisture for most walls and roofs, it is no surprise that controlling rain penetration is one of the most important parts of a successful moisture control strategy. In fact, failure to control rain is likely the oldest and most common serious building enclosure performance problem. Commentators as long as Vitruvius (70 BC) bemoaned the challenges of controlling rain penetration. This document will consider rain control from a general to a specific level. The following sections will cover: basic moisture control principles that should be employed in the design of above-grade building enclosures; driving rain as a moisture load on walls; a classification system of the various rain control strategies available for walls; and finally, good design practises for walls. The rain control of roofs will be covered in more detail in another BSD.

BSD-106: Understanding Vapor Barriers by Joseph Lstiburek — last modified 2008/10/17

The function of a vapor barrier is to retard the migration of water vapor. Where it is located in an assembly and its permeability is a function of climate, the characteristics of the materials that comprise the assembly and the interior conditions. Vapor barriers are not typically intended to retard the migration of air. That is the function of air barriers.

BSD-144: Increasing the Durability of Building Constructions by Joseph Lstiburek — last modified 2008/09/09

The current building industry focus on durability is in part a reaction to the current perceived lack of it. Warranty claims and callbacks are viewed as increasing. Litigation and insurance costs are felt to be rising as a result. Another reason for the current focus on durability is the recognition that sustainability is not possible without durability. If you double the life of a building and you use the same amount of resources to construct it, the building is twice as resource efficient. Therefore durability is a key component of sustainability. It seems that one thing that both the development community and the environmental community can agree on is that durability is a good thing. What do we know about durability and how do we know it? The lessons of durability have come principally out of failure. Engineering is an iterative process of design by failure. Buildings are constructed. Problems are experienced. Designs and processes are changed. Better buildings are constructed. The building industry is in essence a reactive industry, not a proactive industry. It can be argued that the industry continues to do things until they become intolerably bad and then the industry changes. Examining failures gives us guidance on increasing the durability of building constructions.

BSI-006: Can Highly Glazed Building Façades Be Green? by John Straube — last modified 2008/10/22

When I see a fully glazed, floor-to-ceiling commercial or institutional building, I see an energy-consuming nightmare of a building that requires lots of heating and cooling at the perimeter just to maintain comfort. The result, on a cold winter day, is that offices exposed to the sun require cooling, while those in the shade need heat.

BSP-041: READ THIS: Before You Turn Over a Unit by Building Science Corporation — last modified 2008/09/09

How a unit is turned over and maintained has significant effects on the control of asthma triggers and other indoor and outdoor contaminants.