What is a Building Envelope?

Building envelope
From Wikipedia, the free encyclopedia


A building envelope is the separation between the interior and the exterior environments of a building. It serves as the outer shell to protect the indoor environment as well as to facilitate its climate control. Building envelope design is a specialized area of architectural and engineering practice that draws from all areas of building science and indoor climate control.

Building envelope design includes four major performance objectives:

* Structural integrity
* Moisture control
* Temperature control
* Control of air pressure boundaries of sorts

Control of air includes air movement through the components of the building envelope (interstitial) itself, as well as into and out of the interior space, which affects building insulation greatly.

The physical components of the envelope include the foundation, roof, walls, doors and windows. The dimensions, performance and compatibility of materials, fabrication process and details, their connections and interactions are the main factors that determine the effectiveness and durability of the building enclosure system.

Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier. Moisture control is essential in cold climates. See dew point, condensation, and toxic mold.

Building Envelope Thermography involves using an infrared camera to view temperature anomalies on the interior and exterior surfaces of the structure.

In a city planning and zoning context, the "building envelope" can be 'the three dimensional space created by the designated setbacks and height restrictions in place for a zoning district'.

Upcoming Building Envelope Conference

Building Envelope Conference
Vancouver Program
UPCOMING EVENT
Building Envelope Solutions Vancouver
September 23, 2010
Vancouver, BC
Fairmont Hotel, Saturna Island Room, 900 West Georgia Street
2009 Conference Program
Event Details

Thursday, April 30, 2009
Hyatt Regency Hotel
655 Burrard Street, Vancouver, BC

8:45 a.m. Introduction & Opening Remarks

9:00 a.m. - 10:30 a.m.
The Building Envelope: How Passive Design and Envelope Affect Comfort and Energy

The envelope of a building plays a big role in maintaining comfort and reducing energy consumption. This session explores how the basics of passive design and optimum envelope performance affect the energy and comfort performance of a building.

Project examples highlighting envelope and passive design of sustainable buildings will be shared along with the findings of the City of Vancouver's Passive Design Best Practice Guide. The City of Vancouver has a goal to meet for 2010 and this Passive Design Best Practice Guide will play a role in meeting these goals.

Albert Bicol, Partner, Cobalt Engineering
David Ramslie, Sustainable Development Program Manager, City of Vancouver

10:30 a.m. - 10:45 a.m. Refreshment Break

10:45 a.m. - 12:00 p.m.
What Are Your Envelope Retrofit Options, and What Will They Cost?

A building envelope retrofit can achieve the perfect balance between the economy and ecology. The financial rewards gained by using qualified professionals and trades people are long lasting, and a long-term investment approach can yield better returns than the financial markets.

Reduced energy use not only saves money, but it significantly reduces greenhouse gas emissions. What are your envelope retrofit options? What do they cost? This presentation will provide an overview, and correlate how building specifiers, designers, and owners can evaluate their options to pursue a green rating certification, and/or get involved in Tower Renewal; and the benefits and challenges of building overcladding will be featured

Pierre Gallant, Principal, Morrison Hershfield Ltd

12:00 p.m. - 1:00 p.m. Networking Luncheon

1:00 p.m. - 2:00 p.m.
An Overview of Rating Systems and Net Zero Buildings, and the Effect the Building Envelope has on a Green Building

This presentation will cover the range of building assessment systems, from LEED and BOMA BESt (formerly Go Green), through to Net Zero buildings. What is "green" or "sustainable" and what does that mean in the context of building design decisions and material choices? Understand how to design with, specify, and integrate green materials, and the environmental impact of envelope material and installation choices.

David Fookes, Principal, Morrison Hershfield Ltd

2:00 p.m. - 2:15 p.m. Refreshment Break

2:15 p.m. - 3:15 p.m.
Mould, Moisture and Related Problems

Perhaps the most significant statement ever made about building science was that "Except for structural failure, about 90% of all building problems are related to moisture in some way". This presentation will discuss how these moisture issues can develop into mould issues that affect the indoor environment. When building envelope fails, mitigation of issues related to the indoor environment are often overlooked. The speaker will detail guidelines related to mould affecting the indoor environment in addition to assessment and investigation techniques.

Michael Glassco, Operations Manager, Theodor Sterling Associates

3:15 p.m. - 4:15 p.m.
Litigation and the Building Envelope: An Assessment of the Critical Issues

This session will identify the legal issues that may arise when a building envelope is found to be defective and requires remediation. Who is exposed to building envelope litigation, and what is the underlying rationale for their liability and the insurance issues relating to their defense and indemnification? Amongst the topics covered will be the professional's responsibility, builder's responsibility for faulty work product and materials, liability of local authorities and the impact of various exclusion clauses in the insurance contracts.

John Singleton, Q.C., Partner, Singleton Urquhart

4:15 p.m. Conference Adjourns

The Building Envelope: Barrier System

The barrier system seeks to keep water completely outside the envelope. This system has no redundancy or additional line of defense to deal with water that infiltrates the barrier. Since it is almost a foregone conclusion that at least some water will get into the system and must be able to drain back out, the barrier system is not recommended in a marine environment like the one we enjoy in Seattle. The new kid on the block is the rain screen system, which has a redundant, pressure-equalized waterproofing barrier — effectively an air space that reduces pressure drive. The building envelope provides the thermal barrier between the indoor and outdoor environment, and its elements are the key determinants of a building's energy requirements that result from the climate where it is located. These fact sheets and handbooks provide information about thermal barriers and energy conservation as related to the building envelope. Attic Radiant Barrier Fact Sheet Learn how radiant barriers can help reduces air conditioning loads and indoor heat loss. In this manner, the vapour barrier (in this case made of foil scrim kraft paper, called ASJ, All Service Jacket, aluminum on the inside, white paper on the outside) can remain intact as it penetrates the fire barrier. A vapour retarder and an air barrier serve to reduce this problem but are not necessarily interchangeable. These types of vapour barriers have been losing popularity to polyethylene sheets. Whatever type of vapour barrier you use, remember that its function is to block water vapour from reaching the insulation. There are also "reflecting" vapour barriers available on the market. The vapour barrier ensures a waterproof barrier between the exterior and interior of the house. Install strips astride the partitions. Types of vapour barriers: The vapour barrier is not to be mistaken for air barrier material that covers the outside of the intermediate envelope of the building (fibreboard).

Building Envelopes

Building Envelope: Thermography involves using an infrared camera to view temperature anomalies on the interior and exterior surfaces of the structure. Building envelopes can manage the same range of matters as the residential development provisions in effect in Victoria. A building envelope is the separation between the interior and the exterior environments of a building. Control of air includes air movement through the components of the building envelope (interstitial) itself, as well as into and out of the interior space, which affects building insulation greatly. The dimensions, performance and compatibility of materials, fabrication process and details, their connections and interactions are the main factors that determine the effectiveness and durability of the building enclosure system. Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapour barrier. In a city planning and zoning context, the "building envelope" can be 'the three dimensional space created by the designated setbacks and height restrictions in place for a zoning district'. The development provisions for residential subdivision provide for the creation of building envelopes. The residential development provisions for single dwellings under the Building Regulations 2006 recognize building envelopes in certain circumstances. The Kit provides information for land sub dividers, land surveyors, town planners, municipal councils, housing designers and building surveyors on creating, assessing and applying building envelopes.