What you should know about Building Envelopes


Are considering the purchase of a strata property? Does the words 'building envelope' both scare and bewilder you?

Most major condominium repairs are required because of a failure or poor craftsmanship of the exterior shell of the building. Here is an honest explanation of what a building envelope is, and what can be done to remedy the problem.


What It Is

The building envelope includes all the building components that separate the indoor from the outdoor. Included are the exterior walls, foundations, roof, windows and doors.

The performance of the building envelope is impacted by a number of sub-systems, such as heating, cooling and ventilating equipment, plumbing and electrical systems. The interaction of the sub-systems with the components of the building envelope, as well as certain activities of the occupants, can affect the performance of the building envelope.


What It Is Supposed to Do?


The building envelope should keep out:

  • temperature extremes
  • moisture, as vapour or as liquid
  • dust
  • wind

Additionally, to maintain durability, the building envelope should not permit weather elements to be trapped inside the walls. This may cause wall components to deteriorate and continue to decay. In the early stages, it can usually be remedied relatively inexpensively. As time progresses, costs increase exponentially.


Maintenance and Inspections

The building envelope, like your car, requires regular inspection and maintenance. Do not be lulled into thinking, "we haven’t had any complaints so everything must be OK!"

Some maintenance guides suggest the exterior of the building does not need much attention in the early years. The numerous failures of building envelopes in the coastal climate zone of BC suggests that it is wise to have an inspection program that starts in the first year of the building’s life and continues annually thereafter. This should be done by an experienced professional.

If problems can be detected early, before obvious damage is caused, they can be remedied at much less expense and while warranty programs are still in effect.


Preventing Problems

If your strata corporation does not have a schedule for maintenance and inspection of the building envelope:

  • Communicate the need for this precaution in writing to the strata council.
  • Attend the Annual General Meeting (AGM) and explain why a maintenance program is important.
  • Give examples of problems encountered by other condominium complexes that were aggravated by the lack of a maintenance program. (Some case studies are included in this guide.)
  • Put forth a motion at the AGM to ensure that there is serious consideration of the need for a maintenance program and that it is recorded in the minutes of the meeting.

    How Do You Know if There is a Problem?

A problem exists if there is:

  • no regular inspection and preventative maintenance program in place
  • mold or fungi formation
  • wood rot
  • water flowing down the sides of the building instead of running off from the eaves and drainpipes
  • wind blowing through the walls
  • peeling paint
  • cracked or missing sealants (caulking)

or if there are:

  • water stains on inside walls, ceilings or inside the foundation
  • gaps that allow the weather to get through the walls
  • pools of water on decks
  • windows that are wet on the inside

These symptoms may not all be related to a failure of the building envelope:

  • Some may be localized maintenance items that can be fixed relatively inexpensively.
  • Some may be caused by interior systems in the unit. For example, an unvented clothes dryer will create moisture inside.
  • Some are caused by certain activities of the occupants. For example, hanging wet clothes inside will create excessive moisture.