Retrofit Building Envelope: What to Consider When Improving Efficiency

Answer: Building envelope issues, which include problems with the physical separators (e.g., windows, doors, walls, etc.) between the conditioned (e.g., heated and/or cooled) and unconditioned environment of a building, can take several forms. An energy audit will typically identify energy inefficiencies in one or several of the following areas:

  • Improper alignment & operation of windows and/or doors
  • Broken or missing weather-stripping around windows, doors, conduits, piping, exterior joints, or other areas of infiltration
  • Doors and/or windows left open that shouldn’t be
  • Excessive expanses of glass on exterior walls
  • No insulation between conditioned and unconditioned spaces
  • Inadequate or water damaged ceiling/roof insulation
  • Blinds and curtains are not used to help insulate the building

The suggested measures when exploring a retrofit building envelope will vary based on your facility’s unique mix of inefficiencies, but what follows are some general guidelines.

Retrofit Building Envelope: Suggested Operations/Maintenance Savings Measures

  • Realign or re-hang windows or doors that do not close properly. In extreme cases, consider permanent sealing of windows.
  • Make sure automatic door closing mechanisms work properly.
  • Replace or repair faulty gaskets in garage or on other overhead doors.
  • Replace worn and/or broken weather-stripping and caulking.
  • Replace broken or cracked windows.
  • Post instructions near doors and/or windows being left open.
  • Assure that automatic door closers function properly.
  • When replacing windows, replace with thermopanes, utilizing the same casings.
  • Keep curtains and drapes closed in unoccupied spaces.
  • Before replacing water damaged insulation, repair roof where required.
  • Verify that vapor barrier faces the conditioned spaces and is intact.
  • Instruct personnel to close interior shading devices to reduce night heat loss in winter and to reduce solar heat gain during summer. Place reminders where appropriate.
  • Repair or replace damaged or missing shading devices.

Retrofit Building Envelope: Suggested Facility Measures

  • Resize exterior doors, making them smaller to reduce excessive air infiltration.
  • Add expandable separate enclosures, where practical.
  • Install self-closing doors on openings to unconditioned spaces.
  • Install a switch on overhead doors that prevents activation of heating and cooling units when doors are open.
  • Install vestibule doors at major entrances.
  • Where practical, cover all windows and through the wall cooling units when not in use.
  • In areas with constant strong winds, install wind screens to protect exterior doors from direct blasts.
  • Totally or partially insulate non-operable windows. Consider replacing non-operable windows with walls.
  • Install double-pane windows.
  • Consider adding reflective or heat absorbing film to minimize solar gain in summer and heat loss in winter.
  • Install adjustable outdoor shading devices.
  • Attach storm glazing to moveable sash of operable windows.
  • Insulate between heated/cooled spaces and outside areas, such as parking garages, porticos, storage, basements and attics.
  • Add new insulation to meet the recommended standard.

Share this article