Your building's envelope includes the walls, roof, windows, doors, and foundation. You can keep out the cold and make tenants more comfortable by closing gaps, cracks, vents, and other holes in the envelope.
In apartments and common areas, you can:
You can also go beyond basic solutions to further improve your building's performance and comfort. You can install foam boards, spray foam, or other fibers in the space between your walls and roof to stop heat from transferring across thin materials — even where there isn't a hole.
How to stop drafts in your building: