Skip to main content

The word “grade” is used to indicate the earth’s level at a particular area or the ground level. The parts of a building that are either above or below the ground can be referred to as being “below grade” or “above grade,” respectively, in construction. There are many structures in commercial construction that go down one or more storeys.

The region of below grade residential construction offers a useful area that can be utilized for parking, mechanical and electrical rooms, offices, storage facilities in medic construction, and other uses. To avoid problems like water leaking into the basement, poor indoor air quality, and high humidity, building an efficient enclosure in below grade rooms is the key task.

With careful commercial construction planning and study, these problems can be avoided despite the fact that they severely disrupt building operations. Sadly, comprehensive analyses of the below grade system are not frequently requested, and as a result, enclosures with subpar performance are widespread.

How Come It Matters?

The same as above grade status, below grade status, is significant because square footage is not taken into account in real estate listings. In residential construction, you need to be aware of everything’s position when it comes to the ground. On paper, naming anything below grade provides additional information about the home’s layout because a basement is not the same thing as an upper floor. Three rooms above grade and a single room below grade are very different from having all of them on an upper floor.

The Creation of a Below Grade Enclosure System:

When constructing below grade systems, two crucial factors must be taken into account: the endurance of the building materials and the endurance of the structure itself. A below grade system cannot be easily adjusted and must be planned for the whole service life of a structure, in contrast to other construction components that can be changed repeatedly:

  • Accessing systems below grade is challenging, which raises the price of maintenance and improvements. It can be quite expensive to repair underground infrastructure.
  • Instead of focusing on the initial cost, consider the life cycle expense while choosing the components and design for a below grade system.

Waterproofing is essential for features that utilize some below grade areas like vaults, tunnels, or other sorts of expansions. Particularly when tunnels are involved, above waterproofing is crucial. Other crucial design elements are drainage and thermal insulation.

Below grade systems can deteriorate due to a variety of causes, including excessive moisture, temperature effects, weathering, heavy traffic, chemical exposure, overloading, and incorrect material selection. Inadequate design choices and subpar construction can also lead to rapid degeneration.

Fundamental Ideas for Below Grade Systems:

Slabs on grade, plaza decks, and foundation pillars are the three basic components of a below grade enclosure. These components must collectively fulfill the following four tasks:

Support for Structure:

The below grade system is regarded as a component of the building’s structure. Its duties also include transferring and supporting loads put on it by the surrounding area and the structure itself.

Environmental Control:

Any load brought on by the segregation of the internal and external environments must be controlled by the below grade system.


The interfaces between the inner and outside environments are the surfaces of enclosures. These surfaces need to adhere to a number of quality standards, including wear resistance.


The below grade enclosure must connect with building systems such as HVAC, water, gas, electrical power distribution, communication, and security.

Waterproofing Principles:

Controlling moisture is a crucial component of a successful below grade system. According to Michael T. Kubal, an authority in waterproofing for buildings, as much as 90% of all water penetration problems occur within 1% of the total building or outside surface area. Therefore, it is crucial to pay attention to detail when building below grade enclosures, particularly at wall penetrations and linkages with neighbouring elements.

Roof penetrations, door and window frames, and tie holes at the intersections of walls and floors are some building components that are frequently susceptible to water leakage. A possible difficult location for water leakage is, generally speaking, any interaction between building materials that is disclosed to the outside environment.

Kubal also makes the important claim that reasons other than materials or equipment failure are responsible for about 99% of waterproofing breaches. According to logic, this relates to human error, and mistakes are typically a result of poor design or construction. Some typical installation errors that might cause waterproofing problems, include the following:

  • Building system components that were improperly installed.
  • Recommending parts that are inappropriate for a specific application.
  • No preparation.
  • Inadequate primer is being use.
  • Areas where materials that are incompatible come into touch.
  • Concrete’s cure time was insufficient.

In order to accomplish good waterproofing, the design and building process is crucial because the majority of leaks take place in a tiny region and material flaws are uncommon. However, this also presents a chance because expert installation and design can reduce water leakage problems over the course of a building’s service life. When building components interact with places where they are exposed to water, more care must be taken.


In short, below grade construction is the kind of construction that is done beneath the ground level, for rooms like basements, storage areas etc.


Steve Hosten is currently a Writer for Sky Blue Construction based in Canada. Prior to joining Sky Blue Construction in August of 2022, he was an Architect writer. Steve studied Architecture, and Engineering from University of British Columbia.

Leave a Reply