Defining “Grey Shell” Construction

In the construction industry, there are many terms thrown around, and they can certainly seem confusing! For example, there are “shells” – vanilla shell, cold dark shell, and even “grey shell.” Not only that, but they have synonyms – a grey shell can also be called a cold shell, and a vanilla shell can be a warm shell or white box. What do they all mean, and why do they matter? In commercial construction, these are all various states of interior spaces before “tenant improvements” are implemented for building occupants.

Defining Cold Shells in ConstructionCommercial space occupants almost always need their new space converted for their needs from whatever it was previously (whether new or previously leased by someone else). These interior space updates are called “TIs,” or tenant improvements. They require experienced, competent builders to help identify, understand and execute the tenants’ building requirements for the space at hand. These TIs are what make the space customized and business-ready for day-to-day dealings with customers.

It is common for commercial interior spaces to be converted to, or start as, a “white box” or “vanilla shell.” This is a typical interior stage prior to tenant improvements. It can include: HVAC and electrical setups; finished, accessible bathrooms; concrete or finished floors; white painted walls; basic lighting in finished ceilings; and fire escapes.

As an alternative to the white box, there is an option which needs less upfront construction work, but more construction work to finish for tenants. This is the “grey shell.” Despite the additional work, there is a big plus to the grey shell for tenants: it gives them a lot more flexibility and design possibilities for executing the final TIs. These are the characteristics of a grey shell: Exposed, unfinished ceilings (no ceiling tiles); no sprinkler system dropped to final ceiling height; unfinished floors; no finished duct work (however the HVAC can be in place); unpainted and unfinished walls; no plumbing or electrical systems in place; existing point of connection for the sewer.

This explains the details that distinguish a grey shell from a white box in commercial interior construction, and how tenant improvements impact the options and requirements. See more on Buildrite Construction’s renovation services.