> For the complete documentation index, see [llms.txt](https://orbcity.gitbook.io/orbcity/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://orbcity.gitbook.io/orbcity/building/construction-system/concept.md).

# Concept

<figure><img src="/files/DqJKYW9AHz00RLOzaVYp" alt=""><figcaption></figcaption></figure>

In order to maintain a balance between supply and demand, the construction system introduces **"dynamic time variation"**. It takes a certain amount of time to construct a new building, and the time dynamically changes depending on the total number of building NFTs, i.e. **if the supply is high and the total number of building NFTs is high, the construction time increases significantly, and if the demand is high and the total number of building NFTs is low, the construction time decreases significantly.**

<figure><img src="/files/ulLwjcbiwmvs1oUdjxa6" alt=""><figcaption></figcaption></figure>

In the early days of this system, we expect supply and demand to be volatile, but over time we will want to **lock in the number of buildings to a certain number**, which will eventually be maintained through market logic and dynamic time changes.

<figure><img src="/files/9F7856J3Tqk6KyuneeMz" alt=""><figcaption></figcaption></figure>

As a result, $Lay 007 and $Orb will continue to be burned while the number of buildings shrinks and grows due to supply and demand.