They are technically four organizations for
DVC:
1. DVD, the lead DVC company that develops and builds the timeshares, holds the long-term lease of the land on which they sit, prepares all the POS's, controls any new construction at an already existing resort, sells the timeshares, has the right of first refusal on any resales, forecloses on members who fail to pay dues, controls any DVC sales offices or booths at WDW. DVD always retains at least 2% of each unit in a resort, and can use that and ownership interests it acquires via right of first refusal or foreclosures, to reserve DVC rooms to the the public.
2. The association for each resort, whose directors and officers are all appointed by DVD, via a vote at an annual meeting in Dec that members can attend, but cannot vote because under the POS documents they have assigned all their rights to vote to DVD. The principal activity of the association is to enter into contracts with other organizations, principally DVCM and BVTC. Otherwise the association does little.
3. DVCM, the management company for each resort, whose directors and officers are all appointed by DVD,which is retained by the association to basically do all things an association would usually be required to do, except for those things that the association assigns to BVTC (next paragraph). DVCM enters into contracts with other Disney entities to provide resort transportation, security, and all the employees who work at the resort (who are actually not employed by any DVC entity, e.g., most are employed by the Walt Disney Parks and Resorts Co. (WDPR), and DVCM pays that entity for the portion of overall labor costs applicable to DVC Resorts). DVCM is also responsible for home resort reservations and centralized Member Services applicable to the reservation systems and generally any centralized Member Services relating to the combined resorts, other than those assigned to BVTC. DVCM can also put into the central Disney reservation system for renting any rooms at a resort that are still open at 60-days or fewer out from date of arrival (and, in reality, it can make those reservations before 60-days out based on reasonable estimates of what will probably still be open at 60-days out),
4. BVTC, the designated company that handles members exchanges with non-DVC resorts, and exchanges from outside resorts into DVC, and is responsible for the DVC Reservation Component of the centralized reservation system, which is responsible for all reservations made by members at 7-months out for DVC resorts the member does not own. Its officers and directors are all appointed by DVD, and in reality its reservation system is just part of the overall reservation system, and the employees for both home resort and non-home resort reservations are the same people.
In essence, all four of the entities are controlled by DVD. As to the construction of a new sales location at a DVC Resort, that would be DVD, although it would be communicating its plans to WPDR at WDW, the owner of the land, to assure it does not have objections to what is being done. As to who you would actually contact about such construction, that I do not know, and I cannot even find a phone number for DVD itself online, and going through the general DVC number for members does not offer any options that get you directly to DVD. Also, the corporate form of DVD was changed in Dec 2023. It was the "Disney Vacation Development, Inc.," before then, and is now the "Division Vacation Development, LLC," a limited liability company.