While local JWs raised funds for the majority of KH construction costs, WT had long provided mortgage funding for any remaining funds needed, initially charging interest for the entire term which later changed to interest-free since a non-profit religion with charity status is not in the mortgage business and should not be charging interest. More recently, WT 'forgave' all outstanding mortgages so congregations are no longer required to make mortgage payments, but WT then 'requested' those same payments ... or more, to be provided to WT as a continual donation with no end term. Congregations without a mortgage were 'requested' to provide similar ongoing donations. Additionally, all congregation funds in excess of $5K, were then required to be provided to WT as a donation.
Although KH ownership was initially under control of 3 local trustees, usually elders, I understand WT has long required specific wording in each congregation' incorporation documents that specified ownership of each KH is to be transferred to WT if the owning congregation is deleted or otherwise ceases to exist.
WT had long ago implemented Regional Building Committees. All KH construction or renovation projects required RBC input and approval before proceeding, even when funding and labour were to be supplied by local members.
I recall in one congregation we were then involved with, local members wished to renovate, update and redecorate the existing building which was only <20 yo at the time. Funding, including regular monthly expenses, was an ongoing issue for that small rural congregation.
The RBC 'recommendation' was against renovating but instead replacing the building with a style of RBC choosing. As the majority of elders were company men, they unquestioningly supported the RBC's recommendation even as the majority of congregation members were opposed to a higher cost new build.
It was then standard practice to present such decisions to the congregation for a vote, but, the majority were not in favour so instead of accepting the congregation's decision for a renovation only, a vote for a new KH became a regular agenda item for numerous weeknight meetings until those apposed eventually weakened and caved in and the required majority votes in support for new KH was eventually obtained. I seem to recall that may have taken several months. I also recall, the elders who were in support of the higher cost new KH, all moved to other areas soon after the new KH was constructed.