A new site developer can do a sweetheart deal with anyone they want ,the site is private property until the roads and footpaths are adopted by the local authority, which is usually at least a year or three after the last plot has been sold ….if this site is OFNL only , then the developer had an arrangement to only allow OFNL access to the site during construction.
If there are some jointboxes with Openreach lids may say BT , but as Openreach and not BT have had responsibility for BTGroups network build since 2006 , then presumably the box or boxes are quite old and probably existed before the development was started, is this site built a green field or brown field development, if brownfield then it’s not unusual to have some legacy network elements still visible from before the site was cleared and ‘sold’ to the developer.
Your assertion that your property could get FTTP or FTTC is unlikely, the chances are no Openreach network exists , some properties on the extremities of the site , that front onto already ‘public’ maintained areas may possibly have access but in general if OR were locked out during construction of the development, there won’t be any service until a retro build scheme is delivered, and that’s not possible until the council adopts the area and even then it could be a very long wait before anything is done .
