Generally landscapes are not copyrighted, but some buildings can be.
Landscapes are never copyrightable and you have confused yourself with copyright on buildings.
Some architectural works are copyrightable, but if you take a picture of the building than you have not infringed the architect's copyright and have created your own copyright with your new picture. See section 120 of the Copyright Act of 1976. The confusion might come from the fact that switching media (steel and concrete to film) does not keep you from infringing except in the case of architectural works.
If photographs are put on a site purely for this reason, is this classed as "Educational" under the term 'free use'
You are not an educational institution or organization. You are also not a not-for-profit-business or charitable organization. These both create problems for "educational" and "fair use". There are only a few specially permitted uses under the statutes and they are for the blind, the deaf, libraries, churches, charity organizations, VFW, the Elks, and use for parody. Even these people have many restrictions such as music only, event size, notification, etc.
Some points the court's consider (and you should too) when determining fair use are:
1. Purpose and character of use. (i.e. Altruistic; socially desirable). Remember that money doesn’t create a presumption of unfairness.
2. Nature of the copyrighted work. ( It is more likely to be fair if it’s a science hypothesis--which is considered ok to copy more of--than if it’s sculpture or photography)
3. Amount and Substantiality of the part taken. This is the only factor that is not determinative.
4. Impact on potential market for the original work (This is the major weapon of the plaintiff and the biggest factor).
You should also know that there is no concept of fair use akin to “fair comment” in defamation law.
If you are worried about not having the model releases than the problem is with the person's right to privacy and not the copyright. If you are worried about having the property release, then do not worry unless it is private property and you are selling it or using it for advertising. Even public parks owned by private individuals cannot really restrict your use. Private owners that allow public to roam and even areas that are just plainly visible from the street really have no right to recovery. They can threaten and they can sue, but it would be a very tough battle for them to recover on a copyright basis.