There are two kinds of templates. The rubber stamped kind where all the websites look the same(usually rental sites or corporate agent sites provided by their brokerages). There are also a number of real estate formatted basic templates for the DiY crowd, but the customizations are limited.
And then you have foundational templates, which are essentially blank slates. A professional website developer can use these canvasses to build semi-custom websites. These literally have hundreds of thousands of limitless design scenarios which are 100% customizable.
With these foundational design platforms, the days of needing a full custom websites are gone. There was a time, before foundational platforms were developed, if you wanted anything unique, you would have to hire a designer to start from the ground up with only code. Those sites ranged in price from $5,000 to $50,000. There are a few clients that might need a full custom. Large brokerages, franchises, or sites with nationwide searc