I would like to know if it's a good practice for SEO to include very similar pages in the sitemap.xml file.
Context:
I have a real estate website, with listed projects (buildings), and each project has multiple properties for sale (apartments). Each property in a project has it own page, because it has minor differences (price, apartment number, floor number, etc), but almost all the page content is the same for all the properties in a project, including most of the text.
My doubt is if asking Google to index every single property page (via sitemap.xml) could be penalized because most of the content could be seen as duplicated.