Free Revit families
Some people work to tight deadlines and don’t have the required free hours in the day to build up their Revit libraries. This is where online libraries can be so valuable. They can help save time and increase model options by allowing users to download ready made content. Some of the content is manufacturer specific, which means it can be integrated as ‘real-life’ products into projects at an earlier stage.
 Reliability of Revit families
It can be hard to tell how a Revit family has been made and to anticipate how it will behave when brought into a model. Some free Revit families are good and some are bad, so it's important to be prepared to spend a significant amount of time getting them up to the required standards.
This post features a list of popular BIM and Revit online libraries with free content to download. Users are invited to try them and include evaluations in the comments section at the end of the article.
 1. BIMsmith (US)
BIMsmith is an online resource with lots of free Revit families to download. There is a good mix of products, but generally centred around architectural families (lots of furniture, lighting, appliances etc.) which makes sense as the site and content are created by former architects.
They also have a tool called BIMsmith Forge, which helps users create flooring, wall, ceiling and roof assemblies layer-by-layer and then downloaded as a system. On top of that is MyBIMsmith which features free, private cloud storage for any of these families. This allows users to save their favourite families or configurations and come back to download them later.
The UK has been leading the way in BIM adoption and standards, and therefore all families available have been created to the NBS BIM Object Standard. This standardises things like IFC and COBie parameters, meaning they contain a lot of data which is useful for interoperability.
 3. BIM Store (UK)
Similar to the NBS, BIMstore creates all free Revit families according to the ‘BIM Store Bible’ which is a best practice family creation guide. Containing IFC and COBie parameters - with a wide range of content from UK Manufacturers – this is a great site to find content.
 4. BIM Object (Intl)
BIM Object now hosts all of the Autodesk Seek’s BIM content, which means users can find a range of manufacturer specific content from all around the world. It is easy to search by brand, catagory, materials, building types and functional spaces.
 5. Modlar (US/Intl)
Another BIM library with a wide range, this site offers manufacturer specific content as well as user created generic content. A helpful feature allows users to search by country, so it's possible to find families that are relevant to a specific location/market.
 6. RubySketch (Aus)
 7. SpecifiedBy (UK)
This is a resource for manufacturer specific content from a wide range of product catagories. They claim to have “the largest library of BIM content in the UK”, and the site is easy to navigate, search and filter so users can find exactly what they're looking for. All Revit families are supplied by the manufacturers (not by SpecifiedBy), so content quality could vary from product to product. Nevertheless this helpful for users who are looking for free Revit content.
 9. Revit City
Similar to above, Revit City has many families to download (more than 17096 at the time of this review). These have been created by a lot of different users without a set standard, so quality is hit and miss.
 11. Smart BIM Library
 13. BIM Catalogs
 14. Polantis (Euro)
This site offers a wide range of 3D content, but many of the Revit families are not “true” Revit familes in the sense they have been created in other 3D programmes and just imported and saved as a Revit family file. UPDATE: Polantis says most (if not all) 3D content is now made with Revit, so users should have no issues with them not being “true” Revit families.
 15. BIMbox (UK)
BIMbox has a decent amount of Revit content available for free download. Most of the content is geared towards interiors (sofas, tables, shelving and so on), and the site is well presented. Most Revit content is IFC compliant as well.