* **building:** Handle cases of duplicate vertices with try/except ([03fdb73](https://github.com/ladybug-tools/dragonfly-core/commit/03fdb73fab52dfc02ce77de22293093240d3dc23))
* **default:** Do not use mutable objects for input argument defaults ([4d9946b](https://github.com/ladybug-tools/dragonfly-core/commit/4d9946b011192ad83ec804585afa8722d664e901))
* **model:** Add properties for units_system and tolerance ([da4d57e](https://github.com/ladybug-tools/dragonfly-core/commit/da4d57eba5aea3dc30f28a86f745bd593bed27e1))