A fireplace or an oven is a nice addition to your home, but it might bring along additional worries as they are working with fire that is never completely safe.
The idea behind stainless chimneys is that a regular chimney is made safer with an extra feature. Stainless chimneys are made of a very heat resistant material; therefore they are very safe as chimney is exposed to very high temperatures. In stainless chimneys brass trims are used to cover the chimney support components.
These trims can be installed after the building of the chimney both by the owner but it is more recommended that you have it done by a professional, who installed the chimney in the first place.
Of course, it is recommended that once you have decided to build a oven or a fireplace in your home and need a new chimney, do not make it necessary that you have to worry yourself because of it again later on, but ask your builder to install a stainless chimney in the first place. It might be a bit more expensive than an ordinary, but in the long run it will be more beneficial and also it makes your home safer for you and your family.