There isn't a built-in rewards system on Spacehive; we prefer to promote the project as the reason to back a project. However it's possible to offer rewards using the text space available on the project page.
Spacehive does not offer an in-built system to offer rewards. As all Spacehive projects are about improving the local area, we believe that getting that newly renovated playground, the community hub, or saving a historic building is the biggest reward available. Our research backs this up; people who pledge to projects are overwhelmingly local, and therefore primarily driven by a sense of wanting to see positive change in their area.
We also believe that for project creators, devising a system of rewards (and then having to fulfill them) can be costly, time-consuming, and most of all detract from the focus required to deliver the project they are campaigning for.
If there is a reward that you are set on offering to backers, you have the text body of your project page, as well as the project update tool to display and communicate this.