Add this to a suitable place in the DefaultDemo.aspx
<h1><EPiServer:Property runat="server" PropertyName="heading" /></h1>
Thanks Henrik, One more question. When I added this property It took a long time to actually appear on the site and when I comment it out it takes a long time to disappear aswell why might this be?
I guess this is a browser caching issue. Try reloading your page with CTRL + F5 after you have modified your markup code or css.
I'd say it's probably the web server output cache and/or the JIT compiler which doesn't immediately recompile the aspx.
I want to add a heading property to to the [Demo] StartPage template which will become the h1 of the page. I have added a new property called heading to the template but what do I need to change to the DefaultDemo.aspx page? Is it necessary to add a content placeholder to the master page?