Property of domain class not recognized in GSP file for a Grails project

I have few domain class in my project and everyone of those works perfectly except one. New to web development so I might have done something wrong. This is what my domain class looks like:

I am trying to create a table to show contents of this ORM with the code below in a GSP file:`

<table class="table table-striped table-bordered table-hover">
    <thead>
       <tr>
           <th scope="col">Building</th>
           <th scope="col">Supervisor</th>
           <th scope="col">Title</th>
           <th scope="col">Email</th>
           <th scope="col">Phone</th>
        </tr>
     </thead>
     <tbody>
        <g:each in="${Supervisor}" var="supervisor" status="i">
            <tr>
                <th scope="row">${i}</th>
                <td>${supervisor?.building}</td>
                <td>${supervisor?.name}</td>
                <td>${supervisor?.title}</td>
                <td>${supervisor?.email}</td>
                <td>${supervisor?.phone}</td>
            </tr>
         </g:each>
     </tbody>
</table>

I am getting error " No such property: building for class: myFolder.Supervisor"