MVC 4 - how do I pass model data to a partial view?

Also, this could make it works:

@{
Html.RenderPartial("your view", your_model, ViewData);
}

or

@{
Html.RenderPartial("your view", your_model);
}

For more information on RenderPartial and similar HTML helpers in MVC see this popular StackOverflow thread

You're not actually passing the model to the Partial, you're passing a new ViewDataDictionary<LetLord.Models.Tenant>(). Try this:

@model LetLord.Models.Tenant
<div class="row-fluid">
    <div class="span4 well-border">
         @Html.Partial("~/Views/Tenants/_TenantDetailsPartial.cshtml", Model)
    </div>
</div>