Hard coded
<a href="{low_search:url search:property_type="House"}">
<label><input type="checkbox" name="House" value="House">House</label></a>

<a href="{low_search:url search:property_type="Apartment"}">
<label><input type="checkbox" name="Apartment" value="House">Apartment</label></a>

<a href="{low_search:url search:property_type="Land"}">
<label><input type="checkbox" name="Land" value="Apartment">Land</label></a>


Low List
{exp:low_list:each items="House|Apartment|Land" as="propertytype"}
<a href="{low_search:url search:property_type="={propertytype}"}">
<label>
<input type="checkbox" name="{propertytype}" value="{propertytype}">{propertytype}
</label></a>
{/exp:low_list:each}


Low Options
{exp:low_options:property_type}
  {if option:group != ''}
<optgroup label="{option:group}">{/if}
{options}
<a href="{low_search:url search:property_type="={option:value}"}">
<label>
<input type="checkbox" name="{option:value}" value="{option:value}">
{option:label}
</label>
</a>
{/options}
{if option:group != ''}</optgroup>{/if}
{/exp:low_options:property_type}