server/res/e3a/buildings.xml

<?xml version="1.0"?>
<buildings xmlns:xi="http://www.w3.org/2001/XInclude">

  <xi:include href="config://default/buildings/castle-2.xml" />

  <building name="watch" capacity="1" maxsize="10">
    <function name="name" value="fort_name"/>
    <function name="protection" value="building_protection"/>
    <function name="taxes" value="lua_building_taxes"/>
    <construction skill="building" minskill="1" maxsize="5" reqsize="1" defense_bonus="0">
      <requirement type="log" quantity="1"/>
    </construction>
	  <construction skill="building" minskill="2" maxsize="5" reqsize="1" defense_bonus="1">
		  <requirement type="log" quantity="1"/>
	  </construction>
	  <construction skill="building" minskill="2" reqsize="1" defense_bonus="2">
		  <requirement type="log" quantity="1"/>
	  </construction>
  </building>

  <building name="market" capacity="1" maxsize="10">
    <maintenance type="money" amount="200" vital="yes"/>
    <construction skill="building" minskill="3" reqsize="1">
      <requirement type="log" quantity="1"/>
      <requirement type="stone" quantity="1"/>
    </construction>
  </building>

</buildings>