Exaco does not provide structural certification for special order/custom greenhouses. Janssens’ greenhouses are strong – but if you need a structural certification or are applying for a permit you should do this before ordering the greenhouse. Depending on your location and local code requirements you may need to add additional supports/reinforcements to your kit and this will be best ordered with the greenhouse. Within the special order category they range widely in size, anchoring, upgrades and supports added so there is not a “one size fits all” certification that can apply. Exaco can provide the certifications for a fee or direct you toward an engineer that can assist you with the documentation you need. Keep in mind, each location/state has different load requirements. If you are in a location that has higher load regulations, you may need to purchase additional reinforcements.