Before you can install solar panels on a flat roof, you will need to get permission from the Fire Department or the Department of Buildings. The Fire Department must grant you special permission to deviate from fire code, so you need to apply for a variance. You can file your application on paper for the moment, but you will be able to file electronically by the end 2019.
Plan before installing
If you're considering installing solar panels for your flat roof, make sure you plan ahead. You'll want to make sure your solar panels fit properly and leave room for ventilation. They should not interfere with normal roof functions. The best racking system maximizes the amount you receive from solar panels.
There are two main methods to install solar panels for flat roofs. You can either mount them directly into the roof, or use a ballasted system that secures them with weights. You can also use hybrid systems that combine both of these methods.
Pay attention to wind speed
For flat roof solar panels, wind speed should be considered. Solar panel installations can suffer from poor performance if they are subject to high wind speeds. Consider increasing the thicknesses of the racking systems you use to install solar panels in high wind areas.
You need to know the direction and speed of the prevailing wind in order to calculate the wind speed. ASCE 7-16 figure 29.3-1 provides the prevailing wind speed direction for buildings that have a flat roof. You can calculate the weight of your panels and the amount you will generate electricity by using this information.
Consider tilted mounting system
For flat roofs, you might consider a tilted mount system for your solar panel. Your solar panels will produce more energy if they are tilted correctly. Once installed, the tilt can also be adjusted. Warranty companies may not cover solar panels with less tilt than 2 degrees.
Another consideration is whether trees will shade the solar panels, which can lower the energy output. A flat roof is better if there aren't any trees blocking the sunlight. Additionally, a flat roof is visually more pleasing than one with an angled roof.
Get planning permission
Before you begin installing solar panels on your flat roof, you should first contact the planning office in your area. This office can tell you if you need planning permission and provide guidance on how to go about applying for permission. The decision will usually be made within eight weeks after the application is submitted. If the planning officer finds that your proposals will create a problem in the area, they may refuse to approve your application. If this happens you can appeal the decision and consult a reputable company that will assist you.
You can start the solar panel installation once you have obtained planning permission. This process is identical to solar panels installed on pitched roofs. However, you will need to comply with local planning laws before you begin work. This will ensure that you don't cause any problems for the council or your neighbours.