High energy costs: is your commercial roof an untapped asset?

With energy costs continuing to put pressure on operating margins, businesses are looking more closely at where efficiencies can be made. For owners and occupiers of warehouses, factories, distribution centres and offices, part of the answer could be directly above them.

 

Commercial roofs often represent a significant untapped asset. Solar installations can generate renewable electricity on-site, reducing reliance on imported energy and helping businesses manage future price volatility. For organisations with substantial daytime electricity demand, rooftop solar can also help align energy generation with consumption, improving the financial benefits of an installation.

 

For many businesses, however, the potential planning implications can create uncertainty and delay investment decisions.

 

One of the most common misconceptions is that rooftop solar schemes exceeding 50kW require a full planning application. In reality, 50kW is not the maximum capacity permitted under permitted development rights. Instead, it is the threshold at which prior approval may be required.

 

Under Class J of the General Permitted Development Order, rooftop solar installations of up to 50kW can generally proceed without prior approval, subject to meeting the relevant criteria. Importantly, larger systems can also benefit from permitted development rights. The previous 1MW capacity cap was removed in December 2023, opening the door to significantly larger rooftop installations.

 

This change is particularly relevant for larger commercial buildings. Warehouses, logistics facilities and industrial premises often have extensive roof areas capable of accommodating solar arrays far in excess of 50kW, meaning businesses may have more opportunities than they realise to generate renewable energy without the need for a full planning application.

 

Where installations exceed 50kW, the prior approval process focuses on matters such as design and external appearance, including the potential impact of glare on neighbouring occupiers and the surrounding area. Restrictions also apply in relation to panel projection, building height and setbacks from roof edges, whilst different considerations can apply to listed buildings and sites within designated areas.

 

Understanding these requirements at an early stage can help businesses avoid unnecessary delays and ensure that potential constraints are identified before investment decisions are made. In many cases, obtaining planning advice early can provide clarity on whether permitted development rights are available and what level of supporting information may be required.

 

Matthew Garvey, Planning Director at DHA and specialist in permitted development rights, comments:

 

"With businesses scrutinising energy expenditure more closely than ever, commercial rooftops deserve greater attention. For premises with substantial daytime electricity demand, solar installations can make a meaningful contribution towards reducing operating costs and improving long-term resilience.

 

The 50kW threshold is often misunderstood. Many businesses assume larger schemes automatically require planning permission, when in reality permitted development rights may still be available. Taking advice at an early stage can help businesses understand what is achievable, identify any potential constraints and move forward with confidence."

 

At DHA, we see rooftop solar as an opportunity not only to generate renewable energy, but to make existing commercial buildings work harder. By considering planning requirements at the outset, businesses can better understand the options available to them, avoid unnecessary delays and unlock the value of underused roof space. At a time when organisations are seeking ways to improve efficiency, resilience and sustainability, commercial rooftops may represent one of the most overlooked assets they already own.