The energy efficiency of a building is a key consideration for house builders and homeowners, both in terms of its effect on the environment, on-going running costs, and future saleability. This efficiency is calculated according to a series of measures, such as a U Value which indicates how well or poorly heat is lost, which when combined provide an overall energy performance rating.

Paul Oldham, Technical Manager at Stormking, a UK-based manufacturer of Glass Reinforced Plastic (GRP) building components, looks at the impact the U Value has on product development and manufacture, and how Stormking’s approach is enabling it to keep in line with the ever more rigorous ratings being imposed by building regulators:

“Each element of a new building, for example a roof or a wall, will have a U Value. This value is a measurement of how well the element will transmit heat from inside to out. Taking the thermal resistance of each component of an element, such as brick, block, insulation, glass, or tiles, and combining it with their thicknesses and the multitude of routes through which heat can pass, we are able to give an overall U Value for that element.

“Here at Stormking, we have been manufacturing components designed to meet these regulations for over 30 years and have developed products for more exacting standards, such as our WarmaDorma© dormer window, for over ten years. When our WarmaDorma© was first devised, it more than met the U Value regulations of the time. However, over the intervening years these regulations have become more stringent and as such all building components have had to progress to remain in line.

“It was apparent, even ten years ago, that regulations would become tighter. This is why our WarmaDorma© was specifically designed to meet the gradual increase in thermal performance required for dormers. This innovative design has resulted in us being able to increase the thermal benefits of our dormer windows with minimal change to our production methods.

“In addition to the thermal benefits of our GRP dormers, we have also considered how junctions

– for example where a wall meets another wall or roof, or a window meets a wall – perform with regards to heat efficiency. Traditionally in GRP dormer construction, a structural timber frame on which the internal finishes would be fixed, was fitted directly to the inside of a GRP outer shell. Although initially strong and secure, heat could easily pass from inside to out, through the internal finish, timber frame and GRP outer layer. In response, Stormking has developed a method whereby this timber frame is separated from the GRP by a layer of insulation, which greatly improves heat retention but without compromising strength and stability.

“This is just one example of how seriously we take product development with regards to heat efficiency. Our aim is to produce components which not only meet the legislative requirements, but exceed them, providing the construction industry with future-proofed products that are designed to adjust to changing rules and regulations.

“We pride ourselves on our commitment to innovation and will continue to create high quality GRP components to help the industry navigate ever-changing building regulations.”

Further information about Stormking and its range of GRP building components can be found at or by calling 01827 311 100.