The form factor

Apeer’s Lumi window and door range has demonstrated that you can step outside the design box and produce glazed products that are good to look at and not just through, according to MD Asa McGillian, while performing brilliantly.

Regulations and customer expectations require windows and doors to perform to minimal levels, and the more expensive and avant-garde they may be, the more is expected of them in terms of security and thermal performance.

When we designed Lumi, we wanted it to appeal aesthetically, but also deliver the kind of energy efficiency home owners expect from a premium product. Yes, it looks fantastic, but every component has been designed from scratch to offer great performance as well as looks. Therefore, homeowners can enjoy an aspirational, high value product without having to compromise on its performance.

Unlike a traditional window, the glass in a Lumi product is structurally bonded to a core of high strength, pultruded glass reinforced plastic (GRP) profiles. This has resulted in a window and door system that is not only cool, but it has produced a product range that boasts market leading strength, security and energy efficiency as well.

In the early days of Lumi, many of our installations were in higher value properties where the homeowners were thinking very much about the style of their properties first. While the cost of energy was not such as issue, the overall performance was.

Lumi is increasingly specified for homes in which energy efficiency is important to reduce energy bills and the impact of on the environment.

The driver from concept has been the attainment of standards laid down by Passivhaus. Although projects built to Passivhaus standards remain quite rare (with only around 30,000 built worldwide), it presented a goal to achieve with our windows and doors, which we have reached or exceeded.

Our windows perform to 0.8W/m2K, with doors (dependent upon style) 0.6W/m2K. We achieve this through argon-filled, 50mm triple glazed units, using low-e glass and a warm edge spacer bar, all produced in our own factory. The frames are also double rebated and foam insulated.

We’ve used warm edge in our units for over a decade now because it’s easy to work with and 100% reliable, and we know that it plays a key role in making our windows as energy efficient as possible.

Behind the flush glazing is a twin seal, double rebated frame, which means it combines a flush finish effect on the outside with a stormproof construction, and that’s something that other flush effect windows have been unable to achieve.

Part of the reason for our success with Lumi, is that when we designed it, we were able to do so with a clean slate. We started out manufacturing doors, so for our first window we weren’t limited by trying to adapt or evolve an existing system – we could start from scratch with new ideas and just concentrate entirely on making it absolutely the best we could.