This year Bow Tie Construction, based in High Wycombe on the outskirts of London, snagged a prestigious award for “Retrofit Installer of the Year” from the Retrofit Academy, a leading trainer and qualifier of retrofit professionals in the United Kingdom. Founded in 2011, Bow Tie Construction is a residential contracting firm with roughly 40 employees that works exclusively on low to zero operational carbon retrofits and new-builds, using Passive House and Energiesprong principles. The award was given to Bow Tie in recognition of its demonstrated excellence and its work to develop approaches that can be scaled up while retaining a strong focus on residents’ experiences. The Retrofit Academy trains and qualifies retrofit professionals, including retrofit coordinators, a required position for retrofits that receive public funding.
Bow Tie Construction has been working to industrialize and optimize many aspects of the deep energy retrofit process, with a goal to cut in half the costs of delivering these retrofits by 2025. One of its newest innovations is known as the YESporch, a pod that houses all the mechanical systems that a retrofitted unit needs: a heat recovery ventilation system, an air source heat pump for space conditioning, a hot water tank, and a custom-designed manifold. The pod is designed to be installed on the exterior both because many existing homes lack the space for new mechanical equipment and to allow for easy maintenance access. The self-contained unit can be installed and commissioned in three days, minimizing occupant disruption and allowing for a swift transition from gas to electricity. Bow Tie is piloting its YESporches at six 65-m2 homes that it is retrofitting in Sutton, South London.
Bow Tie is similarly taking aim at the other major retrofit component: insulated panels suitable for retrofits; a patent is pending for the panelized insulation design and installation method the company has developed for renovating apartment buildings. A prime feature of the system is its innovative approach to optimizing the fit of these panels on the buildings. Hagop Heath-Matossian, interim managing director at Bow Tie Construction, points out that too often prefabricated panels arrive on a construction site and don’t match the building’s dimensions well enough, creating delays as the crew work to modify them on site. “We created a system of physical guides that attach to the building during the design stage and stay there until construction is completed, and the panels are designed to fit these guides rather than the building,” he notes.
In addition to these technical fixes, Bow Tie is perfecting the art of remodel communications generally and resident engagement in particular. “The main challenge in a deep energy retrofit of social housing is convincing the residents, as most don’t understand what it is. A lot of it seems like a big bother, and unnecessary, to residents,” Heath-Matossian explains. Bow Tie’s approach to occupant engagement was fully evident at its Innovate UK-funded project BowTieSprong Treadgold House, where its co-design process resulted in 24 out of 25 residents voting in favor of an Energiesprong retrofit there. With support from Permaculture designers, Bow Tie led workshops for the residents to solicit design ideas for the houses and garden spaces, which were underused. The resulting conceptual design doubled balcony sizes for the units above the ground floor, while minimizing thermal bridging at the balcony connections, and created a glazed winter garden for ground-floor residents. In its design Bow Tie also made sure to include improvements to the gardens to foster food growing, seed propagation, and other group activities that build resident interactions.
Heath-Matossian joined Bow Tie five years ago because he was extremely excited by the opportunity to deliver Passive House and Energiesprong-style builds in the London area. The firm has grown to include a five strong in-house design team, Passive House designers, and a certified Passive House tradesperson. Bow Tie is the leading Passive House builder in the London area, Heath-Matossian says. Its deep expertise in low-energy retrofits is allowing it to lead an impressive number of upcoming Energiesprong renovations of Council-owned housing—eight at last count, with a further nine in the design stage. Given the climate crisis, Heath-Matossian is working full tilt to optimize his firm’s processes and deliver on as many deep energy retrofits as his teams can.
