21 Degrees

UK Passivhaus Awards 2015 Large Projects Finalist. A regeneration of two dilapidated blocks of flats in one of the poorest parts of Manchester, with EnerPHit as a mechanism for creating a sustainable low carbon community.Architects Edelmann & Ebling and developer R-Gen Developments, together with Passivhaus Designer Eric Parks, have just completed an ambitious retrofit project to the EnerPHit standard at Erneley Close, Manchester, as part of Eastlands Homes’ £180 million decent homes programme. The project involved a major low energy refurbishment of 32 maisonettes (comprised of two blocks with 20 and 12 maisonettes, respectively), helping to massively improve energy performance, as well as being part of a ‘re-branding’ exercise for the area.Structural issues and the numerous thermal bridges created by balconies and walkway meant that it turned out to be an immensely challenging project. Various structural issues emerged as the project was under way, requiring the project to be continually re-modelled and re-designed in PHPP (Passive House Planning Package) along the way. The project was undertaken by contractors The Casey Group who made a great collaborative contribution to problem-solving the many challenging practical, thermal bridging and airtightness issues on the project. This included the decision to use timber frame to replace the lately-discovered structurally un-sound brick/ block work internal skin. The project greatly benefited from having an airtightness champion on site and frequent air testing throughout the build helped focus the construction team’s mind.21 Degrees designed, supplied and commissioned the MVHR systems for the project, as well as supplying GBS78 triple glazed timber windows and doors and a variety of Pro Clima airtightness products. 21° also provided extensive technical input and product support throughout the project. 21° Director Bill Butcher was also involved in giving some Passivhaus training to the building contractors before the project started on site.MVHR systems & designDesigning the MVHR systems to fit into the maisonettes initially proved challenging for the team. 21° MVHR design service worked with Passivhaus mechanical & electrical expert Alan Clarke to design a system to fit the space available. The Zehnder ComfoAir 160 unit was chosen because of its compact form and performance characteristics, which enabled it to be located on the bathroom wall behind the bath. Space for the rigid steel ductwork was located by creating a ceiling void space over the bathroom and landing. 21° and Alan Clarke carefully designed and attenuated the system to ensure that the system operates quietly and with maximum efficiency. To ensure extra quality control, 21’s MVHR Technical Manager Andrew Farr gave a toolbox talk to ventilation installers on the project and he and our team commissioned the units after installation.As a developer undertaking our first PassivHaus project it was vital we installed the most technically effective MVHR given the constraints of working within an existing building. Fortunately, we had excellent design and production specification from Alan Clarke, our retained M & E Consultant, and subsequently a fantastic on site implementation and practical assistance from Andrew Farr and his colleagues at Green Building Store. Each flat now has a great internal air quality with residents amazed at how quiet the MVHR system actually is in performance.”Phil Summers from R-Gen DevelopmentsPERFORMANCE windows & doorsThe project team specified GBS78 outward opening triple glazed timber windows (with a whole window Uw value of 0.9 W/m2K) for the project. 21° gave specialist design input into the window installation detailing. The combination of high thermal performance and good design detailing contributed to the project’s meeting strict EnerPHit requirements, during the Passive House Planning Package (PHPP) design process. To further help with installation detailing, 21° supplied its windows in pre-prepared insulated plywood boxes – as a complete installation module – to make installation easier and to help reduce thermal bridging around the window junctions.21 Degrees range suited the project for a number of reasons. It is a substantial window which is solid without being too clunky and is sufficiently robust to help us meet the EnerPHit airtightness requirements. The windows also offered a cost-effective option for the project and an alternative to high-end Passivhaus ranges. Being delivered pre-installed in insulated plywood boxes was also a massive help which simplified the installation process and reduced complications on site. In many ways, the windows delivery and installation was one of the most straightforward aspects of what was a very complex project. It was really good to have 21° input on window detailing at the very beginning of the project. We got far more input from 21° than we would get from other window suppliers and they very much worked with us as one of the team.Eric Parks and Nittai EdelmannPro Clima airtightness productsAirtightness issues with the existing building fabric meant that the project had additional airtightness challenges. For example the volume of air travelling through the party walls was far in excess of original expectations. Pro Clima airtightness products including Solitex DA membrane, Tescon No 1 and Tescon Profil airtightness tapes and Orcon F adhesive were used extensively on the project, among other airtightness strategies. The products were supplied through 21°, which also provided comprehensive technical product support , including organising Pro Clima toolbox talks. The completed project achieved 0.84 air changes @ 50Pa, successfully meeting EnerPHit criteria which requires 1.0 air changes @ 50 Pa or lower.Airtightness was the single biggest issue on the project. As the project changed from the original blockwork and wet plaster strategy to timber frame, the Pro Clima range came into its own. The Pro Clima range is great because it seems to have an answer for every problem that arises on site. We found the Tescon Profil tape was particularly flexible and useful on site as its two adhesive strips means that it works well around windows and corners.Eric Parks

Architect Lucy Mobbs from Suffolk firm Mobbs Architects has designed a low energy newbuild project for selfbuilder clients in Suffolk. The 197 m2 timber frame house aimed for high fabric efficiency and achieved high levels of airtightness.21°’s GBS98 triple glazed timber alu-clad windows and doors were chosen for the project. 21° also designed, supplied and commissioned the project’s MVHR system.DesignThe building is designed around a private courtyard as it was necessary to locate the house to the southern end of the site where overlooking was more likely. An 8m wide glazed section of wall in the kitchen/living room faces south while other parts of the house complete a courtyard to create a private and sheltered outdoor space.The construction is lightweight timber frame with wood fibre insulation and achieved 0.6 air changes per hour at 50 Pascals. The house is heated with an air source heat pump, linked to a 6kWp PV array.Triple glazed alu-clad windows and doors21°’s GBS98 triple glazed timber alu-clad inward-opening windows with a whole window U value of 0.75 W/m2K were chosen for the project. A shaped Apex window was also selected.The aluminium-cladding was finished in RAL 9005 while the internal timber finish was RAL 7021 on the inside.A Contemporary door (BL02) was specified with a sidelight, as well as two Lift & Slide doors and some fully-glazed entrance doors.We chose 21° GBS98 windows because of the thermal performance. The aluminium-clad frames added aesthetic value and worked well with both the zinc and rendered wall finishes. We had great support from 21° during the detailed design stage.Lucy Mobbs - Architect

An integral part of any home, windows play a huge role in energy efficiency, comfort, and aesthetics. In this project, the client sought to replace their old, deteriorating windows and doors with high-performance alternatives. Here's how we approached the challenge and delivered results that exceeded expectations.The challengeThe client's primary goal was to replace their old wooden double-glazed windows, which were no longer fit for purpose. The windows and doors were not only warped and rotten but also varied in their level of glazing, leading to significant drafts and water ingress. The client's specific energy-efficiency goals were to eliminate these drafts and prevent rain from seeping through the frames, creating a warmer and more comfortable living environment.Our solutionUnderstanding the urgency and importance of the project, we began by inviting the client to our main showroom. This visit allowed them to explore our range of high-quality windows and doors and select the most suitable products for their home. After careful consideration, the client opted for our GBS78 timber outward-opening windows, complemented by GBS78 double and single doors. For the bedroom, we supplied a GBS78 inward-opening floating mullion tilt and turn window, showcasing our ability to provide diverse product types for different areas of the home. The chosen colours – RAL 9010 for the interior, RAL 7044 for the exterior, and RAL 6012 green for the front door – added a modern touch to the property’s appearance.One of the major challenges during the implementation phase was removing the old windows. Existing timber windows can often be hard to remove when the internal plasterwork needs to remain intact. However, our team are experienced in handling such situations and have all the correct tools to ensure minimal disruption to internal walls when removing awkward existing frames. This ensured that the removal process was efficient and minimally disruptive.The outcomeThe installation of the new windows and doors resulted in significant improvements in both energy efficiency and the overall performance of the home. The house is now noticeably warmer and quieter, with the new triple-glazed units providing superior insulation compared to the previous double-glazed windows. The updated exterior colours also contributed to a fresh, modern look, significantly enhancing the property's curb appeal.Once we decided to replace all our windows and doors, 21 Degrees made the whole process really simple, with their in-house team installing everything with a high-level of professionalism. All in all, we couldn’t have made a better decision!Homeowner

The Hen House project is an award-winning energy efficient newbuild house, built into a steeply sloping Sheffield garden site, designed by Paul Testa Architects and built by Simplicity Construction for selfbuilder clients Jo and Gail. The house has been designed to be extremely warm and comfortable to live in whilst using very little energy compared to a typical new-build house.21°supplied the triple glazed windows & doors and MVHR system for the project.DesignThe house was built using Passivhaus principles, and was designed using PHPP, with a total space heating need of 36 kWh/m2 per year and a construction cost of £1975/m2The two storey dwelling was carefully fitted into its difficult plot whilst maximising the views to the West, avoiding numerous mature trees or overlooking other properties.The home is accessed on the upper level, which offers a spacious, light filled kitchen, living and dining space, made from a highly insulated timber-frame superstructure provided by Frame Technologies. The long room is divided by a full-height plywood bookshelf which maintains views through to the large balcony overhanging the slope at the far end. This upper level is clad in timber shingles which will soften with age and blend the house into its wooded surroundings. The lower floor houses the bedrooms and support spaces in a solid, masonry plinth.We specified the GBS78 range because of its excellent value for performance and also because of the quality of 21°’s customer service. Value for money is obviously an important factor when specifying. We did some cost comparisons and these windows came out really well compared to competitors. 21° is also very easy to work with and really supports us throughout the whole specification process. We have specified 21°’s GBS78 range on a number of projects, including for the EnerPHit radical retrofit of my own home, which is currently on site.Paul TestaTriple glazed timber windows & doors21°’s triple glazed timber windows and doors were chosen for the project. The window and door specification for the site included a large gable end with French doors and triangular fanlights, as well as long narrow windows positioned to fit in with ‘overlooking’ issues and also to take advantage of the views of wooded overgrowthProducts supplied from the GBS78 range included: Tilt and turn windows, two Lift and slide doors, an entrance door and sidelights and a large triangular fixed panel. The windows and doors were finished with a clear stain inside, and opaque paint finish (RAL 7037) outside.Thank you. We couldn’t be more impressed with the service we’ve had throughout from 21°. You’ve been absolute professionals, really easy to deal with and all-round lovely folk!Clients Jo and GailMVHR mechanical ventilation with heat recovery21° designed, supplied and commissioned the MVHR (mechanical ventilation with heat recovery) system, which included a PAUL Novus 300 MVHR unit and a rigid spiral wound steel ducting system, which was incorporated into the contemporary design of the project, rather than concealed.It was good to work with 21° on the MVHR system for the project as a tried and trusted supplier of ventilation with heat recovery systems. The MVHR system is working really well and is virtually silent in operation, as we’d expect from 21°s MVHR design team.Paul Testa

Our clients sought to transform the derelict barns into a Passivhaus home that’s manageable in scale and cost-effective to operate. Their vision included a sustainable living space, a workspace, and a vegetable plot merging with the wildflower meadows and countryside beyond. The energy-efficiency goal was to create a high-performing home that minimises environmental impact, meeting the stringent requirements of Passivhaus certification. The initial state of the buildings posed a significant challenge, with the barns in a severe state of disrepair, one reduced to a ruin with only rudimentary wall structures standing.

An oak frame newbuild 3-bed home was designed by oak frame specialists Oakwrights and built by Furber Young Developments for clients Andrew and Linda Burnett in rural Worcestershire. The project has achieved Passivhaus certification and is due to open in the summer of 2021 as a B&B, offering visitors a unique chance to experience living in a Passivhaus first hand.21° designed and supplied the MVHR system and triple glazed timber windows and doors for the project.DesignThe clients were keen on the character and aesthetics of exposed oak timber frame and during their research phase talking to Oakwrights they became aware of the Passivhaus low energy standard. The Burnetts visited other Oakwright oak frame Passivhaus projects, which confirmed their decision to opt for the comfort and energy saving benefits of Passivhaus. After much searching, the Burnetts found a plot for their selfbuild within an Area of Outstanding Natural Beauty near Malvern in Worcestershire.Oakwright’s Passivhaus design team worked with the Burnetts to meet their aesthetic as well as low energy requirements. The house has two south-facing gable ends with four strategically positioned lift and slide doors to take advantage of the beautiful views. Balconies and shading strategies help manage any overheating risk and the balconies on the upper floors are open-roofed but with optional blinds which provide shading when needed. The house is designed ‘upside-down’ with the B&B bedrooms on the ground floor and living area upstairs to make the most of the views.To achieve the Passivhaus standard the oak frame was encased with Oakwrights’ WrightWall and WrightRoof Natural encapsulation panels, which offers high levels of airtightness. To meet the minimal heating requirements of the Passivhaus standard the commonly-seen gabled ceilings of an oak frame house needed to be truncated a little to achieve a suitable internal volume. However, the Oakwrights design still provides high ceilings, a sense of openness (especially in the double-height hall) and the enormous number of exposed oak beams provides interest and focal points creating a unique aesthetic. The project achieved 0.57 ach / hour @ 50 Pa and has a certified space heating need of 13 kWh/m2/ year.MVHR heat recovery ventilation21° worked with the Oakwright’s team to develop an MVHR system that would work alongside the encapsulation system. A Zehnder ComfoAir Q MVHR unit with rigid steel ducting was specified for the project.We have been really impressed with the windows and doors and the customer service we received from 21°. The quality of these products and the precise installation was crucial for the airtightness of the project ultimately contributing to our Passivhaus certification. 21° worked closely with Oakwrights and the builder Furber Young Developments on the design and installation of the windows. 21° was very helpful in calculating the optimal position for the windows within the Oakwrights’ WrightWall and WrightRoof Natural encapsulation panels from a thermal bridging and airtightness perspective. We also appreciated the fact the 21° could fit the windows and doors and not just supply them. Proper installation is vital to fully exploit the advantages of triple glazing.Andrew & LindaTriple glazed timber windows & doors21°’s GBS98 triple glazed timber windows and doors, including four Lift & Slide doors, were chosen for the project.One of the main reasons we chose to use 21° for our windows, doors and the MVHR system was their Passivhaus expertise and knowledge, which has been a great help and support throughout our Passivhaus selfbuildAndrew & LindaVisit WoodlandsWoodlands is the UK’s first oak frame certified Passivhaus B&B and will be opening for visitors from early July 2021.