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Tag: Passivhaus Homes

  • HPH266 : How to invest sweat equity into a project while maintaining quality – with Ajay Boardman and Nigel Bowley

    HPH266 : How to invest sweat equity into a project while maintaining quality – with Ajay Boardman and Nigel Bowley

    Client Ajay Boardman and her builder/carpenter Nigel Bowley share their experience of working together on her self build project. In addition to project managing Ajay is labouring for Nigel. We look at why this relationship has worked well and consider how much money she is saving.

    Interview with Ajay Boardman and Nigel Bowley

    Ajay is building a 260m² Passivhaus in the South Downs National Park, using the PH15 build system. Having found Nigel Bowley to build the timber frame, it seemed natural that, being a practical person who didn’t have a job at the time, Ajay herself would take on the role of project manager and labourer.

    Parental support has been invaluable

    A big factor in Ajay being able to take on the project has been the support of her parents who live on a farm next to her and the site. Having plenty of experience helping her dad out with manual work on the farm has stood her in good stead for transferring her skills to the building project.

    Not only has her dad helped out with the labouring when she has needed a break or to concentrate on the project management side, but he also always has the right tools for the job. In addition, Ajay’s mum helping out with childcare has meant that Ajay has been able to put in the extra hours while still having the children close by.

    Nigel and Ajay quickly realised they would have a good working relationship

    A carpenter by trade since joining a YTS scheme in 1986, Nigel has had a varied career working on projects such as house building, extensions, internal renovations, roofing and some commercial work. He is equally used to working on his own or having a small number of sub-contractors and labourers alongside.

    From previous experience of working with labourers, Nigel had his doubts about how successful having Ajay and her dad work with him would be. However, Ajay soon demonstrated that she had a great interest in the building, listened, followed instructions and had good manual coordination and skills.

    Working on a weekly payment basis rather than a contract, Nigel had the ability to walk away if he needed to, but after a successful first week levelling the site they both realised they would be able to work together well.

    They also found that their different skills complemented each other well. Where Ajay’s knowledge of the parts and the process was lacking, her admin and communication skills helped take what was in Nigel’s head and translate it into something that she could work from.

    Breaking the jobs down makes the whole process less overwhelming

    Nigel explains that looking at the entire job and thinking about what needs doing can actually be pretty overwhelming. He tries to keep things more simple by breaking each job down into smaller parts. That way the focus only ever has to be on those few things that are needed over a short time span.

    Doing it yourself gives you control over the quality

    Having been to see a different PH15 house, Nigel was confident about the timber frame aspect and getting it level on the slab. Moving forward they may get an electrician and possibly a decorator in, but the rest of the work they are keen to do themselves. This includes the MVHR and all the taping and joining because they are so aware of the importance of getting it right for the airtightness.

    Ajay and Nigel have found a happy balance in what they each need to control based on their individual skills, without controlling each other. While Nigel is in control of the job, he’s also answerable to Ajay’s quality control. This method has worked for them and hasn’t caused any conflict.

    Nigel’s tips for anyone else in a similar situation would be around communication: listening to each other and knowing your boundaries on what to say and when.

    Quality hasn’t been compromised by the cost savings

    Taking on the role of labourer and project manager has obviously been a cost saving for Ajay, and by taking jobs like sweeping up and placing orders away from Nigel, it means his time can be spent more productively.

    Having a relative novice alongside and working out things like the airtightness has meant that the speed of work has sometimes been slower than on his other jobs. However the quality hasn’t been compromised, with architect and co-creator of the PH15 system, Jae Cotterell, crediting the workmanship being of very high quality and better than a lot of professionals.

    It’s physically very demanding

    Nigel believes that sweat equity can work whether it is a PH15, masonry or other build system.

    “I don’t think it matters on the style or the type of building. It’s just really if you’re prepared to work, properly work. Because I don’t think a lot of people really work that hard when it comes to physical.”

    But doing it themselves has allowed an element of flexibility when it comes to working hours and fitting in around school runs and other responsibilities.

    They are not working to a programme

    Nigel is used to working to a programme, so not having one on this project has been one of the hardest things for him to adjust to. He is used to setting an ambitious timeline in order to keep the labourers motivated.

    “On previous jobs, you can burn your labourers up quite quickly and they become unmotivated and they leave pretty quick. So, you’ve got to really manage their physical abilities, your own physical abilities, and so you kind of have to let the job lead you in that way really. And knowing when that is going to be a physical effort, a mental effort, a slow part of the job.”

    It’s more about the process than the end result

    With a few months left on the project, Ajay is relaxed about how the house will turn out. For her, the greatest satisfaction is the process of making it, though the air quality and comfort that comes with it being a Passivhaus is something she is particularly looking forward to.

    Passivhaus Workshop

    If you’re new to Passivhaus and want to find out more about it, then check out the National Self Build and Renovation Centre in Swindon which is running regular workshops. There will be explanations of the key principles along with case studies and demonstrations.

    Find out more

    Visit the website of Nigel’s South Downs Eco Homes

    Find Nigel on Facebook

    Read more about the PH15 build system

    Transcript

    Download a transcript of the interview with Ajay Boardman and Nigel Bowley

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    Subscribe, rate and review us on Apple Podcasts

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    Follow Ben Adam-Smith on Bluesky

  • HPH183 : How to achieve an outstanding airtightness result

    HPH183 : How to achieve an outstanding airtightness result

    Buckinghamshire Passivhaus has become one of the most airtight buildings in the UK. As such, we consider what factors contributed towards their exceptional result of 0.08 air changes per hour at 50 Pascals.

    In this podcast we hear from key team members involved in the construction on this energy-efficient home.

    Buckinghamshire Passivhaus timber frame

    Following a PH15 build

    As luck would have it, this is actually our second in-depth video case study for The Hub (the first being Long Barrow).

    I’d got to know Janet Cotterell, author of The Passivhaus Handbook, quite well and been intrigued by the development of the PH15 system.

    So since autumn 2016 every week or so we have been filming progress on site. Now the building is watertight and ready for its preliminary airtightness test.

    The PH15 system aims to make Passivhaus affordable for everyone

    The Passivhaus Homes PH15 system has been developed over time to address many of the challenges of achieving Passivhaus standard.

    The system is manufactured off-site and delivered in packs as needed. With good carpentry skills, it is easy to assemble.

    We spoke to Janet about it in episode 121 – the pros and cons of building with a kit or system.

     

    A team effort helped them achieve an exceptional result

    It’s one thing using a ‘Passivhaus’ system to meet the standard, but an outstanding result like this is only possible with a team effort.

    At the heart of this is the relationship between client, architect and contractor.

    There also needs to be buy in from everyone on the team.

     

    Carpenter Wayne was determined to get an airtightness result of 0!

    Not satisfied with merely meeting the Passivhaus criteria, foreman Wayne Kempster from Jigsaw Construction set himself the ambitious target of achieving 0 air changes per hour at 50 Pascal!

    Despite being impossible Wayne wouldn’t aim for anything else.

    And let’s remember this is Wayne’s first ever attempt to build a Passivhaus.

     

    Air leakage expert Paul Jennings’ best ever result

    With 30 years of experience, Paul knows a thing or two about airtightness. In fact he was the key contributor for the House Planning Help documentary The Future of Housing.

    At Buckinghamshire Passivhaus he recorded a reading of 0.087 air changes per hour at 50 Pascals, his career best.

    Paul points to the PH15 system as well as the team for achieving this result. “Fundamentally it’s a very airtight system. You’ve got airtight boards, good tapes and quality control of people doing the works.”

     

    Simple detailing increases the likelihood of a good result

    Janet says: “If the detailing is complicated, however good the builder is, they’re going to struggle.”

    When it comes to sustainability it’s amazing how often simplicity comes into play.

    The PH15 system is designed in such a way that the airtightness layer is always easily identifiable.

     

    Training before construction is vital preparation

    Janet stresses that proper contractor training is essential in this process.

    While it doesn’t have to be a long session, it’s extremely valuable to see how the system comes together.

     

    The concrete basement contributes to this level of airtightness

    Glatthaar is one of the few basement companies to guarantee Passivhaus performance.

    Paul says: “Having the basement helps because you’ve got a concrete box which is going to be airtight, and it adds to the volume.”

    In episode 163 Andrew McInulty helped us understand what makes an effective basement.

     

    Everything coming together is the only way to get below 0.1

    Buckinghamshire Passivhaus has a simple form and is built with a simple system. Exceptional care has been taken during the construction. There’s a strong team with a lot of experience between them.

    Overall, everything has come together.

    Find out more

    Passivhaus Homes

    Jigsaw Construction

    Glatthaar

    Ready Made Basements

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  • HPH151 : When does it make sense to demolish and rebuild? – with Janet Cotterell

    HPH151 : When does it make sense to demolish and rebuild? – with Janet Cotterell

    Architect Janet Cotterell explains why her Buckinghamshire Passivhaus clients changed their minds about refurbishing, and have instead opted to demolish and rebuild.

    Janet Cotterell

     

    Interview with Janet Cotterell

    We spoke with Janet in podcast episode 121 about the kit and system methods of building a Passivhaus. One of her latest projects, Buckinghamshire Passivhaus, uses the PH15 system that she has been developing, and we are following its progress in The Hub. We have taken the opportunity to find out more about the scheme and understand why her clients have decided to knock down the house that they had originally intended to refurbish, and instead build from scratch.

     

    It was originally intended to refurbish the existing dwelling to Passivhaus standard

    Janet explains that the existing dwelling is not particularly attractive, but it is on a very attractive site of around an acre. Her clients originally wanted to retrofit the property to the full Passivhaus standard, so this formed the basis of the first scheme that Janet produced. This initial study looked at how they could adapt it and give them the accommodation that they required. While the accommodation element worked for them, they realised that the complexities of dealing with the existing fabric meant that costs could be better controlled and without the need to make any compromises if they decided to build a new house instead.

    house-front

    dsc_0047

    “And there is always the issue about replacing a house that isn’t at totally the end of its life, but my feeling is it’s so invasive doing a retrofit in any case that the fact that you are then replacing it and building something that will last for a very, very long time, my own position is that generally I would go for replacement dwelling unless there was some particular architectural reason.”

    Another contributing factor in the decision was that being a new build they would be able to claim back the 20% VAT – a considerable economic benefit over a refurbishment.

    proposed-house-elevationsjpg_page1
    Proposed elevations

     

    The brief gave the architect plenty of flexibility in designing the outside spaces

    While the clients had firm ideas about the accommodation they wanted inside the house, they were happy to leave much of the aesthetics and external design to Janet. She has focussed on maximising the best features of the plot by making the most of the sun and the beautiful views. The house will be built in the centre of the plot to maximise the views, and divide the space up to create different sections which will each be treated slightly differently. The design incorporates a long brick wall leading to the house which creates the separation of public and private spaces, and will give a courtyard type feel.

    The external finishes of the house are determined largely by the local council design guide, but Janet was also happy to take on the challenge of creating a Passivhaus which still has the look of a traditional UK home.

    Basement Plan
    Basement Plan

    Ground floor plan
    Ground floor plan

    First floor plan
    First floor plan

    The Passivhaus construction system being used should help bring Passivhaus to more affordable levels

    The aim of Passivhaus Homes is to create a timber frame, Passivhaus compliant, solution, with details that can be passed on to other people. They have created a package of details which they have been tweaking as they go, and believe they are now at the point where most of it is working successfully. Their intention is that if you were to use their timber frame system, and built it in a certain way, the thermal bridge details would already be proved to work. By making this simplification and having standard details already done, it should save considerable money for the client.

     

    The timber frame will arrive as a puzzle of pieces!

    The pieces are being cut off-site by Passivhaus Homes and then delivered to be assembled by contractors at the plot. For Buckinghamshire Passivhaus there are likely to be around 500-600 pieces. The cutting machine they use is able to work out the most economical way of cutting all the pieces with the least amount of waste possible.

    Buckinghamshire Passivhaus timber frame
    Buckinghamshire Passivhaus timber frame – the timber portal frame design with ply plates inserted at eaves and ridge to join the different I-joists together

     

    However, rather than delivering a pile of pieces in one go, they also need to work out a system of delivering them to the builder so they can be unpacked in an order which will make sense, and only need to be unpacked when required. While this does end up creating a little more waste, it is still considerably less than the amount that would usually be generated on site. And with the waste being created at the factory, they are able to ensure it is properly recycled.

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    dsc_0062

    We’ll be returning to speak to Janet about how the build is going, but you can also follow its progress in The Hub with regular video updates.

     

    Other examples of the PH15 timber frame system

    The orange colour are LVL’s (laminated veneered lumber) which are structurally quite strong, so are used for larger beams. The orange is a coating they put on to give a bit more moisture protection to avoid swelling on site should the contractor allow them to get saturated! The blue is a special insulated triangular lintel which is made up (and delivered ready made to site) to allow the windows to sit right up against the eaves without creating a terrible thermal bridge.

    Akerman Project
    Akerman Project – three terrace houses

    Tring project
    Tring project – detached three bed house

     

    Find out more

    Visit the website of Passivhaus Homes

    Visit the website of CTT Sustainable Architecture

    Follow Passivhaus Homes on Twitter

     

    Transcript

    Download a transcript of the interview with Janet Cotterell.

     

    The Hub update

    If you’re a Hub member you can watch the videos of the build as progress continues.

    If you’re not yet a Hub member and would like to find out more information, you can watch our short video which explains what it’s all about.

     

    Passivhaus Explained

    Here at Regen Media we recently produced a video for Architype, who wanted to create a training / induction aid to help newcomers understand what Passivhaus at Wilkinson School is all about. A big thank you to the four young stars of the piece who we think you’ll agree explain Passivhaus brilliantly!

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