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Tag: Passivhaus Institute

  • HPH293 : What is Passive House Accelerator? – with Zack Semke

    HPH293 : What is Passive House Accelerator? – with Zack Semke

    Zack Semke explains why he’s passionate about facilitating the communication and flow of information around Passive House.

    Interview with Zack Semke

    Zack is based in Seattle, where he works in marketing consulting services for the high-performance building industry. He is also a director of Passive House Accelerator: a website that brings together different sources of information to educate, inform, and promote the work that is being done by the Passive House community.

    The construction industry has lacked innovation

    Compared to other industries, construction has been famously lacking in innovation, but Zack says that Passive House is changing that. By using physics to understand how to design and construct buildings better, Passive House is re-thinking the basics of the skeleton and skin to improve performance.

    The learning from new technologies will drive down costs

    Zack uses the example of solar energy to show how there has been a massive drop in the cost in recent years.

    He attributes this to Wright’s Law and the learning curve effect, which applies to all technologies. It says that for every doubling of units produced, there will be incremental reductions in the costs. This is brought about by the additional learning and micro-innovations that happen across the supply chain. In the case of solar energy, Zack says it looks as though every doubling of solar panels across the world brings about a fall in prices of 30%.

    The same principles can be applied to Passive House buildings, so that costs can be driven down to more of a cost parity with conventional construction.

    There has also been progress in the components supply chain over recent years, with triple glazed windows for example coming down in price.

    And once costs become on a par, it becomes a no-brainer to build Passive House, with all the lower energy and health benefits too.

    “That’s why I’m so passionate about facilitating communication and flow of information between practitioners, policymakers, marketers and whoever it is, because we want to accelerate this process as much as we can so that when a project happens in the UK and there are lessons learned from that project, we can see that learning being applied in Seattle for example.”

    We know what we’re getting with Passive House!

    Zack credits the focus on physics as providing such an important contribution to the sustainability movement. The development of tools like PHPP, which are not too complex or too simplistic to use, mean that there won’t be the performance gap that can be found with other green building standards.

    There will be a wave of uptake

    Zack is encouraged by the explosion of Passive House that is happening across parts of North America, particularly in Vancouver where enlightened public policy is incentivising Passive House and net zero construction, and New York City where carbon emission restrictions on existing buildings are being imposed, paving the way for huge numbers of deep energy retrofits.

    And whereas the Living Building Challenge has been incentivised, it was designed to be exactly what it says – a challenge. Zack says that it doesn’t factor in scalability and is seen as the moon-shot of green building. Passive House on the other hand is set up to be cost optimised.

    “As cities become actually serious about delivering on climate goals, they’ll recognise that there is no other green building standard or approach that rivals Passive House on reducing operational carbon emissions.”

    He gives the example of affordable multi-family buildings in Pennsylvania. The body that oversees the funding, the Pennsylvania Housing Finance Agency, has prioritised Passive House in their scoring for projects that are looking for funding. It doesn’t cost the state anything to add that as a priority, and the result is that developers know if they include Passive House in their schemes they will be at greater chance of securing funding against competitors. This has seen a wave of Passive House construction of affordable housing in the state.

    Pax Futura Passive House apartment building in Seattle. An example of the kind of urban infill, multi-family Passive House building that we will need to see more of in order to address the climate crisis.
    Image Copyright Cascade Built

    Embodied carbon is a challenge we have to address

    “Operational carbon is the first thing that we need to tackle in my view, but just like so many things in the climate action space, it’s not an either/or conversation.”

    Zack credits the Living Building Challenge for the new zero carbon certification, which is one of the first to consider how to reduce and offset embodied carbon.

    He says the Passive House community is embracing embodied carbon as a challenge, and the Passivhaus Institute is dedicating resources to its research and thinking about tools for how it could be addressed. He would be keen to see them including energy-related embodied carbon calculations and looking at the implications of those decisions.

    The Passive House Accelerator shares information and innovation

    Created just over a year ago, the Passive House Accelerator is an open source global platform, that is partly a place that shares content that others have created about Passive House. They also host virtual weekly presentations by Passive House experts, followed by Q&A sessions on screen.

    In addition, they present a podcast, and host roundtable discussions, on a variety of related topics.

    Find out more

    Visit the website of Passive House Accelerator

    Follow Zack on Twitter

    Transcript

    Download a transcript of the interview with Zack Semke.

    Climate Champions Podcast

    Hattie Hartman, Sustainability Editor at the Architects’ Journal, has launched a new podcast with architect George Morgan from One Point Five Architecture.

    It aims to share knowledge in an era of climate emergency, speaking to change-makers and innovators who are transforming architecture as we know it by designing in ways that respect planetary boundaries

    Find out more.

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  • HPH263 :A step-by-step EnerPHit retrofit of a mid-terrace home – with Harry Paticas from Arboreal Architecture

    HPH263 :A step-by-step EnerPHit retrofit of a mid-terrace home – with Harry Paticas from Arboreal Architecture

    Harry Paticas of Arboreal Architecture explains why care and hard work have been so important to the retrofit of his 1978 mid-terrace townhouse.

    © Agnese Sanvito

    Interview with Harry Paticas

    Harry has a background in art and maths, which he then followed with a degree in architecture. He says the turning point in his twelve years in practice as Arboreal Architecture was taking the Passivhaus training course and suddenly being able to understand how buildings perform.

    Together with his interest in building performance and the natural world, he also has a passion for retrofit, and is currently getting towards the halfway point of a phased retrofit of his own house, a project which was overall winner at the inaugural ASBP Awards 2019.

    “When you put passion in, you get something out”

    The house was purchased in 2016 with the aim of doing a retrofit project. Although they had intended on finding something a bit cheaper so they would have more money to spend on the works, this house cost rather more than they had budgeted for which is the reason they are not currently as far along as they had hoped.

    It is a south facing, slightly staggered mid-terrace property. It is a combination of a solid brick and block front wall that is tile clad, while the back wall is brick both sides with a cavity.

    © Agnese Sanvito

    It has been an intensive couple of years working on the house, with every Sunday taken up by long hours of DIY. It has been a massive learning journey which Harry says has also been of benefit professionally.

    Not only has the DIY element of the project been hugely rewarding, but it works in parallel with his professional role where he can now speak even more confidently and knowledgeably to clients. This could be about how the MVHR functions, how often you need to change the filters, how the pipes connect etc. Likewise, it aids with speaking to builders and helping them do a better job, which gains more respect from them in turn.

    The strategy involves four phases

    The first phase involved work being carried out before they moved in. They had sold a property and were renting so that they could get any of the dangerous, dusty and cold work out of the way while living in their rental accommodation. This included asbestos removal from ceilings, airtightness works to the ceiling on the top floor, putting in and taping vapour block boards to each other and to the walls, adding insulation to the loft, making the house secure and weathertight and installing three triple glazed windows.

    Generally the plan has been to work from the top of the house down to the bottom. Following the loft works and triple glazing to the front elevation they added insulation to the walls of those rooms. By this time they were living in the house and noticeably felt the thermal shift during the winter weekend when they added the cork insulation to the walls.

    A key part of the strategy was maintaining good quality ventilation before the MVHR unit was even installed. With the existing leaky double glazing they knew it wouldn’t be a problem, but when they were replaced with the triple glazing they specified night vents. These allow the handle to be put to 45 degrees off the vertical which gives a 3mm opening in the window at the top. This meant they could maintain decent air quality as an interim measure without the need for installing trickle vents.

    By doing lots of monitoring of particulate matter, nitrous oxide, carbon dioxide, temperature and moisture content, they could use the information to decide whether night vents should be open or not.

    Harry is currently finishing off bits of airtightness work and interior decorating of phase two before working on the next big phase which will be working out where the living space is going to be. The plans they submitted to the Passivhaus Institute had it on the first floor, but they’re now thinking of having it on the ground floor.

    © Agnese Sanvito

    According to their EnerPHit retrofit plan, the next phase is to temporarily insulate the garage door. This will instantly reduce heat loss through the whole of the living room floor, the ground floor hallway and a back wall of the garage. In order to do that they will need to block the door and create a new entrance into the garage.

    Along with insulating the porch and insulation to the bathroom, these will form phase three, with phase four being the ground floor front and back insulation, and insulation to the floor.

    Cork has been used for internal insulation

    Harry was always going to use an insulation material that was from renewable sources. He also wanted something that wouldn’t off-gas but be neutral in terms of air quality.

    His work with Jane Anderson on embodied and sequestered energy in a range of insulation materials has shown that cork actually has lower embodied energy than wood fibre, and is very good on both counts.

    It hasn’t performed as well as hoped in the heat

    While internal temperatures have reached 27 degrees, it hasn’t overheated in the Passivhaus terms of over 20 degrees for 10% of the year. With the new windows they are getting 20% less sun through, but with the cork they’re not getting much effect from decrement delay. They have a medium thermal mass and the top floor doesn’t cool down very quickly because of the blockwork walls and brick party walls.

    Currently being made are three bright yellow sails which can be attached to the front of the house and shade 100% of the top two windows and over 50% of the large living room window. They will provide a low carbon, low tech solution to shading and reducing overheating, and which can be packed away in a bag in the loft when not needed for the rest of the year. They will also be able to judge their effectiveness scientifically as they have installed sensors on the inside and outside of various rooms of both theirs, and their neighbour’s house for comparison.

    It’s also about respecting materials that are already in the building

    The process they have adopted has been to try not to replace something if it actually works quite well.

    “So there’s a little bit more of a lean towards embodied carbon, rather than very demanding interior design aesthetics.”

    This has led to what Harry calls some ‘fun moments’ and to a little bit of variation, which they’re accepting of and saying that’s what this is about, rather than trying to put his architectural stamp on everything and making it as perfect as possible.

    It has been an education for his son

    With Harry’s son soon turning eight, he was keen for him to be involved and remember the experience as much as possible, with a deep understanding of what it is they were doing and why.

    With only a little encouragement at first, his son has been producing a series of A3 posters with images, annotations and diagrams, about cork, airtightness, a thermographic survey, insulation and mechanical ventilation with heat recovery.

    © Agnese Sanvito

    His teacher engaged with the process and has encouraged him to display them in school and do presentations about them to his class.

    A direct result of the school presentations is that Harry is starting a charity or community interest company which will be about retrofitting schools. He will be delivering thermal performance workshops to school children and doing research with them where they look at the fabric of their classrooms and the school and coming up with a retrofit masterplan.

    There have been particularly pleasing elements

    Having never had them before, Harry particularly loves the triple glazed windows, which is an opinion shared by visitors to the house. They are inward opening with a central flying mullion which allows them to open up a whole elevation and achieve very rapid night time cooling.

    © Agnese Sanvito

    Another favourite feature is the MVHR unit. They still open windows when they want, but for general air quality which has been backed up with numerical evidence from their monitoring, it has been particularly pleasing.

    © Agnese Sanvito

    Harry says that working with and getting to know materials has also been lots of fun, particularly with the cork.

    Find out more

    Visit the website of Arboreal Architecture

    Follow Harry Paticas on Twitter

    Support Harry’s petition for zero rate VAT on deep retrofit

    Transcript

    Download a transcript of the interview with Harry Paticas

    Please connect with me

    Subscribe, rate and review the podcast in iTunes

    Rate and review the podcast on Stitcher

    Like our Facebook page

    Follow us on Twitter

  • HPH103 : Is Building a Passivhaus Expensive? – with Geoff and Kate Tunstall

    HPH103 : Is Building a Passivhaus Expensive? – with Geoff and Kate Tunstall

    Geoff and Kate Tunstall explain how they were able to create a fantastic Passivhaus in Denby Dale with a budget of around £150,000.

     

    Interview with Geoff and Kate Tunstall

    When Geoff and Kate decided to self-build and downsize for their retirement, their first idea was to build a dormer bungalow with a conservatory. Following a conversation with Green Building Store, they were encouraged to explore Passivhaus as an option.

    Geoff_Kate

     

    Back in 2008 there weren’t any examples of Passivhaus in the UK that they could visit, so they travelled to Austria. After visiting two properties there which had temperatures of 20/21 degrees, despite outside temperatures of -4 degrees, they made the decision that if they could afford it, this was how they wanted to build.

     

    Paying a Ransom Strip Demand Used Up Their Contingency Budget

    The plot for their build was at the bottom of the garden of their existing house. Unfortunately a builder had bought the plot of land behind this and, based on the value of the plot, demanded £30,000 for a six inch ransom strip that they needed to provide them with access from their building to the road behind. After a year of fighting this, and the builder realising that the money was their contingency so it was this or nothing, they eventually agreed to pay a total of £18,000, which used up their contingency before the build had even started.

    During that year however, the designs for the house were all researched and finalised to the extent that as soon as the ransom strip issue had been resolved they were able to progress straight away with the build.

     

    Making a 3D Model Helped Their Understanding of the Scale and Spaces

    Originally they wanted to build a bungalow but the plot size didn’t make this feasible. Kate found it useful to create a 3D model out of balsa wood to get a better idea of how well furnishings would fit and how comfortable the spaces were likely to feel. They also found using the model was a helpful way of explaining their ideas to the building team throughout the process.

    Kate's-model-of-Denby-Dale-Passivhaus

     

    An Important Feature was to Have Light and Warmth Throughout the Fabric of the House

    Particularly because their last property was a dark and draughty cottage, Geoff and Kate were keen to build a warm and contemporary home with lots of natural light. They had to abandon their original conservatory idea after running it through PHPP, but instead they remodelled it to feature a two-storey solar space which beams the light throughout the house.

    Denby Dale 2

    Denby Dale 1

     

    Using Kate’s 3D model they realised that one of the bedroom windows seemed uncomfortably small. Again using PHPP the design could be changed to accommodate a larger window by adding higher performance floor insulation to compensate.

     

    Keeping Within Budget was a Collaborative Process

    From the outset, everyone knew the budget was only around £140,000. With regular meetings between themselves and the design team throughout the design process and the build, they were able to keep on top of what was happening, when, and how much things were going to cost.

    Living on site was a help because they were able to spot any little details that needed changing before the build progressed too far and became too expensive to amend.

    Geoff explains that on a Passivhaus there are certain non-negotiable things that need to be budgeted for and for which there are no short cuts, such as triple glazing and the ducting for the MVHR. Where they saved money was by spending time researching things like inexpensive lighting and kitchen units.

    Denby Dale 3

    Denby Dale 4

     

    “But it was a good discipline for the Green Building Store and ourselves to actually work to a figure, a limited figure, because it proves that Passivhauses can be built to a reasonable budget. And the budget for our house isn’t a lot for what we’ve got.”

     

    The Build Wasn’t Without its Challenges!

    One of the biggest challenges they faced was building throughout one of the coldest winters in a generation. It was too cold to use the paint they had planned, mould spores started showing on the clay plaster and they had to put up a screen so they could continue working in the howling gales and snow.

    A further challenge was the corner windows of the solar space, both from a Passivhaus point of view but also a structural one. They needed to make sure there wouldn’t be too much solar gain, and also ensure that the structural support would be inside the thermal envelope.

    Denby Dale 5

     

    The House Exceeds Expectations

    Geoff and Kate have been living in their house for around five years. They wanted a house that could be kept clean easily, that would provide warmth when needed, that would be energy efficient and not amass big fuel bills during their retirement. It has achieved all of these and something which Kate hadn’t focussed on before they started was how important it is to have a healthy house. She describes it as being a calm, tranquil and healthy place which will benefit them in their old age!

    One of the Passivhaus buildings they visited in Austria had some underfloor heating so Geoff and Kate assumed they should put it in their kitchen and bathroom. In hindsight they didn’t need to as it’s actually never been used.

    Geoff is adamant that anyone embarking on a self-build project should go and visit a Passivhaus. Once they’ve experienced it he’s quite sure that’s how they will then go on to build. He says that even if the initial outlay is a little more expensive, it will pay for itself within three or four years, and be future proofed against rising fuel prices.

    Denby Dale 6

     

     

    Find Out More

    Find out more about Denby Dale in the Green Building Store blog.

     

    Transcript

    Download a transcript of the interview with Geoff and Kate Tunstall.

     

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  • HPH097 :What Do You Get for Passivhaus Certification? – with Peter Warm from WARM

    HPH097 :What Do You Get for Passivhaus Certification? – with Peter Warm from WARM

    Peter Warm from WARM: Low Energy Building Practice explains why building to Passivhaus standard is desirable, how certification comes into the equation, and what steps will increase your chances of reaching certification.

    Peter-Warm

    Interview with Peter Warm

    Peter has been an energy engineer all his working life and is fascinated by high performance buildings. Through his involvement with the AECB he got into Passivhaus certification, and this is now a key service offered at WARM: Low Energy Building Practice.

    floor to ceiling glass

    “Glass Boxes are a Huge Problem”

    One of the biggest challenges WARM face is communicating to architects that vast quantities of glazing in a Passivhaus actually create a “solar cooker”. While the glazing is expensive it also creates a problem which will need remedying with the additional cost of solar shading.

    “Glass boxes” are effectively huge energy consumers, either for heating or cooling.

    Passivhaus Certification is a Form of Training for Designers

    Peter thinks of the certification process as a form of training because it gives designers a deeper understanding of how the decisions they make impact on the energy performance of their buildings.

    If the designer hasn’t reached the Passivhaus standard before then inevitably there is a learning curve. However, the certification process provides support throughout, in order to iron out any issues before they occur.

    For designers that WARM have worked with many times before they will be offered a greatly reduced quote because they need far less hand-holding throughout the process. In these cases, it’s really all about the documentation.

    “Passivhaus Certification…It’s Just About Building Buildings Sensibly, Doing it Properly”

    Peter suspects that in 20 years time the current quality of a Passivhaus will be the norm for a new build. Although much of the UK construction market is currently lagging far behind in terms of build quality and low energy standards, Peter sees retrofits as being a greater challenge for the future. There needs to be more education about the dangers of getting insulation wrong which – if not done properly – can cause mould, condensation and rot as well which in turn can impact on the occupants’ health.

    passivhaus-certified-building-250

    The Steps to Certification

    The Quote – This is based on the plans and sketches, an idea of how long the process is going to take and the level of support the designer is likely to need.

    Design Review – It is important to review the designs before planning to look at the impact of things like the form factor (on insulation and airtightness) and fenestration (on solar gains).

    Checks Before Going On-Site – WARM will usually do their own PHPP calculations to check thermal bridging, airtightness, heating, ventilation, etc.

    On-Site Checks – This doesn’t usually apply to small projects. On large ones there can be a high turnover of tradespeople so the checks are helpful in identifying any problems at the time.

    The Air Test – Along with the air test they check the commissioning report for the MVHR and make sure the system is working properly and quietly. If they’re happy with everything the information is sent to Germany for the authorisation to issue the certificate.

    WARM Certification

    Reasons Why Buildings Fail Certification

    Airtightness – Failing to test while there is still access to the airtightness layer can be a big issue in one-off houses. This needs the doors and windows to be put in at an earlier stage than a builder would normally like.

    Building Services – This usually applies more in larger buildings. In particular it is poorly designed or installed ventilation units. When this happens the fan has to work harder which means greater noise.

    Not Consulting Throughout – Less common is when people just build their buildings and then approach WARM for certification once it’s complete. In this instance it is likely they will not reach the standard.

    As Passivhaus is about the comfort of the occupants, failing certification will mean that it may not be as comfortable as they would like, perhaps living with draughts and MVHR noise. Peter says: “Comfort is one of those strange things where, if you notice it, it’s not comfortable.”

    Airtightness was the Biggest Challenge for WARM’s Own Office Retrofit

    Built in the 1960s, they have transformed a draughty first floor flat into an EnerPHit standard office.

    They achieved this by insulating externally, filling the cavity, insulating between the office and the shop, and putting in roof insulation at rafter level.

    Deciding where the airtightness layer was going to go was the biggest challenge, particularly as the shop below was not part of the retrofit.

    All the windows were also replaced with high performance triple-glazed windows and an MVHR system was installed.

    Admirals-Hard-wall insulation
    Admirals-Hard-roof-structure

    Inevitably Building Regulations will Catch Up with the Passivhaus Standard

    Peter considers Passivhaus as being such common sense that he believes it is inevitable that regulations will eventually meet the standard. With building regulations changing every few years to require more insulation for example, by choosing Passivhaus now your project won’t date.

    Peter says: “It will happen. You’re just making it happen a little earlier.”

    Find Out More

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    Transcript

    Download a transcript of the interview with Peter Warm.

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