Contact →

Tag: Enhabit

  • HPH288 : Renovating a 1960s house for comfort and efficiency – with Russel Hayden

    HPH288 : Renovating a 1960s house for comfort and efficiency – with Russel Hayden

    Architect Russel Hayden explains how he sought to renovate a derelict 1960s house to EnerPHit standards.

    Interview with Russel Hayden

    Russel is an architect who, up until four years ago, had spent his whole working life in London. Prompted by a desire to leave London and move closer to family, he and his wife bought a derelict house in Stockport with the intention of it being a project to renovate, before selling it on and moving out of suburbia.

    They bought the house through a sealed bid system

    At the time, Russel and his family were renting out their house in London and lodging with his in-laws in Stockport when the house opposite came on the market. It had been left in a state of abandonment for around ten years after the owner had died and heirs were being sought.

    The house went to sealed bids, and they won it with a bid of 5-10% over the asking price.

    The budget was set by what they thought the house would be worth when complete

    At around the same time they left London, they received an inheritance which enabled them to buy the house in Stockport, with enough left to cover the renovation works. Despite a few little extravagances, they mostly kept things simple, and having the budget set gave them a clear direction and target. They did end up spending a little more than they expected to, but felt they got good value.

    Upon completion, they had the house valued at significantly more than they had expected. And despite thinking this project would be a stepping stone to something else, they love the house and the area, and have no intentions of moving.

    Time pressures meant there was no fixed price with the builder

    As they hadn’t finished all the drawings, they recruited a local builder to get the house stripped back while they were still living in London. Once they moved, Russel was able to take on the project management role, finish the drawings and oversee the procurement of materials.

    Having that experience and understanding now, he does acknowledge a new found respect for builders for the work they put into getting the materials, finding the right price and coordinating their delivery.

    The builder embraced the learning involved

    The builder had been recommended to them, and although he had never done a project like this before, he had a good attitude and a genuine interest in learning about Passivhaus. That’s not to say there weren’t also times where he found it frustrating not being able to carry on with his work in the usual way.

    Russel paid him and his team of two helpers a daily rate, which isn’t something he would necessarily recommend a self-builder do, but he was living opposite with his in-laws and could be on-site every day to keep a close eye on things.

    Passivhaus consultants were employed

    Russel had done the Certified Passivhaus Designer course before leaving London, so understood the principles involved, but knew that he didn’t have the experience to tackle it on his own.

    They engaged Enhabit to help with the Passivhaus consultancy, who set out four options of how far they could take it: getting it to Building Regulations standard, to AECB Silver, to EnerPHit, and to Passivhaus standard.

    With Russel effectively wanting to use it as his business card for his new venture in the north, they felt it was important to do something that was certifiable and within a reasonable cost. Settling on EnerPHit basically then set their brief.

    “On reflection, it was a very helpful device actually because it then made everything very clear about what we had to do. I think that’s one of the beauties of Passivhaus. Although there are infinite ways of achieving it, you do have a very real target.”

    The building was wrapped externally with insulation

    The house needed a new roof, so making the decision to go with that and wrapping the brickwork in external wall insulation, gave them a clear steer of how they were going to develop the project.

    They sought planning permission because the 280mm insulation would increase the house footprint by around half a meter, and with an extra foot of height on the roof ridge line.

    One of the biggest challenges was with the concrete slab floor, and the problem of the cold bridge at the perimeter. Without wanting to spend huge amounts of money on it, they decided to accept there would be a cold bridge there, but put insulation on the retained slab. They mitigated that by dropping 150mm of insulation externally down to the foundation level.

    They kept structural changes to a minimum

    By deciding not to move windows and doors around unless absolutely necessary they were able to keep the costs down. They did need to remove a chimney breast though, as it wouldn’t have worked with Passivhaus.

    Adding the floor insulation meant the floor was raised to the level of the first step on their stairs. On the first floor they removed the ceiling plasterboard to expose the joists and give a sense of a bit more height.

    Copyright The Modern House

    One of the big changes they made was reducing the size of the garage and extending onto the back of it to make a space that is used as a garden room, office, and exercise studio. It has a timber frame construction with a straightforward flat roof, making it a cost-effective addition to the project.

    Russel’s wife Anna is also an architect and she spent a lot of time researching materials for the interior finishes, and finding fittings which weren’t necessarily particularly expensive.

    They chose a parquet flooring for the ground floor and a lighter oak parquet for the upstairs, which together with the full height doors in the rebuilt partitions, gives continuity between the spaces.

    They fell just short of their airtightness target

    One of the biggest challenges on the project was getting the connection to the existing house right, and particularly minimising the thermal bridges where the garage and extension connect.

    Russel thinks the workmanship around that connection was responsible for them just failing to achieve their airtightness target, with a result of just over 1.1 (where 1.0 is required for EnerPHit). By the time they had that final airtest they were past the point of being able to go back and remedy where the problem may have been. This did mean that frustratingly they weren’t able to get the certification they were hoping for.

    The hands-on experience has been invaluable professionally

    Among the things Russel learnt from this project, was about having the right and patient approach with people. This was particularly the case with having employed a builder on a daily rate rather than a contract.

    He also found that being so involved on site and doing the taping himself, meant that he was gaining a much better understanding of things that worked and things that didn’t, which invariably will influence the way he goes back and details buildings.

    “I think what’s been brilliant about the Passivhaus Designer Course is that I’ve realised that for the last thirty-odd years I’ve been detailing and designing buildings not terribly well without a proper understanding of moisture and how buildings work, thermal bridges and things like that.”

    Copyright The Modern House
    Copyright The Modern House

    He is now working on a Passivhaus self build

    They have since bought a 1960s concrete panel bungalow in the Lake District which was won through another sealed bidding process. With the bungalow quality not living up to that of the view, it became quickly apparent that their best option would be to demolish and replace it with a new building. It is currently at the planning stage and they are looking to make it a timber frame construction built to Passivhaus, or ideally Passivhaus Plus, standards. Being in a World Heritage Site they are keeping their fingers crossed!

    Know your limitations and keep things simple

    For anyone thinking of carrying out their own retrofit, Russel says the budget will be key but it can be very difficult to know how far you can go within that. The balance between getting to the level of comfort required without spending a huge amount of money can be a challenge.

    It is easier if a particular standard is the target, but without that you are left with a number of options.

    It is best therefore to understand the difference between what you want to spend and what you need to spend. Spend it carefully and you’ll get what you pay for. By keeping it simple it will be easier to design and build, and you’ll get a lot more for your money.

    Find out more

    Visit the website of HESKETHHAYDEN

    Follow Russel on Twitter

    Transcript

    Download a transcript of the interview with Russel Hayden.

    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

  • HPH245 : How do you create a healthy home? – with Elinor Olisa

    HPH245 : How do you create a healthy home? – with Elinor Olisa

    Elinor Olisa explains why her family’s health was always paramount to the decision making on this build.

    Interview with Elinor Olisa

    When Elinor and Born made the decision to self build, they realised they could create an environment that was a safe haven for their children, where they were free to live without restrictions as far as possible.

    “This house very clearly for us was going to be about the health and the future proofing. And in doing that, we can make choices that will be good for the environment, good for our bodies, good for our well-being when we’re in them.”

    Health considerations were fundamental

    Both boys have severe, life-threatening, anaphylactic allergies to a number of things, including wheat, dairy, eggs, nuts, soya, pulses and oats. The severity of their reactions can vary according to their health and immune systems at the time, so it was very important to Elinor and Born that they create as healthy environment to live in as possible.

    Researching building materials’ impact on health was challenging

    Elinor and Born are used to researching online for clothes and products for the boys, and reading the fine detail to make sure they’re suitable. Both boys are allergic to wool and they have had to be careful to find breathable materials that wouldn’t irritate their skin.

    “So, we said we’re just going to do our very best to research every single product that comes into this build and do it in the same way that we would for any other item that we were sourcing for the children.”

    But when it came to researching building materials and interiors, they discovered it was much harder to find the information about how they would impact on health, particularly from UK companies.

    As a consumer, ask questions

    With the growing popularity and interest in gluten-free and vegan eating, and also tragedies we hear about of the impact that improper labelling can have on people with allergies, Elinor believes that it is now more acceptable than ever to be asking those questions about what is in the food, without being judged as picky eaters.

    When it comes to the construction industry, she believes that companies need to start being more transparent about their products and shouldn’t be able to sell items that have poisonous paints, glues and MDF.

    “The largest piece of learning that I took away from doing this build was to ask questions. It’s not to just assume anything. Don’t assume that because somebody is selling it, that this is something that is okay for you to take home and have. Do your research, take responsibility for it, and ask questions. Because I think by us as consumers asking questions of retailers, they will become more willing to label things better and to give you more honest answers about the make-up of their products.”

    Environmental sustainability was an important factor

    They were also very conscious on their build to be as environmentally sustainable as possible.

    “(We) hope(d) that we could make less of an impact, feeling thoroughly horrified by the amount of rubbish that our build did produce. We did start to look to second-hand products, and we did look for upcycled things and we did look at what we’d already got and thought, rather than throwing it away, what could we do to it that would make it fit this space.”

    Plants were chosen carefully

    The choice of plants in their home was given careful consideration. They would always check whether it would have a neutral, harmful or positive impact on the house, and there was plenty of useful information available online to help.

    They have used lots of plants indoors that improve the air quality, and usually avoid fresh flowers because of the pollen. In the garden they have plants that are bee-pollinated, which is more localised, rather than tree-pollinated, which can be more of an air-born irritant.

    “That said, having the garden, having the outside, our children go outside, they go to the park, they go to the playground at school, they go to the woods, they do all of those outside things. So, they’re going to come in contact with it. We live near a very busy road. There are all sorts of things we cannot possibly control. It’s just what we’re doing within our little, small environment here.”

    Passivhaus was an easy decision

    One option their paediatrician suggested was a clean air chamber for the children to sleep in, which in studies had shown high success rates at improving immune systems and asthma and allergy symptoms. Elinor and Born weren’t keen on the idea of a chamber for the boys to sleep in, but on hearing about MVHR units, they realised the concept could apply to the whole house.

    The plot was only available to families

    With a lack of success at finding a property to purchase, they made a successful bid for a plot of land in London. It came with a caveat that the people who were selling it, wanted a family to live on it. Elinor suspects without that caveat they would have been unable to compete against developers for it.

    Amendments were made to the previously approved design

    The plot was a back garden piece of land which already had planning approval. The approved house was cleverly designed to comply with the restrictions around height and size. They felt it was a beautiful design which took into account that they would need to dig down to create a family-sized home. They worked with their design team to adapt the original plans to suit their budget and lifestyle.

    Access restrictions determined build system

    A temporary right of way across another plot was the only way construction vehicles could access their site. And with that other plot also being up for sale they were unsure as to who would buy it or whether they would continue to be allowed access. The necessity therefore was to build the house as quickly as possible.

    Below ground they used concrete and above ground they used pre-fabricated, Passivhaus approved SIPs panels to help the build go up quickly.

    In hindsight Elinor thinks what they should have done was said they needed a specified amount of time to complete the build once they’d broken ground, rather than committing to their access running out on a date in the July. Fortunately they were granted longer access but it was an additional stress on the building process.

    Gaps in communication

    Elinor used Enhabit for the design and build of the structure, while doing the rest of the procurement themselves. While having that level of involvement did save themselves some money and give them control over the decisions, Elinor does see the benefits that having a company oversee the whole process would provide.

    Although their team all worked well together they did occasionally come across issues that seemed to fall outside of the remits of everyone involved.

    Lighting can impact on health

    Although lighting was not something they had given much thought about in previous homes, they employed a lighting designer on their project who was doing research into the benefits of light on health.

    Lighting was a concern for the basement area, with worries about whether they would have the feeling of daylight, but they have used biodynamic lighting which is a gentle and adaptable system. Across the building they have some feature lighting, and also general lighting.

    They are now aware of how much impact lighting can have on comfort within a space and how it can play an important part on health.

    Everyone feels healthier

    The family are loving being in their new home and are reveling in a sense of relief and achievement.

    While the impact on the boys’ allergies won’t fully be known until they re-take an allergy test, Elinor has noticed they are having far fewer reactions to things and the asthma attacks have reduced. As a family they are sleeping better and feeling healthier and happier.

    “If we were to give advice to anybody, it would be I think we can all make changes in our existing homes. You don’t have to build a house to do this. There are changes you can make in your existing home that can have a significant impact on your overall health.”

    Find out more

    Visit Elinor’s Healthy Heroes website

    Follow Elinor on Instagram

    Transcript

    Download a transcript of the interview with Elinor Olisa.

    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

  • HPH172 : The impact of setting your energy target – with John Palmer from Enhabit

    HPH172 : The impact of setting your energy target – with John Palmer from Enhabit

    John Palmer from Enhabit explains what happens if you choose not to go all the way to Passivhaus standard, including how this impacts on cost, energy efficiency and comfort. He also outlines a best practice approach if you are going to build with Passivhaus principles.

    Interview with John Palmer

    John is the Managing Director of Enhabit, a company that helps to improve building performance, efficiency and comfort levels. John is a qualified Passivhaus consultant, SAP and BRE Assessor, systems engineer and experienced project manager. Prior to joining Enhabit, he ran his own low energy design consultancy.

    First understand the implications of Passivhaus for your project

    If you are trying to set an energy target, John’s advice is to start by reviewing your plans in line with Passivhaus standards. This will allow you to fully appreciate what it might take to achieve Passivhaus. Once the implications are understood, you may take the necessary steps or make a conscious decision to compromise and aim slightly lower.

    Invest in professional advice at the design stage

    John says that Passivhaus is not so much more complicated than a normal build, it just requires more thought at the beginning. One of the key thermal bridges to eliminate or mitigate is where the ground floor meets external walls, which will require careful detailing and potentially some specialist materials. Paying for some extra time with your architect or Passivhaus consultant is a worthwhile investment.

    When clients commission a design review with Enhabit, they are shown a Passivhaus model of their design and given graduated options to see what’s possible with their house and how close they can get to Passivhaus, with indicative costs for extra requirements.

    Focus on a fabric first approach, not eco technology

    John says it’s easy to get bamboozled by all the technology available. Ground source heat pumps, solar panels, boilers, etc. all have a design life of around 20-25 years and will need to be replaced. However the walls of your building will be there for 80-100 years, so the extra investment you put into them at the start will repay itself time and time again.

    Architectural aspirations may make Passivhaus harder to achieve

    John explains that in Passivhaus terms, the shape of your house is the ratio of your liveable area to outside heat loss area. So you may need to compromise on an ambitious design if you want to target Passivhaus.

    If your plans have already incorporated professional advice, and you intend to follow a very high-performing fabric first approach, it may be you just need to add in a MVHR (mechanical ventilation with heat recovery) system.

    Alternatively you may find you haven’t gone far enough with the fabric of the building and need to change the specification of insulation, glazing, etc. This is typical of retrofits, where John says it’s quite hard to achieve the levels required for Passivhaus with the existing fabric.

    Heating a Passivhaus costs a very small amount

    The annual space heating demand in a Passivhaus should be no more than 15 kilowatt hours per metre squared per year. John comments that this is a very specific number and you may decide this is unachievable.

    The key is to understand what number you can get down to, and what that means. For example, a target of 30 kWh will cost you twice as much to heat your property in any given year than it would have done if it were a Passivhaus. But heating a Passivhaus costs very little, so doubling very little isn’t that much and is likely to be better than other new build properties in the UK.

    Every design decision will impact on comfort levels

    Doubling your space heating demand to 30 kWh will impact on comfort but the nature of this impact will depend on why you haven’t achieved the Passivhaus target of 15 kWh. John gives a few examples:

    IssueImplicationsImpact On Comfort
    Insufficient insulation in wallsHeat loss from wallsFeeling cold off the walls
    Poor detailing where walls meet ground floorThermal bridgingIf bad, noticeable cold spots and possible condensation/mould
    Window specification isn’t triple/ high-quality double glazingCold will radiate off the glazingFeeling cold in rooms at certain times of year

    Thermal comfort is all about constant temperatures

    Many homes, especially Victorian buildings, tend to have rooms that are hot near the ceilings but cold at lower levels due to drafts and a lack of insulation below the ground floor. John explains that although the average air temperature in the room might be ok, having cold feet and a hot head will feel uncomfortable! Paying attention to thermal bridges and insulation will help to achieve what John calls good temperature stratification.

    Building regulations rely on people opening windows for required ventilation

    Although our awareness of temperature is quite good, it’s harder to detect poor air quality. We may notice smells and detect when rooms are a bit stuffy, but that’s about it.

    Humidity, VOCs (volatile organic compounds), odours and nitrogen oxide levels are all examples of pollutants within buildings. John advises we need about 30 cubic metres of fresh air per person per hour moving through a property to deal with pollutants, but this isn’t achievable with trickle vents and extractor fans unless you start opening windows.

    An MVHR system will deliver the required level of ventilation, but there are other mechanisms out there superior to extractor fans that will give extra ventilation but perhaps not cost as much.

    Insulation, glazing and ventilation will cost more, but not much more

    These three aspects are typically more expensive than a normal new build, as a Passivhaus requires:

    • More insulation – but you’ll only be paying more for materials (approx. 0.5% increase on overall cost); the labour costs are the same
    • Triple glazing, for thermal performance and to avoid condensation and mould – the gap is closing between triple and double glazing prices
    • An MVHR system – for an average sized house this may cost £9-10k for supply and installation

    Of these, the greatest return on investment will be insulation.

    Some builders are willing to learn

    Hiring the right people to build a Passivhaus is another factor to consider. Although it’s still relatively new to the UK, John has found that builders relish the challenge of doing something that requires more detail and thought; they appreciate the ability to measure how well they’ve done, and revel in achieving the standard. He adds, “You have big, hairy builders hugging each other on site when they get their final air test and they’ve got down to the right levels.”

    Five helpful tips from John

    1) Visit a Passivhaus or speak to someone who lives in one, to see what it can deliver from a living experience

    2) Find out what would be involved in achieving Passivhaus for your project

    3) Understand how each decision affects the final design, floor space, efficiency and comfort

    4) Put an MVHR system in, regardless of your airtightness target; ventilation and air quality are worth doing as standalone

    5) Have some form of quality control in place, even if you’re not targeting Passivhaus, to get the results you’re expecting

    Find out more

    Passivhaus Trust

     

    Transcript

    Download a transcript of the interview with John Palmer

    Please connect with us

    Subscribe, rate and review us on Apple Podcasts

    Like our Facebook page

    Follow Ben Adam-Smith on Bluesky

  • HPH142 : What is a Passivhaus Designer? – with Marine Sanchez from Enhabit

    HPH142 : What is a Passivhaus Designer? – with Marine Sanchez from Enhabit

    Marine Sanchez from Enhabit explains the role of a Passivhaus Designer.

    Marine Sanchez 03

    Interview with Marine Sanchez

    Marine studied general engineering at university before completing a Masters in sustainable buildings. Realising that buildings weren’t performing the way they should do, she studied further to understand the performance gap, which led her to Passivhaus. As well as being a Certified Passivhaus Designer for the last four years, she is a building physics engineer and now also teaches others who are studying for the Passivhaus Designer qualification.

    Being a Passivhaus Designer is about understanding the physics of how a building works

    Training to be a Passivhaus Designer involves an intensive two week course. Marine says that they get quite a range of people, from architects, structural engineers and mechanical & electrical engineers, right through to a few brave self-builders! At its core is a lot of maths and physics to really understand how a building works. There are two qualifications from the Passive House Institute in Darmstadt – Passivhaus Designer, and Passivhaus Consultant. Marine explains that there is very little difference between them, and it is just a matter of what type of degree you did at university.

    Beyond that, there are independent Passivhaus Certifiers who will review the design and advise whether the building can be certified, and Passivhaus Tradesperson who are the people on site that are trained to work on low energy buildings.

    A Passivhaus Designer guides the whole design team as to the concepts that are being worked towards

    Ideally a Passivhaus Designer would want to be involved from the start of the project, so that the low energy aspect is not a costly constraint on a design that is brought to them much later. Being involved early on means they can guide the design team, including the client, through the early feasibility stages on what type of concepts you want to work towards. Any changes on a design can have an impact on how the building will perform, and as the Passivhaus Designer is the one to make promises on that, they need to have an overall view and understanding of what everyone on the team is doing.

    Marine explains that it’s easier if everyone on the team has Passivhaus experience, but even if they don’t the standard can still be achieved if a Passivhaus Designer is involved. It might make it a little more challenging and time consuming, but would be a good learning curve for everyone involved! What is important though is that everyone buys into it and works proactively as a team.

    © Paper Project Architecture and Design
    © Paper Project Architecture and Design

    © Paper Project Architecture and Design
    © Paper Project Architecture and Design

    Passivhaus Designers might be approached through an architect or directly by a client

    If they are approached by an architect then they will often find themselves working in different teams on each project. If a client goes to them directly however, Marine explains that she would suggest three or four architects they have liked working with previously, and leave the decision to the client, based on the type of architectural style they might be looking for, and who they feel they could interact well with.

    If you’re looking for a Passivhaus Designer you will find them all listed on the Passive House Institute website, but because the Passivhaus world is quite a small community you may find names cropping up once you start talking to people and doing initial research.

    A typical week for a Passivhaus Designer…

    Any week is likely to be a combination of a few different tasks. They tend to be:

    Desk-based work – such as modelling using PHPP (Passivhaus Planning Package), thermal bridging calculations and moisture transfer modelling, to assess how a building is going to perform.

    Project team work – part of the week will be dedicated to interaction and team work with the rest of the design team, so architect, structural engineer, quantity surveyor, client etc.

    Site visits – this provides the opportunity to ensure that the designs are being implemented on site, support the builders in understanding the concepts that are being asked for, and checking and testing the design.

    Owner / architect case study

    Enhabit are currently working on a project where the architect is also the owner and has undertaken the Passivhaus Designer course. He and his wife had already had an architectural concept design but approached Enhabit for support in terms of insulation strategy etc.

    ©Paper Project Architecture and Design
    © Russel Hayden

    From that stage they did a feasibility study, where even if they didn’t know all of the details they had a good idea of what was going to be required so could make it work in PHPP to give a performance specification.

    A detailed design process followed to make sure that each performance for every element was being met according to the targets set. All of these elements are refined and finalised before going on site.

    This particular project is now on site and they are currently working on the roof insulation.

    © Russel Hayden
    © Russel Hayden

    Don’t rush the design

    This would be Marine’s key piece of advice:

    “If you want a low energy building it will take a bit longer to design. It’s okay but I think that if people don’t rush it through design and really get it right, I actually think that your build goes so much smoother. And it could potentially go quicker as well because you don’t have to sort things on site and things you haven’t thought of, or compromise on the target that you wanted, which is what happens when people don’t actually work enough on the design before going to site.”

    Find out more

    Visit the website of Enhabit

    Follow Marine Sanchez on Twitter

    Transcript

    Download a transcript of the interview with Marine Sanchez.

    Please connect with me