Our Next Big Adventure
I grew up with parents who loved doing up old houses to make them better homes for our family and this is a legacy that Ower Dave and I have carried on and, in turn, so have our daughters First Born and Last Born. Himself and I have completely renovated two houses of our own and helped other people on countless others...it's what we do. Well, I don't do electricity, but apart from that I'll try my hand at anything - I particularly enjoy a good bit of demolition and have a smaller, lighter-weight lump hammer that serves me very well! We know about old houses, we understand old houses and have always said we would never live in a new house......unless we built it ourselves.
This is because modern house building in England is totally dominated by several countrywide building companies who build big housing estates of identical houses very badly. They effectively block Government changes to better insulation in houses, never fit mechanical ventilation and heat recovery systems, rarely fit solar panels on roofs, lie about gas central heating boilers being more effective/efficient than air source or ground source heat pumps or claim that they should still be in use because they are 'hydrogen ready' ...... even though the method of producing enough hydrogen doesn't even exist yet! *Liz climbs back down off her soapbox at this point before she gets carried away with her disgust at the big builders*
Their business model is to build as quickly and cheaply as possible in order to maximise their already vast profits. This 'chuck'em up and sell 'em quick' approach results in shoddily built, poorly insulted, damp houses which are expensive to run and NEVER meet the energy use targets the profiteering builders claim they will. The energy usage can by as high as 70% more than the builders claim it will be because the building is never tested during the build process and most of the corner cutting to keep cost down is done on all the areas that are covered up - things like the points where the walls and floor meet not being sealed or saving pennies on insulation boards by not butting the boards right up to each other, resulting in 'thermal bridges' between the boards where cold can get in. The poor build quality and the performance gap between design and in-use energy performance is shocking, but they're still getting away with it. Wonder why? Friends in high places perhaps?!
Note: The 'Performance Gap' is the difference between the actual heating demand and what was predicted at the design stage.
However.....during Lockdown in 2020, remember that very weird time?! Unbeknown to me, Himself had somehow wandered across some information about Passivhaus buildings online and started quietly delving deeper into it. Eventually, in late Autumn of 2020, he presented me with the fully formed idea that we should sell our beautiful house and build a Passivhaus! To say I was gobsmacked was putting it mildly!
I had always imagined that this house would be our 'forever home' even though the realistic Occupational Therapist in me knew deep down that it wouldn't actually be a good house for our older age as it would be impossible to future-proof it without loosing its delightful character ...... but I definitely wasn't at the point of considering moving, let alone building a house and even less ready to build something I'd never even heard of!
Himself was somewhat surprised and not a little miffed that I didn't instantly dance a jig around the kitchen in joy and excitement at his idea - until I pointed out that he'd obviously been thinking about this for months and had just dumped it on me as a fully fledged plan without any preamble or warning! We then agreed, him somewhat reluctantly as he was itching to get started, that I needed time to process what he'd told me and to do some Passivhaus research of my own as well as getting my head round the possibility of leaving both my beloved home and uprooting myself from a town I enjoyed living in and where I had friends and an active social life, to go somewhere as yet undetermined to not only build a house but to start from scratch to build new friendships and community.
It took me about 3 months of researching and soul searching to feel that this was something we could do and to feel confident enough that we could actually manage the process without murdering each other or ending up divorced!
What is Passivhaus?
The Passivhaus concept was developed by Dr. Wolfgang Feist back in the 1970's and 80's when he realised that over one third of fossil fuel energy consumption was being used to heat buildings! As a physicist, it was clear to him that there had to be a better way to heat houses, reduce the heat losses and avoid creating damp houses .....so he set about to find a reliable procedure to depict the thermal behaviour of buildings. This all led to the development of the Passivhaus standard.
The Passivhaus Standard
Passivhaus is a suite of performance and comfort standards for buildings that reliably deliver energy efficiency, comfort and quality. There are three core principles in the integrated approach to designing a Passivhaus, which are:
- Detailed performance and comfort criteria
- Modelling each project using the Passivhaus Planning Package (PHPP) More of this later
- Rigorous Quality Assurance and Passivhaus Certification
The Passivhaus Trust defines five Passivhaus Principles to give a project-specific solution. These are:
- High performance insulation which is optimised for comfort, energy demand and the climate zone of the specific build
- Use of a continuous high performance airtight layer to minimise heat loss, eliminate draughts and maximise fabric longevity
- Minimised thermal bridging to prevent cold spots and mould
- High performance window specification and shading to provide optimum comfort and efficiency in summer and winter
- Quiet and efficient Mechanical ventilation with Heat Recovery (MVHR - more of this later too) to deliver high indoor air quality
In short, a Passivhaus is a robust and well-built, eco-friendly, highly insulated, draught-free, cheap to run box with good quality ventilation and which remains at the right temperature year round.
Each house is individually modelled for its latitude, longitude, altitude and orientation in order to maximise performance and minimise overheating risks in summer. It is also tested for airtightness several times during the build process - this doesn't mean you can't open any windows,of course you can, it just means it's thoroughly checked to ensure there are no draughts or cold bridges anywhere, has proper ventilation and the correct amount of air changes per hour to achieve high quality indoor air.
AND.....if the house passes all the tests and achieves Passivhaus standards, you get a little plaque to put on the outside of your house! What's not to like?!😀
If you want more information about Passivhaus (which I hope I've piqued your interest enough to do) here is the link to the website. The Passivhaus Trust
Follow the link then click on 'About Passivhaus' on the home page. Mind you, the whole website is interesting and will help you understand where we're coming from and why it appealed to us - and I guarantee you'll never look at other building methods in quite the same way again!
Of course whilst I was doing my research, Himself was avidly reading anything he could lay his hands on about Passivhaus - such as The Passivhaus Handbook.... The Passivhaus Bible, as it became fondly known as in our house - which, as a 1920's single glazed, very draughty house, was anything BUT Passivhaus!
I have read it as well, but Himself knows it so well he can practically quote from it!
So...having been converted to the idea of building our own Passivhaus, we moved to Stage Two.
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