Categories
Construction

Learning from Passivhaus Building

The people of Green Building Store (UK) have generously produced and published a freely available online movie about some of the challenges they faced in a Passivhaus construction project in the UK. Though I am wary of taking on the Passivhaus standard as is (reservations I’ve written about in posts about Passivehaus and Rural Studio) I am also trying to be careful not to pour the baby out with the water. There is a lot of common sense in Passivhaus and much of it is excellently communicated in this movie. You can view all the parts here or possibly start with this embedded video and then continue to each consequent part:

So, with much curiosity and interest I watched the movie (reviewing some of the chapters numerous times) and made some notes of things that I hope to incorporate into our building process. This list does not include the core-issues of Passivhaus construction (insulation, minimal thermal bridging, air-tightness, ventilation and passive solar gain) which deserve careful context and consideration – especially when it comes to hemp-lime construction which introduces unique qualities to both the construction process and the resulting structure.

Design & Details

It is invaluable to spend time designing and paying attention to details before the actual construction process. Construction is an established process and skill which carries with it a taken-for-granted attitude. Professionals have a way of doing things and will prefer to do things the way they’re used to doing them – which may lead to cutting corners in design and to on-site improvisation.

This can be destructive in a project where new standards of building, new materials and new techniques are involved. Taking the time to plan things in advance, to drawing diagrams & making calculations creates a thoughtful path towards a desirable result. Of course it is inevitable that unforeseen challenges will arise during construction and that some changes and improvisation will be required – in which case a plan gives some indication of how far you’ve deviated and what you need to do to get back on track.

Special attention should be given to details. I’ve been working on a wall-to-floor detail for weeks – compiling all the information and knowledge I have come across, reconsidering it in the context of hemp-construction, our house design, minimizing costs, minimizing the use of concrete and relying on locally available materials. There is no ready-made template for what we are doing, there are many options to choose from, there are many considerationt to incorporate. We could take the easy path and hire foundation contractors and let them do their thing – but that would lead away from the kind of warm, pleasant, ecological and efficient house we hope to live in and bring us to the standard cold and humid house that contractors have been building in Romania for may years.

Team Work

A typical construction process tends isolate and compartmentalize knowledge and skills. We would consult with an architect to design our house. Then we would pass the plans to an structural engineer who would need to figure out how to support our house. Then we would pass the architectural and structural engineering plans to a heating engineer who will try to provide an adequate heating solution within the existing constraints.

This kind of approach can lead to an inefficient process and an inefficient house. A good engineer can provide a structural solution to meet almost any need – but at what price? How much extra work, materials, construction effort and waste may be required to implement the engineered solution? Similarly a heating engineer can theoretically heat any space – the question is how expensive and complicated will the system be and how much energy will it consume? This is a brute force approach.

We are trying to put together a team that will work together during all phases of the project. We’d like everyone to be there to provide input at every stage of the project. We’d like the architect to provide input on choosing good land and on siting of the house on it. We’d like the structural engineer to make suggestions on architectural decisions that may lead to simpler and more efficient construction using less materials. We’d like a heating-engineer to review the size of our spaces and to make suggestion that may improve the energy-efficiency of the house.

It takes integrated and out-of-the-box thinking to create the kind of integration that leads to a house that facilitates an “eco” existence.

Opening Details

I have been wondering about how to go about properly insulating openinsg like windows and doors. The movie offered some very useful tips about these issues and these are the ones I noted:

  • Windows should be placed at the center (depth) of the wall.
  • Windows should open inwards – placing the thicker part of the frame on the outside for better insulation.
  • Special sealing tape (such as Pro Clima Contega FC) should be applied between the rough structural opening and the internal wall and then covered by the the internal render.
  • Special sealing tape (such as Pro Clima Tescon) should be applied between the window frame and the rough structural openings.
  • A concrete slab should not extend to the door opening to prevent heat loss through it.
  • The door opening slab requires an insulated and weather resistant material (such as fiberglass).

A big thank you to the people at Green Building Company. This movie has been very educative and helpful.

Categories
Energy Heating

Heating Resources

We want to have a really pleasantly warm house when it gets cold outside. Building with hemp insures that we enjoy a wonderfully insulated home. Now we need to deal with heat – which includes both environmental heating and water heating.

In typically built houses which tend to be cold when it gets cold outside it’s more a brute force challenge. With an ecological house it is actually more complicated because it’s easy to design a system that overheats the house. We still don’t have a clear picture or understanding of our heating needs – though we are working at it.

In the meantime I wanted to share with you some great resources that we are using to educate ourselves:

  1. Stoves Online (UK) – it s great resource for learning about the different elements that make up a heating system with a very rich offering of solutions if you happen to live in the UK.
  2. Boiler Stoves (UK) – seems like a sister website which specifically explains how boiler stoves work and can be incorporated into a smart and efficient heating system.
  3. Radiant Design Institute – though not an appealing website has a lot of really well-grounded and useful information I believe can be very useful especially to do-it-yourselfers.

You may also want to visit these two pages:

  1. An animated demonstration of a boiler-stove at work
  2. An article that debates whether radiant-floor-heating is at all appropriate in well insulated eco-buildings
Categories
Construction Hemp

Look Out Romania – Here Come’s Hemp

We aren’t the only ones trying to do this … as I write these words Andreea is making calls … this is so happening 🙂

… this is Teodor Pop of Lux Perennial
… which are associated with Hemp Technologies USA
… which are associated with Lime Technologies UK.

Categories
Construction Wood Framing

Learning to Read Plans

I’ve been spending the last few weeks immersed in reading about wood-framing. I’m really enjoying the experience of feeling that it really is possible to self-build a home. It’s logical, straightforward and building with hemp simplifies it even more.

I recently came across these sample PDF plans of an eco-house from Studs – a UK timber frame design company. I am happy to say that it isn’t all giberish to me anymore 🙂 I still can’t read it all – and some parts are a bit overwhelming – but I think it’s good practice to start looking at such plans. They provide house design ideas, they teach structural lessons and they prepare you to communicate with other professional which we expect to be doing.

Categories
Construction Hemp

Modece Architects

It’s been over a week that I’ve had the website for Modece Architects open in my browser. I really enjoyed the website – it feels like an authentically green site – one that actually walks the walk. Particularly I’ve browsed back and forth endlessly in the sustainable-construction gallery which has been quite an eye opener. For example …

This image hints at the potential of using quality timber framing together with hemp construction – which I was just wondering about…

or this image that demonstrates that loose hemp!!! can be used in floor insulation:

… or this image of a do-it-yourself solar panel:

… honestly, every picture in their gallery is like a magical doorway into knowledge.

But what really tickled my fancy was that as I was revisiting that must read book on hemp-lime construction I recommended a while back – I made the connection that the hand-drawn illustrations starting on page 31 were contributed by Ralph Carpenter of Modece Architects … and I am thinking “yeah, that’s the website I’ve got open in my browser” … so it seems that the world of hemp-lime construction is still a nice and intimate community 🙂 Great fun!!!

Categories
Energy Heating

House Heating Requirements (revisited)

IMPORTANT: this note was added after the post was published but seemed important enough to be inserted at the beginning of the post. I am just now realizing that my perception of heating requirements are based on experience of poorly insulated homes. This is why I expect stoves to be lit numerous times a day. But, in a properly insulated home the need for heating should eb drastically reduced. If this is true – then all our elaborate plans to use stove-heating may be irrelevant – since the stoves may not be lit long enough to generate hot water. Having a super-energy-efficient home may lead to us to simpler, existing ready-made solutions. We don’t know, and we don’t know yet someone who knows … so for the time being it’s all up in the air.

Some weeks ago we described an imaginary-heating system and since then we’ve come across numerous resources and refined our understanding a bit.

I think there are two core ideas that shape and guide our understanding and wishes of a heating system:

  1. Most of the time we can shower when hot water is available – though it’s comfortable we don’t really need hot water to be available on demand.
  2. Enough direct heat is generated by our wood-stoves to indirectly supply most if not all of our heating needs.

So what we can say about our envisioned heating system?

  1. It will be an integrated water-based system – the same systems is used to generated running hot water and water for a radiant heat system.
  2. The system relies as little as possible on electricity – we would like to have a warm house and hot water even during a complete power-out (though it may run better when powered with electricity).
  3. The system will include an indoor cold-water container that will bring the water to room temperature.
  4. The system will include a central hot-water tank (not a boiler!) that supplies both the radiant heat water and flowing hot water to facuets and showers.
  5. The primary source of heat will be classic Romanian-village-style terracotta wood stoves. We expect to have one or two primary stoves in the living-space and kitchen. We both work from home a lot and cook a lot so these stoves will already be working.
  6. We would like to design and build the wood stoves to include an efficient coiled water pipe that is connected to the radiant heat water circuit and feeds back into the central hot-water tank.
  7. We would like to install a on-demand gas water heater on the running water hot-water circuit as a backup in case the water in the hot-water tank is not yet hot enough.

Following are someuseful web-resources:

Categories
Construction Wood Framing

Timber Framing

Introduction

A few weeks ago when I began exploring the world of framing it (and I) was dominated by a fairly straightforward technique of wood-framing – using standard 2×4 lumber with nails and metal connectors to construct a home frame. But then I came across a blog where someone spoke of another building method – one that relies on creating elegant joints between wood joints that are fastened together with wooden pins (kind of like huge nails) – an all wood structure.

I encountered all kind of terms I didn’t know like dovetails and tenon joints. So I did some more searching and came across this abundant resource that had way more information then I could possible want about techniques for joining together pieces of wood. I discovered an entire art of wood-joints … which actually blew the wind out of my sails. I thought that was just too much to attempt to muster on a project with limited time and resources. So I set it aside.

Timber Framing

I am now entering a second round of inquiry into wood framing – the straightforward “nail and connecing plates” kind this time going into more detail. Then, a  few days ago I came across Northern Lights Timber Framing and a single image on their home page blew my mind. This is what timber-framing looks like:

Most of the structure (except for some of the supports) is made from massive timber beams that are crafted into a carefully planned puzzle. There is an entire carving process that takes place away from the building site during which all the pieces are meticulously crafted and tested. Then they are brought to the building site site and with the help of cranes, assembled into a monolithic structure. It is an artful process shimmering with quality and inspiration. It is very different then wood-framing. Here’s another images from Northern Lights – this time an indoors view of a timber-framed house:

The Northern Lights site listed a link to the Post n Beams blog, written by a student that trained with the folks of Northern Lights. It is a great and informational blog to read with excellent, detailed and informative images. This images from the blog further demonstrates the elaborate art of Timber Framing:

This is very different from wood-framing:

We Will Probably Build with Wood Framing

From where I stand now I am somewhat sad to say that we will be building our house with wood-framing and not with timber framing. There are a few reasons for this:

  1. The overall framing process, as I understand it, seems to be more complicated and longer then wood-framing.
  2. It seems like a more expensive building method (tools, materials).
  3. It requires refined skills and workmashinp – making it less relevant as a do-it-yourself project.
  4. Most of our wall-framing will remain hidden from sight as it will be emdedded inside the hemp-lime walls.
  5. Hemp-lime masonry needs studs to support it.
  6. Except for a living-kitchen space, energy concerns are leading us to smaller more heat-efficient spaces – so the benefit of an open-floor structure are marginal.
  7. Most of the roof will also be highly insulated with hemp and other materials.

Yet …

I would love to incorporate into our building process some of the qualities of timber-framing. There is more to it then meets the eye. I wonder if, for example, similar joint techniques can be employed when framing with 2×4 lumber?

I am no expert but my instincts tell me that timber-framing delivers a superior structure (to that of wood-framing) and the fact that it is all-wood (no chemical interactions with metallic parts) give it a better shot at longevity (though in our case this may be mitigated by the hemp-lime encasing).

A part of me hopes that we come across a magical local timber-frame builder that will change my mind 🙂 I would love to live in a structure that was built with such masterful craftsmanship.

Categories
Blog Pondering

Rural Studio

In a way this post continues my previous post on Passivhaus. I’ve had these resources open in my browser for some time and didn’t quite not in what context I should place them here on Bhudeva. Passivhaus gave me to the context that was looking for me.

Rural Homes is a project run out of Auburn University in Alabama, USA. We learned about it through Itsik Hirsch – a talented architect and teacher at the Israel Institute of Technology who also happens to be a dear person to us and my uncle. Itsik teaches what is called “studio” – which, as I understand it, is an experimental learning space which usually makes up a major part of architecture studies. It is where students do actual architectural work and gain precious practical experience. But in most cases that experience remains theoretical because their projects are not actually built.

The Rural Homes project took the “studio” in an inspiring direction. In it students are challenged to create feasible and affordable solutions for people who live in extremely poor living conditions. The challenge is not just to create a design on paper, the students actually go out and build the house themselves. It is a tremendously inspiring project that touches many people’s lives. It is a wonderful (and in my experience rare) example of academic study and research directly connecting to and benefiting the society in which it exists.

Following is an interview with the man behind this beautiful project – Samuel Mockbee:

For more information:

So what does Passivhaus have to do with all this? Very little and that is the essence of my critic of it. Rural Studio should be a reality check for Passivhaus. The greatest place for impacting both the lives of both people, the environment and this entire planet we inhabit (which are really so intertwined to the point that they are one and the same) is where most of the people are, not where a small percentage of rich people can indulge in ideology.

Our reality is somewhere in between Passivhaus and Rural Studio. I am inspired by Rural Studio and deterred by Passivhaus. I feel that Rural Studio touches my life and that Passivhaus overlooks it. Maybe I am bit too harsh towards Passivhaus and though I can speculate on why that is I will keep that to myself – it is a question I believe Passivhaus can benefit from asking.

The Rural Studio from BluePrint Productions on Vimeo.

Categories
Construction Hemp

Passivhaus

Introduction

Passivhaus is one of the terms out there in eco-green-sustaintable building land. It may look like its spelled wrong but that’s because its originally from Germany. It represents a very strict and high standard of energy efficiency in a building. It isn’t (yet) an official requirement or standard but it is gathering momentum as an unspoken standard.

There are three complementary core ideas behind the idea of a Passivhaus:

  1. Complete and thorough thermal insulation of the house which prevents conductivity of heat from the inside-out or the outside-in.
  2. Complete air-tightness which prevents exchange of heat through air leaks (windows, doors, pipes, chimneys … every opening needs to be sealed!).
  3. An efficient ventilation system that both exchanges air (from the outside and the otherwise airtight house) and does so without losing heat.

This is one of those images that is better then a thousand words. The apartment building on the left is standard/traditional building while the apartment building on the right is built according to the Passivhaus standard. That’s the bottom line of Passivhaus – keeping the heat from escaping means you need to expend less energy to heat the inside.

Extreme!?

I have come across Passivhaus numerous times in recent weeks and my recurring personal impression is that it is too extreme:

  • It seems like more of an academic indulgence then a practical construction practice.
  • It’s objective and success is measured in a single number – the amount of energy needed to heat a square-meter of space.
  • It demands rigorous builing disciplines which require uncompromised excellence in construction.
  • It demands the use of specialized insulation materials which can be expensive (especially if you consider the ecological foot-print involved in manufacturing them).
  • It creates a house that demands constant attention, maintenance and proper use by its residents (every window opened and every hole drilled in the wall is a potential energy hazard).

All of which results in a delicately balanced system: if it isn’t absolutely sealed, perfectly ventilated by a carefully installed system and properly used it just won’t work. There is no room for error. This maybe OK in a scientific experiment but not so for life, nature and people.

In any case it doesn’t feel right for us: we have a limited budget, average construction capabilities, standard building materials, etc. We are going to do the best that we can with what we have. It’s an 80/20 kind of thing – where 20% of the effort takes you 80% of the way you need to go and it would take another 80% of effort to go the rest of the way. We’re aiming for a good middleground – pushing the limits of what we have – but that, by definition, is not enough to go for 100%. Passivhaus is uncompromising, but we live in a reality which demands compromise.

“A passivehouse is cost-effective when the combined capitalized costs (construction, including design and installed equipment, plus operating costs for 30 years) do not exceed those of an average new home.”

Source: PassiveHouse.com

I am hesitant to relate to this statement as that may give it unwarranted legitimacy –  cost is just too narrow a perspective to view ecological housing. But if I do meet it head on, as is, I would say that it sets its sights much too low. I hope to build a house where the combined capitalized costs are much lower then those of a new average home (whatever that is). I also hope to build a house who’s qualitative effects (both for us and others) far outway it’s economic effects.

Maybe Passivhaus is, for the time being, a high-end building experiment? Maybe in time it will spawn accessible, affordable and feasible techniques, solutions, technologies, practices … that can become a defacto standard that simply makes sense to follow? For now, it is out of touch with us and our needs.

Humidity

Having said all that exploring Passivhaus has brought to my attention a factor I had not taken into consideration in all of my energy research: Indoor Air Quality. I have been following a very basic intuition: “generate heat” in trying to solve a problem we’ve been having for many winters: “being cold”. Most of my attention has been on how to preserve and generate heat (space and water) effectively.

I had not given any thought to one of the central themes of Passivhaus: quality of air. Quality of air (assuming there is good ventilation) is strongly effected by humidity … and humidity effects the overal experience of temperature … cold is much colder when humidity is too low and heat is much hotter when humidity is too high. I have experienced the effects of humidity in warm and cold temperatures in Israel and I have seen it (as accumulated moisture and mildew) in almost all Romanian homes I have visited.

I don’t know yet enough about ventillation and humidity.

Hemp

One of the much praised qualities of hemp masonry is it’s breathability. It seems to have a natural tendency to absorb and expel unneeded moisture. I don’t yet have enough information on the overall effects of hemp on moisture, ventilation or quality of air indoors – but I do have a good feeling about the effects of hemp!

Resources

Following are some of the resources I came across and consumed in trying to understand Passivhaus:

Categories
Construction Hemp

Interview with Ian Pritchett of Lime Technology

So pleasing to see a pleasant person who loves and believes in what he does. An interview with Ian Pritchett, Managing Director of Lime Technology: