What’s up with all these tubes?

Tubes!

The tubes are conduit runs through the foundation.  This is a photo of the concrete forms.  Concrete will be poured into the forms to create the foundation walls.  The tubes provide a chase for things to be run up into the unit – wires, pipes, etc.

Seems like a lot of tubes, right?  We have a lot going on in these units – regular stuff like water pipes and electricity, but in our case ground source piping, extra wires for the solar panels…and who knows what else?  So we have a lot of tubes.

BedZED – solar atrium elevation

BedZed sits like an island in the south London suburb of Beddington (BedZED stands for Beddington Zero Energy Development).  The day I visited it, I did the long walk from the local train station, along a fairly busy, not very attractive arterial.  Suddenly, there it was – a sort of Earthbound naturalistic UFO set amidst the dreary backdrop of run of the mill flats and commercial buildings.

BedZED is mixed housing/office development, with about 100 townhome units and about 13,000 square feet of offices.  But that benign, run of the mill description doesn’t really give you any sense of it.  My visit to BedZED is perhaps the single most hopeful day in my life, environmentally speaking (except for my visit to Hockerton – more on that later).  BedZED is one of a handful of buildings planet-wide that has what is at least close to a truly sustainable footprint.  Like zHome, BedZED established a number of environmental benchmarks, shown below, along with how well they’ve actually performed (the community was completed in 2002). What BedZED shows us is that radically more sustainable buildings are possible, and within reach now, not some indeterminate time in the future.  Here is a chart of the environmental specifications for the project, along with how it’s actually performed:

The energy component of BedZED is what I think is most compelling, and I am really taken with the technologies they used.  What is most interesting to me is that many of them are completely different from zHome, even though the climates are quite similar.  This gives me a lot of hope because it says there are a lot of technological pathways to achieve zero net energy/carbon buildings.

BedZED starts with the same hyper-insulated wall section that zHome does – that seems like a basic constant in our climate.  But BedZED uses masonry (brick and concrete) walls – typical of European residential construction – rather than wood stick frame.  BedZED has also wholeheartedly embraced passive solar heating of the homes, with a solar atrium sitting on the south side of the homes, unlike zHome.  This solar atrium has glass with a high solar heat gain character, allowing it to heat up dramatically. Once this atrium has warmed up toward the end of the day, the residents open an inner set of highly insulated triple paned French doors to allow the heat into the units. This solar heating provides the majority of the required heating for the units. Hot water, and supplemental water based hydronic heating, is provided by means of a combined heat and power unit for the whole project. This is essentially a large boiler with a turbine attached to generate electricity. This system was designed to run off wood waste, but when I was there it was running off of natural gas. The passive solar heating system heats the homes well enough to only need one heating element in the homes: a heated towel rack!

Combined heat and power building

Where are your priorities? Heated towel bar

My favorite view of BedZED is across the soccer pitch, with BedZED, and a neighboring project which was built at the same time, in view next to each other. The BedZED architects (Bill Dunster Architects) nicknamed the neighbor BedHED, for Beddington High Energy Development. It’s a pretty amazing image – two projects, built at the same time, with the same essential building structure and technology, but one which uses radically less resource and emits radically less CO2. Smart, thoughtful design, coupled with innovative technologies got them there – Yes they did – and Yes we can! (Forgive me, I couldn’t help myself, it’s Inauguration Day tomorrow).

BedZED and BedHED

Here is a link to the official BedZED website.

zHome is being built in accordance with stringent environmental benchmarks.  These are actually contractually established between the City of Issaquah and Howland Homes.  You can  read the benchmarks here if you would like to delve into these further (all 14 pages of them!).  You can see for yourself exactly what design criteria have been established for the project.   

So why benchmarks?  To me it goes back to the graph shown on the Why Green Homes? portion of the site.  In big picture terms, zHome is about looking at the cold hard numbers of building’s hefty environmental impacts, and taking those numbers as close to zero as possible.  There is something pure about a numeric driven design process:  set your goal, and let the design process figure out the most efficient way to get there.  It’s not that dissimilar to a gas or carbon tax – get aggressive, and then get out of the way and let the people involved figure out how to respond.  I also think there is something powerful about giving a number to what you’ve achieved, as opposed to some more qualitative measure – I think your average person can get it better.

And then there’s accountability and integrity.  The zHome benchmarks are all subject to verification by the City.  In some cases our other partners are involved in this process as well.  For example, Howland Homes’ energy model (done by Stantec) has been vetted and reviewed both by the City and the WSU Energy Program.  We feel that if you’re going to make strong claims (such as the project is achieving zero net energy), there should be integrity and transparency behind those claims.  Very few of the projects that are claiming zero net energy have actually undergone energy modeling to verify the claim, and fewer still have been verified by outside parties.  And many projects and builders that use the term “zero energy” are actually talking about it conceptually, in terms of it simply being a goal or good idea, or being part of a long term program to achieve zero net energy sometime in the future.  I feel that that dilutes the power of the name because it implies this very difficult goal is being met regularly.  Certainly our goal should be zero energy, but when it comes to individual projects, zero energy terminology should be used carefully and transparently.

Sensible House

I have come to believe that innovation rarely occurs in a vacuum, with a mad scientist coming up with something that noone else could see or envision.  Even with radical jumps in design, there are prototypes, predecessors, and context.  We all stand on each others’ shoulders – there are very few if any islands out there.

And so it is with zHome.  In particular, there are several of specific zero energy or close to zero energy projects that inspired it – specifically, the Sensible House in Seattle, and BedZED and Hockerton in England.  I want to highlight each of these projects, and this will be the first of several posts on this subject.

Jon Alexander, Builder, Sensible House

The Sensible House was built by a friend and mentor of mine, Jon Alexander of Sunshine Construction.  Jon is one of the very earliest builders in Seattle to get involved with green building, and is truly a pioneer.  He began thinking about and applying principles in the 1980’s.  He is also one of the founding members of the Northwest Eco-Building Guild (www.ecobuilding.org).

The Sensible House was built as a personal residence for Bob Scheulen and Kim Wells, who were directly involved in its design and construction.  Bob himself has had a long time interest in green building, and maintains a great web site  dedicated to the house and how it works.

I first visited the Sensible House just as it was finishing construction about five years ago.  It remains in my mind as one of the greenest, if not the greenest single family home in the Seattle area.  It includes double wall construction, a structural insulated panel roof, very cool triple paned windows from cold Alberta, as well as a hybrid water based heating system with solar hot water pre-heating.  According to a presentation that Bob gave a couple of years ago, the house isn’t quite achieving zero net energy – but it is darn close, within 15% of zero or so.  Lots of neat green materials are included throughout the house as well.  The web site is a great technical resource, and Bob has added additional information about the home over time.

I was in awe of the house when I first visited it, and continue to be – it is a very early pioneer locally of ultra-sustainable housing.  It is safe to say that the Sensible House is a direct inspiration and parent to zHome.  I want to recognize and honor Jon, Bob, and Kim for their trailblazing in green, low carbon building – without you and other projects such as BedZED, zHome would have been much more difficult to envision and design.

Think about just about any industry – telecommunications, computers, aerospace, heck, even automotive – and the list of innovation and progress over the last 100 years is long.  Think about where all those industries were 100 years ago – the state of the art for those industries were:

• -crank telephones through a community switchboard
• -mechanical adding machine
• -the very earliest airplanes (Wright Bros. flight was in 1903)
• -Ford Model T (prototype 1908)

How many of those pieces of technology are actually in use today, without massive improvements?

Then consider housing.  The history of innovation in housing over the last century and a half is short, and a lot of it happened a LONG time ago:

• 1833    Stick framing invented
• 1920s  Beginnings of widespread home electrification
• 1930s  Forced air furnaces introduced
• 1940s  Basic insulation mandated by code
• 1970s  Double paned windows become standard

The house we live in was built in 1925.  Its tiny garage is sized to fit a Model T (or, a Smart Car!).  When I look at our house and compare it to a new one, it’s not all that different – the rooms are smaller, there was no insulation in the walls until five years ago, at some point along the way the coal burning stove was replaced with forced air, and it has single paned windows.  But really, that’s it. 

I don’t think that an “innovation is a priori good” stance is a reasonable, don’t get me wrong.  Thinking about Christopher Alexander’s A Timeless Way of Building, I think there’s a strong case to be made that the materials and methods that stand the test of time are a good way to go.  Heck, even in zHome we are making the case – particularly in the world of materials – where we are even harkening back thousands of years and finishing some walls in clay. 

For me the core issue is that we think about what we’re doing.  To me the home is the lowest hanging fruit of potential environmental innovation.   Homes are so core to who we are, and their share of our environmental footprint is so big, that a concerted reevaluation of what home is seems in order.  Through that process, I think we’re likely to find that some of the answers lie far in the past, and others in the untapped future.

Rainwater system team in action!

Last week we brought parts of the design and permitting teams together to work through the final details of the rainwater catchment system. It is one of the very last details to be resolved prior to approval of the building permits. I thought the discussion was an interesting example of process and evolution in the design process. Participating were Dennis Rominger, Howland Homes project manager; Mark Weirenga, project architect from David Vandervort Architects; John Minato, City of Issaquah Building Official; Sylvia des Rochers, City of Issaquah plans examiner; Doug Schlepp, City review engineer; Mark Buehrer, system design engineer with 2020 Engineering; and myself.

The design team proposed a very simple, elegant system for rainwater recycling. Water from the roofs flows into a gutter and downspout and then directly into a cistern (one for each home). Rainwater is then pumped into the homes, where it is placed in a pressure tank, where it then is used in toilets and clotheswashers (I am skipping over many details which will be covered in a later post). In the event that the tanks run dry (unlikely, but possible during a very dry summer) they could be manually refilled by the residents with a hose.

The permit review team’s comments focused mainly on health and maximizing water conservation. To maximize the safety of the system, the design team proposed plumbing the potable and rainwater systems completely separately, so that non-potable water would not be cross contaminated with non-potable water. But to be completely belt and suspenders in terms of safety, the permit team suggested a number of additional measures. First was a backflow prevention device on each unit’s individual water line, so that in the unlikely event that someone at a future date replumbed the homes and mistakenly connected the potable and non-potable systems, that contamination could never enter into the public system. Second, routing of the lines will be done carefully so that potable and non-potable lines are not adjacent. Furthermore, non-potable lines will be clearly labelled at frequent intervals that it is non-potable water.

A lot of attention was given to the refill process for the cistern. The permitting team was concerned that during drought refill, that the hose might be tossed into the cistern, and that however unlikely, a backflow might occur, pulling non-potable water from the cistern into the hose and into the potable system (of course, a very rare occurance). There was also concern that residents might leave the hose running longer than necessary and fill the entire cistern with potable water, rather than a small amount needed to tie the resident over to the next rainfall. Initially the permitting team suggested an automated refill system that would add potable water into the system when it ran low. An air gap would be provided on the refill, to ensure non-potable water couldn’t be syphoned into the potable system.

However, the design team didn’t like the potential of that system breaking down, and also didn’t like the hands off feeling of the automated system – they wanted the residents to be in touch with their system, at least to some degree. So both teams synergistically developed a new idea – a timed manual refill from within the homes, plumbed with an air gap into the downspout system. Physically, it will be impossible for non potable water to be syphoned into the potable system. And the timer will ensure that refilling is limited to that needed for a couple of laundry loads. It is nearly a simple as the original design, keeps the residents connected to their water supply, is more convenient, and addresses some potential health risks (albeit, very low likelihood ones).