Urbis talked to Rochelle Payne, who along with her husband Joel, is building a rammed earth house that seeks to achieve ratings in three of the most stringent energy-efficiency certifications.
What is your background? What made you interested in sustainable building?
I am an electrical engineer and my husband is an aircraft engineer. I personally have spent the last 20 years working in construction and about 10 years ago I started working as a sustainability consultant full time, whilst I was living in the Middle East.
We actually started off just targeting The Living Building Challenge as this has not been done in New Zealand before on a residential house and therefore represented a challenge for me professionally. As we were moving through the design process I attended a Homestar conference where a Passive House designer was speaking.
His talk inspired me to look at Passive House and we ended up engaging the speaker (Elrond Burrell from VIA Architecture) to do the Passive House review and design of our house. I personally am accredited as a Homestar Assessor, so targeting 10 Homestar was a given right from the time that we decided to build a new house.
So, briefly, what are the main things your home must achieve?
Our home must be self-sufficient in terms of energy generation, water generation, waste water treatment and storm water discharge. We also cannot use any products or materials from the Living Building Challenge’s Red List (which include PVC) and must divert nearly all of our construction waste from landfill.
To top it off you are doing a large portion of the actual building yourselves. Can you talk us through this decision and the challenges you have faced so far with the build?
We decided to construct the rammed earth walls ourselves. This was actually a recommendation from our architect as he was (and still is) worried about our project budget. Since rammed earth is a highly labour intensive process using relatively low cost materials, he suggested that we could save a lot of money by doing the ramming ourselves. We have never done this before so we are on a massive learning curve. Joel is actually currently in Canada taking a rammed earth course from SIREwall, who specialise in structurally insulated rammed earth walls.
Tell us about your brief to your architects Collingridge and Smith Architects, what were your must haves?
My personal must have is only that we achieve Living Building Challenge certification. Architecturally I’ve always dreamt of having a fabulous, 2-storey entry way, ideally with a chandelier. However that hasn’t turned out to be possible, so I’m making do with a gorgeous staircase and complimentary green wall. Joel’s must haves were a party deck on the roof and a wine cellar. These were eliminated as too costly right at the start, but somehow both have made their way back into the design!
How does rammed earth fit within those sustainability parameters?
Rammed earth is an amazing material. To be honest, I had no idea it even existed until we quite literally stumbled across a rammed earth builder at the Auckland Home Show last year. After seeing and touching the material I fell in love and became a complete convert. We were originally going to build using brick veneer, however the true beauty of rammed earth is that the earth itself is the final finish on both the inside and the outside of the building. There is therefore no need for sanding, plastering or painting, which was one of the biggest attractions to us for using it on the Living House.
We have completed a number of renovations on our previous house and have had extensive experience with the dust and mess that is created when you work with plasterboard. The opportunity to use rammed earth and therefore eliminate the use of plasterboard in our new house was too good to pass up.
The house must be packed with all these practical, functional elements for it to meet certification… did you find that these functional elements often clashed with more aesthetic ones or with things that make a home comfortable?
Actually no, quite the opposite. Thus far every time something has looked like it is going to clash with something else, we have actually ended up coming up with a better overall solution. I think using the 3 rating tools (Living Challenge, Passive House and Homestar) in tandem has actually helped us bring out the best in each rating tool, making the design of the house stronger and more resilient overall.
Have you had to sacrifice anything?
Other than my glorious entry way, the only thing that I wanted that I haven’t been able to have is a gabled roof with roof tiles that have integrated PVs. I really wanted to use that technology on the house and we had actually designed the house like that, however the Living Building Challenge requires you to deal with all of your storm water on site. The gabled roof was generating too much rainwater run off, so I therefore had to change the design to a green roof, which we turned into a flat roof, with a roof garden and deck. Joel got his 3rd storey party deck after all!
What do you think will be some of the most demanding, regular maintenance requirements of this house (I presume there are many that a “normal” house doesn’t have?)
Whilst not demanding, the composting toilet system will require yearly maintenance (and clear out). The evapotranspiration beds and grey water filters will also require regular monitoring and maintenance to ensure that they are operating correctly. The rainwater tanks require a yearly clean and the solar power system will also require supervision and, I would imagine, maintenance as well.
Is building this house a full-time job?
It certainly is. Quite honestly it feels like dealing with Auckland Council on consents is a full time job in itself!
When do you envision it being completed?
The one-bedroom apartment should be finished by Christmas so we can move into it while we build the rest of the house (otherwise we will be homeless). The main house will hopefully be completed by September 2018.
You are documenting this quite thoroughly. Any particular reason?
We want to show other people how to do it. A lot of people won’t attempt these types of projects because they have the perception of it all being too hard. We want to show that it isn’t. And after we have broken the path with Auckland Council others should have an easier path. We are putting up all of our design and documentation on our website for people to freely download and copy so they have an easier path to building sustainable homes. We want and encourage people to emulate and copy us.
Do you have any experience living with the kinds of systems you will have in this house? What do you envision will be the challenges, if any?
Our last house had rainwater tanks and a solar system so we have some small experience with both of those systems. However we have had no experience with composting toilets or on site grey water treatment systems. I would imagine that we will face some challenges with these, including how we will carry the compost out of the basement to the garden every year. It’ll be a challenge to get a wheel barrow up the basement stairs. Buckets perhaps?
What will be the next step once the house is finished?
We move in and have a rest I think. I may end up divorced if I suggest another project straight away! Although I do have a couple of ideas in mind – I’d love to do some social housing using rammed earth, so perhaps that might be on the cards next…
ArchitectureNow is following the progress of the Living House. You can read the first introductory article here.