All posts by Richard Dormandy

Conventional BUild Carbon Footprint: 400 tonnes. OUR BUild: MINUS 479 tonnes.

An average 85m2 UK home of brick and concrete is said to release 68 tonnes CO2 in construction. For a building like ours of 643m2, we would expect to release something like 450 tonnes with conventional construction.

Using Alternative Construction the picture is more like this (from the ground up):

Crushed Concrete MOT Type-1:  Waste product, minimal embodied energy of crushing and delivery. Plant is under 10 miles from site.

Scrap Tyres.  Waste product past end of life – virtually no embodied energy. Since they are now repurposed, they are also saved from landfill.

Pea Shingle – (packed into tyres) refined and washed in Kent, 2 hour’s drive of site.

Concrete deemed necessary : less than 0.5 tonnes embodied CO2.

Timber Frame, sustainably forested, including windows and ground floor:  Approximately 85 tonnes SEQUESETRED CO2 – more than offsetting milling and transport costs.

Straw Walls:  waste product, past end of life. 3-hour drive to London. Approximately 35 tonnes SEQUESTERED CO2

Lime:  gives off CO2 in manufacture (like cement) but, unlike cement, reabsorbs it as it cures, forming Calcium Carbonate. Generally considered carbon neutral apart from transportation – 3 hrs drive

Clay:  carbon neutral.  Dug and processed on site.  Secondary layers processed in Germany – embodied energy: mainly transportation.

Windows:  triple glazed, manufactured in UK and Poland. 7 tonnes embodied C02, (compare 8.2 tonnes PVC-u) Carbon savings in use will recoup the embodied energy within 20 years.

Roof Covering: 99% Recycled waste product – IkoSlates. Total embodied energy has been independently calculated at less than any alternative.

Solar panels:  embodied energy recouped in less than 2 years – thereafter carbon negative.

Energy:  all electric supplied mainly by solar PV and ASHP.

Air-Tightness will achieve a score of 2.5 or lower.

Energy Profile in Construction: minimal use of plant such as excavators; zero use of cranes. Majority of construction processes manual.

Energy Profile In Use – minimal due to excellent thermal insulation.

Lifespan: up to 200 years

CONCLUSION: The sequestered (ie captured) CO2 in timber and straw) more than offset the embodied carbon in other materials, bringing the whole construction process to a Carbon Negative figure of around 90 tonnes. This compares to a Carbon Positive Footprint of around 400 tonnes had we used conventional construction materials and processes.

Thanks to minimal energy emissions in use, our building is still likely to be Carbon Negative at the end of its useful life. Compare this to the hall built with conventional means 450 tonnes / 200 years – a minimum of 2.25 tonnes per year, plus C02 released in use.

Add to this 331 tonnes CO2 avoided through use of Solar PV over 60 years, plus 28 tonnes through avoidance of concrete. the total negative carbon footprint of our building is -479 tonnes.

Shortlisted for the M&S Energy Community Energy Fund!

M&SWe’ve just heard that we’ve been shortlisted to receive £12,000 from the M&S Community Energy Fund – and it could be more if our project is chosen to be one of their flagships.

We are still to receive details on the next stage of the project, but in brief, we will be invited to set up a web page on the Energy Fund website from the beginning of August; then, from September 1st we’ll need to get as much support for it as possible.

So let’s not forget the lessons learnt in recent days:  every vote really does count!

More details to follow.

We have raised a whopping…

funding-05£348,000 so far!  Our initial fundraising aim was £380,000 so that is an incredible achievement – 92% of the target raised! Many thanks to all our supporters.

Unfortunately, costs have also risen.  A while back, we revised our fundraising aim to £460,000, which puts us back down to 75% achievement, but in fact the target will probably have to increase further.

We are currently working on firming up all the costs in more detail.  Some aspects have worked out to be less than our initial estimates.  The main things that look to be a lot more expensive are:

  • Our two main staircases will have to be custom built for around 65k – about £40k more than anticipated;
  • our ventilation system will cost about £45k – about 30k more than anticipated;
  • and our foundations will cost £60-90k which is about £30-60k more than anticipated.

These changes are partly due to the initial unknowns of a pioneering building, and partly because the building has developed beyond our initial sketches in order to be fit for purpose.

 

Bird’s Eye View

Aerial Visulaisation EastAerial Visulaisation West

 

 

 

 

 

 

Kuba has just sent me these two stunning visualisations of the new building.  The first, viewed from the South-East, shows the solar panels along the south roof, and the wonderful entrance staircase.  The second, viewed from the North-West, shows the link to the church, with the kitchen nearest.  Meanwhile Sally Redway is working on some 3D animations of the inside which we shall post when they are ready.