Low Impact Timber Frame Construction

Here are some the articles and links we found fascinating this last week.

Peatlands are vital carbon sinks, and at risk from draining agriculture

https://www.farmweekly.com.au/story/7309130/peatlands-critical-against-climate-change/

The leaked IPCC Report is really nor mincing its words or watering down its message. We must act now.

https://www.theguardian.com/environment/2021/jun/23/climate-change-dangerous-thresholds-un-report

Quite right- is should always be viable to create affordable housing- Nil affordable Housing ruled unjustified.

https://www.planningresource.co.uk/article/1720557/nil-affordable-housing-ruled-unjustified

An amazing Timber University in Oregon

https://www.dezeen.com/2021/06/23/mga-mass-timber-buildings-forestry-college-oregon/

These eco homes in Bristol are really amazing- right on the money- more of this please!

https://www.business-live.co.uk/economic-development/eco-homes-proposed-bristol-garage-20871827

Not affordable- but an amazing building none the less, yours for less than 2 million!

https://www.mansionglobal.com/articles/an-eco-friendly-home-floating-on-londons-river-thames-asks-1-75-million-228321

Some stunning ‘igloo’ style tiny homes in Vancouver- replete with indoor gardens for micro-greens and food production 

Tiny home setups that are sustainable alternatives for designing eco-friendly modern architecture!

All things forestry, housing, and climate related. If you’d like to share some news with us please feel free to email chris@typren.co.uk

In many areas of Wales affordable housing is a real issue. Second and holiday home purchases, and difficulty in obtaining planning permission keep many locals off the housing ladder- often forcing them to leave the area completely 🙁

Interestingly in Yorkshire affordable homes have just been given the go ahead on the basis of need. Maybe something for Welsh planning authorities to consider in the future?

https://www.planningresource.co.uk/article/1718794/affordable-housing-exception-site-justified-housing-need (PAYWALLED)

Housing stock in Wales is also very thermally inefficient, especially in industrial and post industrial areas dominated by terrace housing. In fact, Wales has some of the oldest housing stock in Europe.

Good to see what is happening in Glasgow, with funds for retrofitting

https://www.scottishhousingnews.com/article/wellhouse-housing-association-invests-80-000-into-future-proofing-homes

In the Orkney local needs are being met with energy efficient housing:

https://www.scottishconstructionnow.com/article/housing-association-announces-significant-new-projects-in-orkney

While we are all for innovation it would be good to know what readers of our blog make of forest carbon credits!? Will this encourage more carbon capture, or just allow polluters to greenwash?

https://www.investmentweek.co.uk/news/4032457/gresham-house-forestry-fund-pay-investors-carbon-credits (Complimentary 12 month access on signing up)

A nice idea for re-wilding and natural tree growth in England- but the devil will be in the detail!

https://www.theguardian.com/environment/2021/jun/09/forestry-commission-reveals-plan-to-create-new-english-woodlands

Should eco-homes have work from home office space included as standard? We need to commute less, so is this a good move?

https://www.fenlandcitizen.co.uk/news/new-eco-homes-being-built-in-march-will-include-offices-9202757/

Tiny Homes for the Homeless? Getting homeless people a home is vital, but any Tiny Homes should be high quality.

https://www.wfxg.com/story/44065286/aiken-organization-seeks-city-help-with-tiny-homes-project-for-the-homeless

There is a good chance that you have heard of Larch Disease. Larch is a common and abundant resource in Wales, and the trees are currently under attack from an invasive disease to which they have little immunity. It is in fact a bit like Dutch Elm disease, or Ash Dieback. These tree diseases have seen elms practically eradicated from the UK, and the numbers of Ash plummet. If you live in a rural area of Wales there is a good chance that you have already encountered larch being felled in great numbers.

In this post we’ll explore what Larch disease is, what current Welsh government policy is to manage it, and how this affects Tŷ Pren and other timber builders in Wales. We’ll also explain what changes we’d like to see to the policy, and how you can help us utilise this valuable resource for low impact and zero carbon construction.

What is Larch Disease?

In Latin the disease is called. Phytophthora Ramorum.  It is an oomycete, which is a type of algae in the Protist family, a single cell organism similar to green algae. It is a plant pathogen that has spread globally. It does not just affect Larch, but other species. It has been responsible for the decimation of the Oak populations of Oregon and California. The disease in Oak is known as Sudden Oak Death. The symptoms of disease in an affected tree include distinctive cankerous sores that bleed, and dieback of the leaves and foliage.  An infected tree often dies.

It also infects plants such as the Rhododendron, and infectious spores grow inside them which exacerbates the spread of the disease which can then be transmitted in rainsplash and rainwater.

There are no known treatments for the disease, so once an infection is spotted the tree is felled, and disposed of, as are the trees nearby, which may not even be infected.

How Are The Welsh Government Managing Larch Disease?

The issue with Phytophthora Ramorum is that it does not just attack one species. Oak has been affected, as has Douglas Fir, and Sweet Chestnut. This spells bad news for the larch. Until recently just one case of confirmed Phyophthora in larch resulted in felling orders- and every larch in the vicinity of an infected tree, 100m square, would need to be disposed of. To prevent the spread of the disease, and further interspecies infection, the Welsh Government and Natural Resources Wales plan to fell ALL larch by 2030. This larch is then sold to the highest bidder, usually for chipping and biomass incineration.  Infected Larch can still be used, however, for roundwood timber frame construction, as Phytophthora does not live in the wood used when building with roundwood, but the bark and brash.

What Does This Mean For Tŷ Pren and the Welsh Timber Frame Building Industry?

In short, it is not good news. Not good news at all. Tŷ Pren build extensively with larch as it is cheap, durable, strong, and thermally efficient, fast growing, and abundant. We fell only the trees we need, managing the woodlands, and replanting areas with broadleaf when appropriate. While other types of timber can be used they are not as readily available, or fast growing as Larch. In short- in the next few years as it stands, Tŷ Pren will be forced out of business. Unless we can change the policy to fell all larch, or secure 100s of tonnes of larch to tide us over while replacement trees grow for 20 years plus. Sadly at present we do not have the storage for Larch in that quantity, and we lack the lobbying profile to change government policy in such a short time frame.

This is tragic, not just because it affects our livelihoods, but because we have developed a zero carbon zero waste affordable means of house building, that is capable of being scaled up to meet the housing needs of Welsh communities the length and breadth of the nation, creating jobs, skills, and wealth. To see this potentially blighted causes us considerable concern and sadness.

How Can You Help ?

If you are a business, individual, or organisation affected by the Welsh clear felling Larch policy please get in touch. If we can work and communicate together our voices will be louder and more clearer. We can explore lobbying for policy change or adaptation together.

We are also looking for premises to store larch, in a dry area, for future use. If you know of anywhere that might be suitable please get in touch.

If you are a policy maker, or civil servant, sympathetic to our dilemma please do get in touch if you can offer advice or assistance.

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Carbon Capture And Roundwood Timber Frame Construction

At Tŷ Pren we are passionate, and I mean really passionate about roundwood timber frame buildings. This is not just because these buildings are beautiful to live in and visit, because of all the natural materials used in the construction, but because the homes we build are Zero Carbon, and in most instances carbon negative. While most of the rest of the construction industry is using petrochemical technologies, and working out how to Reduce their carbon footprint- we are looking to build more homes that Capture carbon. Pretty cool.

So How Do We Do Capture Carbon?

This is not rocket surgery or brain science. It is dead simple in fact. We all know from school that trees use photosynthesis to grow. And they suck up carbon dioxide from the air, release oxygen, and store carbon. When  trees are felled or fall they decompose, this carbon is released back into the atmosphere. When a tree is burnt that process  of release is accelerated. When the wood is used to make something, buried deep (as happens when fossil fuels are created) , or drowned in water, that carbon is stored and captured. Any waste wood rots and releases the carbon.

Roundwood Carbon Benefits

This is the clever thing about roundwood timber frame- or Building with Poles. There is practically no waste, and no sawmills creating excess wood waste. The off cuts are used elsewhere in the build. So while it takes craft and skill to successfully build using roundwood- the carbon benefits are quite impressive.

The Maths and Science Bit:

Before going into the specifics- we do want to qualify- at the Tŷ Pren cooperative we are builders, not scientists specialised in carbon lifecycle, and product, analysis. So any corrections, additions, or expansions on all this are really welcome. That said we are competent and have done our research best we can, thanks to Mr Google among others.  

It is possible to estimate (to a mostly reliable order of magnitude) any  tree’ s CO2 sequestration like this: (thanks to ecomatcher.com for this)

“Step 1: Determine the total green weight of the tree

The green weight is the weight of the tree when it is alive. First, you have to calculate the green weight of the above-ground weight as follows[2]:

Wabove-ground= 0.25 D2 H (for trees with D<11)

Wabove-ground= 0.15 D2 H (for trees with D>11)

Wabove-ground= Above-ground weight in pounds

D = Diameter of the trunk in inches

H = Height of the tree in feet

The root system weight is about 20% of the above-ground weight. Therefore, to determine the total green weight of the tree, multiply the above-ground weight by 1.2:

Wtotal green weight = 1.2* Wabove-ground

Step 2: Determine the dry weight of the tree

The average tree is 72.5% dry matter and 27.5% moisture[3]. Therefore, to determine the dry weight of the tree, multiply the total green weight of the tree by 72.5%.

Wdry weight = 0.725 * Wtotal green weight

Step 3: Determine the weight of carbon in the tree

The average carbon content is generally 50% of the tree’s dry weight total volume[1]. Therefore, in determining the weight of carbon in the tree, multiply the dry weight of the tree by 50%.

Wcarbon = 0.5 * Wdry weight

Step 4: Determine the weight of carbon dioxide sequestered in the tree

CO2 has one molecule of Carbon and 2 molecules of Oxygen. The atomic weight of Carbon is 12 (u) and the atomic weight of Oxygen is 16 (u). The weight of CO2 in trees is determined by the ratio of CO2 to C is 44/12 = 3.67. Therefore, to determine the weight of carbon dioxide sequestered in the tree, multiply the weight of carbon in the tree by 3.67[1].

Wcarbon-dioxide = 3.67 * Wcarbon

Example of CO2 calculation

Tree details:

10 years old tree

5 meter tall or 16.4 feet tall 

25 cm trunk or 9.8 inch trunk 

Wabove-ground= 0.25 D2 H= 0.25(9.82)(16.4) = 394 lbs

Wtotal green weight = 1.2* Wabove-ground= 1.2 * 394 = 473 lbs

Wdry weight = 0.725 * Wtotal green weight= 0.725 * 473 = 343 lbs

Wcarbon = 0.5 * Wdry weight = 0.5 * 343 = 171.5 lbs

Wcarbon-dioxide = 3.67 * Wcarbon  = 3.67 * 171.5 = 629 lbs CO2 sequestered in 10 years; that equals 285 kg. EcoMatcher uses an average of 250 kg CO2 sequestered per tree. “

Ty Pren mostly build using European Larch. An average three bedroom house made from a roundwood larch frame, would use 9 entire larch trees- more if you consider roof and flooring- but to take waste into consideration 9 is a safe assumption, so we estimate:

Average Dry Weight (DW) a  mature European Larch= 575KG https://www.wood-database.com/european-larch/

Average Carbon weight (CW)- CW= DW / 0.5

Weigh carbon-dioxide = 3.67 * CW  = 3.67 * 575KG = 1.725 Tonnes of carbon captured per tree.

1.725 x 9 = 15.525 tonnes of carbon captured per average 3 bedroom build.

Lifecycle Carbon Savings?

This is of course not the whole picture- as other natural materials like straw bail and hempcrete also capture carbon. And an off grid renewable home will also produce less c02 emissions- The average family produces 3.2 tonnes per annum heating and powering their homes.

So we estimate- and this is the starting point for more rigorous research and debate- that a home built using natural materials and powered exclusively by renewables, produces 64.48 tonnes carbon less over its lifecycle than a conventionally built and powered home. With 15.525 tonnes or carbon capture. 

Potential At Scale

The figures for one property are an impressive estimate.   If 2000 new homes annually were built using these technologies you get into game changing territory. We are not able (yet if ever) to produce 2000 homes a year- but we are interested in creating an industry that can, and being part of that.

Needless to say the principle of capturing carbon in a build, rather than creating carbon in a build, is solid, and warrants more attention, in our opinion anyway.

If you’ve comments and want further discussion on this please do get in touch.