Woodknowledge Wales

Woodknowledge Wales

Inspiring innovation through collaboration

Home Grown Homes

Clwyd Alyn housing project surpasses RIBA 2030 Climate Challenge target

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A timber based Clwyd Alyn social housing project in Llanbedr near Ruthin constructed by Williams Homes surpasses the embodied carbon target set down by RIBA in their 2030 Climate Challenge campaign.
An embodied carbon analysis undertaken by Eilidh Forster of Woodknowledge Wales to a measurement methodology agreed by RIBA and RICS returned a value of 253 kgCO2/m2 which is a 16% improvement on the RIBA 2030 target. See below (graph)

This project really does represent an effective response to the climate emergency and demonstrates that Welsh Government should implement an embodied carbon policy so that all homes in Wales are required to be low carbon. This is one of the policy recommendations in our Zero Carbon Homes report launched at WoodBUIILD 2019.

Clwyd Alyn social housing project in Llanbedr near Ruthin constructed by Williams Homes

The 36-unit housing Innovative Housing Programme supported scheme in Llanbedr near Ruthin is one of the exemplars for the Home-Grown Homes Project and provides compelling evidence for timber construction using Welsh trees. Welsh grown spruce supplied by Pontrilas Sawmills was used for the structural frame and larch grown and processed near the site was used for the external cladding. All joinery elements were wood based, and wood fibre insulation was used as an alternative to petrochemical foams.
Now that the Llanbedr project has beaten the RIBA 2030 target for embodied carbon, the Home-Grown Homes team are turning their attention to measuring the operational carbon emissions – the emissions associated with the buildings use. The design energy performance suggests a level that approximates to the RIBA target for 2025 – 70kWh/m2/y. See below (chart).

RIBA 2030 Climate Challenge target metrics for domestic buildings


However, RIBA demands that the operational energy performance is determined through post occupancy evaluation rather than using design energy performance. Over the next 6 months, Cardiff Metropolitan University with the support of Build Test UK aim to conduct an energy performance evaluation using established and novel techniques. This evaluation will determine if the building can be expected to perform at or near its design energy performance to provide a truly low carbon and sustainable home both in construction and use.

From garden sleeper to beautiful window. Challenging perceptions about Welsh timber

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Custom Precision Joinery rose to the challenge laid down by Dainis Dauksta at a Woodknowledge Wales knowledge event on Developing the Welsh Joinery Sector – Barriers and Opportunities for Windows by offering to make a demonstration window from (1) local Welsh timber (2) to a specification acceptable to housing associations and (3) have it ready for WoodBUILD 2019. We were not disappointed!
This second knowledge event in our “Campaign for Wood Windows” looked at how the Welsh Joinery sector can respond to the real and growing demand from the social housing sector to supply wood windows and ultimately how the joinery sector can access home-grown timber to be used in making those windows.

Larch on planer showing straightness of the grain

Larch for the windows on planner. This photo shows the straightness of the grain after the first 20-30cm which can be removed.

During the event Dainis Dauksta (sawmiller, designer and consultant) had challenged perceptions that Welsh (and UK) forest plantations provide low grade softwood which is only fit for fence posts and biofuel. He urged us all to learn more and not to make the mistaken judgement that fast grown is always inferior to slow grown or that large ring width means low density. His talk illustrated how large Welsh logs which are currently being used in low value markets such as fencing and bio-fuel can provide high grade joinery timber.

The Timber

Two reject larch garden sleepers (2.4m*250mm*125mm) obtained from BSW were resawn (by Dainis Dauksta) into joinery sizes as specified by Custom Precision Joinery. The sleepers, which had been air dried were cut so that the juvenile corewood [1] was specifically sawn out and excluded from the final joinery grade product, this is because the core wood can have properties which are significantly different, and variable compared to the mature wood.

“Home grown larch is currently such an under-utilised joinery timber” said Dainis Dauksta who supplied the material used by Custom Precision Joinery. “High quality joinery grade timber is currently going into low value end markets which is such a waste of our resources.  This project showed just how easy it was to select and cut joinery grade timber from larch that was being sold as reject garden sleepers.”

Custom Precision Joinery checked the joinery grade larch on delivery and confirmed that it was fit for purpose. The scantlings where then conditioned in their workshop for two weeks before machining into the required profiles.

British grown larch is a moderately durable softwood with a colour that ranges from a light to dark brown heartwood to a white sapwood. It has a density of around 550kg/m3 at a moisture content of 12%.  When wet it has a tendency to distort but once dry it is generally stable.  Potentially large volumes of larch could become available in Wales because of the Phytophthora ramorum epidemic.  Larch is a very useful construction timber and larch grown in Wales can already be visually strength graded to C24.  It can be used for cladding, structural and joinery applications. High-quality stainless-steel fixings should be used to avoid corrosion of fixings.

The Windows

2 windows displayed on a table at a conference trade show

Two windows made by Custom Precision Joinery from Welsh larch and on display at WoodBUILD 2019.

Two windows were made at Custom Precision Joinery in Buckley, north Wales, they were the same design but had different paint finishes.  The windows were made to a design supplied by Coastal Specialist Ironmongery Ltd (also participants in our windows workshop). The design used was one which has already been approved as suitable for social housing.

“We are very pleased with how these windows turned out” said Colin Morris from Custom Precision Joinery. ”A large percentage of home grown timbers are generally of a higher standard than that of imported timbers. However, the Welsh supply chain is an issue for manufacturers in the joinery sector like us. But with the right investment and perseverance Wales has a unique opportunity to enhance this sector.”

What next?

Profile detail of window made by Custom Precision Joinery, fixtures by Coastal Specialist Ironmongery and paint finish by Remmers (UK) Lrd.

This project has shown that high quality joinery items can be made from Welsh timber that is currently being sawn and sold for low value garden sleepers. Just by grading and sawing that same material in a different way it has been transformed into a high value joinery grade timber.
Simple interventions like this could help develop the supply chain for Welsh timber and offer smaller sawmills opportunities to diversify and provide higher value products into the joinery sector. However, the demand for joinery products made from Welsh timbers need to developed. One way to do this is by working with housing associations and local authorities. This is being done through the Home-Grown Homes Project, led by Powys County Council which is exploring supply chain interventions to encourage growth of the timber sector in Wales.
At the end of the Home-Grown Homes Project a set of recommendations will be presented to Welsh Government with case studies to demonstrate how interventions could help improve the supply of Welsh timber to Welsh house building manufactures to build more and better homes.

Woodknowledge Wales would like to thank Custom Precision Joinery for offering to make these windows from Welsh timber and putting them on show at WoodBUILD 2019. We would also like to thank Coastal Specialist Ironmongery for their part in providing the specification for the window design and Craig Lovatt, formally of Custom Precision Joinery and now of Remmers (UK) Ltd for initiating the project.

[1] Corewood or ‘juvenile wood’ is found within the first 10–20 annual rings adjacent to the pith.

Timber Cladding Videos from RIBA

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These three RIBA videos by Swedish Wood aim to help you understand and learn about the following topics:
– Understand how to design using timber as an external cladding and the design effects that can be achieved
– Understand how to ensure the sustainability of timber cladding and the procurement of legal and sustainable timber
– Understand how to specify and detail cladding
– Understand how to issue fixing instructions to the contractor
– Understand how to issue coating and maintenance advice to the contractor and customer
– Learn about the relevant British Standards and Building Regulations relating to timber cladding

Timber Cladding: How Timber Cladding Can Meet your Project and Quality Objectives: RIBA Plan of Work Stage 1 (07:18) by Swedish Wood

Timber Cladding: Concept Design: RIBA Plan of Work Stage 2 (15:46) by Swedish Wood

Timber Cladding: Technical Design: RIBA Plan of Work Stage 4 (10:15) by Swedish Wood

 

Welsh Timber Frame Capacity Report. March 2019.

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This report was commissioned to update the research carried out during the summer of 2017, to revisit the impact of Timber Frame house building in Wales. This paper is prepared to highlight to the Welsh Assembly and the Housing Market in particular that the Timber Frame sector is strong and active throughout Wales. The report notes however that for off-site manufactured product to be truly successful, a number of changes are necessary, not least of which is an acceptance by clients that investment in manufacturing capacity requires far greater transparency of forward demand and commitment to the supply side that it will be committed to and delivered.
Read the report here.

Prosperity for all: A low Carbon Wales

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Prosperity for All: A Low Carbon Wales. Was published by Welsh Government on 21 March 2019. It sets out how WG will meet their first carbon budget (2016-2020). The Plan sets out 100 policies and proposals, broken down by all portfolios, which demonstrate the collective Cabinet commitment to accelerate the transition to a low carbon economy in the years ahead.
The Plan outlines the Welsh Government’s approach to cut emissions and transition to a low carbon economy in a way which maximises wider benefits for Wales, ensuring a fairer, healthier and more equal society. Lesley Griffiths, Minister for Environment, Energy and Rural  Affairs made clear at the launch that, “this can only be achieved by collective action across Government, business and society.”
The Plan pulls together 76 existing pieces of policy from across the Welsh Government, UK Government and the EU where decarbonisation is integrated either as a direct outcome or a wider benefit. Some of these are new Welsh Government policies which have come on stream since the start of the budget period, such as the Economic Action Plan and Renewable Energy Targets, or revamped policies such as Planning Policy Wales where decarbonisation is now a central pillar.
Read the Plan here

ASBP – The Multiple Roles of Insulation

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This Alliance for Sustainable Building Products (ASBP) briefing was published on the ASBP website in 2018 as is part of a planned series of ASBP
industry briefing papers aimed at generating a greater understanding of the roles and capabilities of natural fibre insulation (NFI). The aim of these briefing papers was to enable industry to deliver better buildings designed to take advantage of the significant building performance benefits of NFIs.
Read the full report here.

Grŵp Cynefin video about benefits of building with timber

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Video from Grŵp Cynefin explaining the benefits of choosing to build with timber. In this video see the project under way at the former Buckley Medical Centre, in the town centre. The £2.2m two-storey timber-framed building will comprise 14 two- and ten one-bedroom apartments and is being developed in partnership with Flintshire County Council.