Ysgol Rhyd Y Llan - New Primary School 

Isle of Anglesey County Council

Project of the Year Winner 2018

Project Name Ysgol Rhyd Y Llan
Project Location Llanfaethlu, Anglesey
Contract Period 56 weeks
Project Start Date 23rd May 2016
Practical Completion 15th August 2017
Contract Value £5.811m
QS/Cost Consultants H.Hyde
Structural Engineer Atkins
Electrical/Mechanical Engineer Atkins/Isle of Anglesey County Council
Principal Designer Isle of Anglesey County Council
Contractor Wynne Construction
Building Control Bowen Consultants
Landscape Architect Wardell Armstrong


As part of Anglesey’s 21st Century Schools modernisation programme, this scheme deals with the construction of a new school to replace the three schools of Ysgol Llanfachraeth, Ysgol Ffrwd Win and Ysgol Cylch Y Garn.

Ysgol Rhyd y Llan is the first full school in the UK to be constructed from straw bale panels. This is a zero waste to land fill system. It shows that the Authority is prepared to engage with sustainable technologies and is committed to deliver highly sustainable community school projects. The completed school building also shows innovation and compassion to the surrounding landscape.

Project Description

The site is located on the outskirts of the village of Llanfaethlu - within an Area of Outstanding Natural Beauty - immediately outside the essential setting of Carreglwyd Grade II* Registered Historic Park. The site faced ecological and archaeological challenges. A cluster of four early Neolithic houses dating back almost 6,000 years, several thousand Neolithic artefacts and two sets of human remains were discovered on the site - experts have referred to the site as one of the most significant archaeological discoveries of the last 50 years and of international significance.

Ysgol Rhyd y Llan is an outstanding Educational and Community facility which has been developed on a site of national historical significance. The school has been designed to compliment it’s natural surroundings and to have minimal impact on the setting of the Listed Church adjacent to the site.

The new school construction utilises a ModCell offsite prefabricated straw bale panel system. This structural panel system is the main wall element of the building. This is a zero waste to land fill system. It’s manufactured using straw and timber elements to form the panel – utilising the thermal insulation qualities of straw bales to form prefabricated panels. It is a carbon positive construction system exploiting photosynthesis to bank carbon into the building fabric. Over the building's lifetime we hope that many students will learn directly from the building itself, positively influencing their understanding of sustainability and how buildings and science can play a direct part in a new low carbon economy.


Sustainability was the main driver for all aspects this project from the very beginning – to include the building design, construction method, landscaping, energy, community benefits and occupation for the building’s lifetime. The project embraced the requirements of BREEAM with the post-construction award on track for an Excellent rating. This was achieved by using renewable technologies, managing the ecological impact, sustainable procurement, waste management and energy efficiency. The low carbon design was adhered to throughout construction to achieve a final EPC rating of A scoring 13 – compared to the required benchmark of 33.

By using the ModCell offsite prefabricated straw bale panel system - the panels can be reused or recycled at the end of the life of the building.This structural panel system is the main wall element of the building and is a zero waste to land fill system-manufactured using straw and timber elements to form the panel - a carbon positive construction system exploiting photosynthesis to bank carbon into the building fabric. It could be said that the school has been ‘grown’. This super insulated system, with a U-value of 0.134, offers air-tightness standards comparable with Passivhaus while also delivering a fully breathable construction, improving health and wellbeing of pupils and educators alike. Whilst also saving money and CO2 emissions year on year.

Low Zero Carbon Technology

A Low or Zero Carbon Technology Feasibility Report was commissioned to set out the low carbon energy strategy for the school - concluding that photovoltaic panels and air source heat pumps were the preferred technologies, together with high insulation values to reduce carbon emissions for the building.

The constructed PV area is 201m² with a projected generation of 27,691 kWh and annual CO2 savings of 14.60 tonnes. An air source pump system of 117 Kw has been installed -providing an annual CO2 savings of 13.80 tonnes.

The As-Built air leakage rates for the building achieved 4.52 (m³/hr/m²) at 50Pa against the target of 10.0 (m³/hr/m²) at 50Pa as required by the regulations.

The design stage Building CO2 Emission Rate achieved 2.2 kgCO2/m²/annum against a target rate of 15.1 kgCO2/m²/annum. The constructed rate is 3.3 kgCO2/m²/annum against the target rate of 15.1.


Energy usage for the first few months of occupation have been monitored and compared against the energy usage within the three schools which have been replaced. Based on current energy usage data and Renewable Incentive Scheme contributions, the new school is operating at an energy cost saving of 29% against the three previous schools.

Community Benefits

Local employment featured strongly on this project, despite being located in a rural area.  The project safeguarded 298 construction jobs, with 41% living within 30 miles of the site and within Anglesey and an additional 28% living within the North Wales region, totaling 69% living in Wales. On this project 71% of the project spend remained within North Wales to local SMEs with 36% of this for Anglesey-based companies.

Waste & Emission Reduction

Waste and emission reduction was also a key driver for the project and the school visibly demonstrates low energy design, construction methods and materials. Bu using the ModCell panels, waste in construction was reduced through the manufacturing process: wood waste was used in the factory’s biomass boiler; waste straw is composted, used as bedding for farm animals or recovered as biomass. The ModCell panel formed 748m2 of the elevation of the building. The straw and FSC timber used to form the ModCell panels sequesters over 145kg per m2 of elevation. As a result the total amount of CO2 sequestered into the ModCell element of the building was over 108,460 kg of CO2.

A cut and fill exercise was carried out to retain almost all of the 200+ tonnes of excavated material by re-modelling the site topography and re-distributing the soil to create plateaus and landscaped areas. Local stone was used for finishes, brought from Penrhyn Slate quarry in Bethesda, based 30 miles from site.

In total 93.5% of eligible materials were recycled and 93.11% of waste was diverted from landfill as a result of the scheme.

Lessons Learned

The lessons learned from this project are vast. It was the first scheme which the in-house architectural team delivered using the principles of BIM Level 2. Working in partnership with Wynne Construction was key to achieving this. It has been a successful learning experience. The use of the straw bale panels has been a new modern construction system for the whole design and construction team to learn and understand. It has had a very positive impact and interest from within the local agricultural community. 

This project has also been a success due to collaborative working. From early stakeholder engagement, community engagement and engagement with the school pupils and staff. Collaboration on site has also been of huge importance – particularly between the archaeology team, ecology team, design team and main contractor.