Architype
Holy Trinity Primary School
London Borough of Richmond upon Thames
Brief
Architype was appointed to expand the existing 1970s primary school from 1 to 2 form entry, to meet rising demand for school places in the area, whilst keeping the friendly, nurturing atmosphere of the school, along with refurbishing the existing buildings.
Rationale
A key aspect of Holy Trinity School is its ethos of shared teaching and the welcoming feel of the school environment. To meet this, our design integrates a series of super eco cross-laminated timber wings with green roofs that connect lightly to the existing structure to maximize future flexibility, and create a signature visual form for the new school. These ‘green wings’ enhance the free flowing character of the school, providing direct connections to the outside, and a series of delightful courtyard spaces run between. Our environmental ethos runs throughout, and natural, expressive materials are crucial to give the school a warm, rich, tactile environment, that feels natural to the touch and is a great backdrop to the children’s activities and artwork. Circulation has been rationalised and improved, and the hall is now the central ‘heart’ of the school around which a lively circulation space branches off into learning and social spaces.
- Timeframe
- On Site / Mar. ‘10
- Completion / Apr. ’11
- Gross Internal Floor Area
- 1,185 sqm
- Construction Type
- Cross-Laminated Timber Construction
- Costs
- Total / £4,700,000
Consultation
From the start, the school requested “that the children get involved as much as possible, and Architype really responded to this, consulting with them in a variety of ways to find out what they wanted, and what they wanted to improve. It was imperative to hear the child’s voice in the design of their learning environment.” Penny Cox, Headteacher.
Architype’s consultation process included presentations of the proposed design at morning assemblies, and activity workshops involving children from all years. A balloon activity encouraged children to mark areas of the school they liked and disliked with coloured balloons and then explain their choice on tags. Lively modeling activities allowed children to express what changes they would like to see in specific sections of the school. The children’s insights proved invaluable to the design process. Spending time in the school was especially useful for the Architype team as we gained a deep understanding of its ethos and the day-to-day school environment.
We also ran a community consultation day using presentation boards to communicate key design ideas in the form of schematic diagrams, 3D visualisations, proposed plans and a physical model. Invitations to drop in were sent to local residents, the neighbouring church, parents and allotment holders. A range of useful comments were collated and feedback forms were completed by most visitors which fed into the design of the overall building.
Process
The construction system for the new buildings is a Cross Laminated Timber modular system, which was fabricated off-site and then transported to be rapidly built on-site onto foundation sub-structures. The school was in occupation throughout the whole process, and we developed a carefully phased solution that removed the need for temporary accommodation and reduced disruption.
Results
The school has increased its capacity from 210 to 420 pupils. The new buildings provide 11 classrooms, 2 shared resource areas, a new staff room block, and additional circulation space. A new inviting entrance leads through to a suite of classrooms and group spaces that open out into the landscape. The new wings are highly energy efficient and very comfortable.
The cross-laminated timber (CLT) has very low embodied carbon, and creates a lovely warm textured interior. The new wings are airtight with high performance triple glazed windows and mechanical heat recovery. An earth tube system cools the classrooms in summer and pre-heats incoming air in winter. We specified renewable bio-based products and finishes to minimise embodied carbon and toxicity, and ‘Self-finishing’ components to reduce long term maintenance. A green roof system helps to acoustically insulate the building from high levels of aircraft noise. Architype also refurbished the existing building, including converting an existing classroom into a library and ICT hub with SEN space, and extending the kitchen.
Environmental Strategy
The new buildings are designed using the principles of Passivhaus design; the buildings are externally insulated, adopt a lightweight cross-laminated timber construction with low embodied carbon; achieve an excellent air tightness, and adopt a full Mechanical Ventilation Heat Recovery (MVHR) system.
Building Performance
An average daylight factor of 4% was targeted and achieved throughout the new classroom and shared areas to reduce the need for artificial lighting. All new lighting to classrooms and shared areas was specified with daylight dimming, occupancy sensing and overriding user controls.
The new wings are designed to a very high energy standard, to enable both the new build and the refurbishment to achieve BREEAM Excellent. The existing school has been refurbished with low energy lighting and new heating systems. The Chair of Governors has stated that the school’s energy bills have actually gone down since the building was fully completed, even though our extension essentially doubles the size of the existing school.
The form and orientation of the new buildings was carefully modelled and analysed to maximise daylight and thermal gains during the winter months while avoiding overheating during the summer. The school is located under the Heathrow flight path and so acoustics were of utmost importance – our air tight, triple glazed solution with MVHR avoids reliance on opening windows for summer cooling. Open cell insulation combines with the mass of the green roofs to act as an acoustic absorber protecting against high levels of aircraft noise. An earth tube system provides pre-cooling of incoming air in summer and preheating in winter, and Ground Source Heat Pumps are installed. Extensive green roofs increase biodiversity and reduce water run off. Photovoltaic panels are installed on the school’s existing roof.
Our aim was to use and express a range of natural materials; reduce plastics and composites in construction; and incorporate as many pre-fabricated elements as possible, including surface mounted pin boards, and distinct furniture packages. Low maintenance costs are achieved through the wide use of robust, ‘self finished’ materials including the CLT. Deep overhangs around the building ensure that walls and the expressive timber soffits are protected – this also has a big impact on maintenance costs. In circulation areas, paints are chosen for their high durability specification.
The school used to entirely replace sheet carpets on a regular basis — our specification of carpet tiles significantly reduces wastage and cost for the school. Architype worked with Bioregional on a WRAP Waste Minimisation programme as part of the design development.
The buildings have been constructed with light connections between the old and new elements, which provides flexibility to enable the older parts of the school to be easily replaced to suit the changing needs of the school over time. Raised access floors provide service zones that allow for the flexible upgrading or routing of services in the future.
Architype designed the scheme in detail to RIBA stage F. The project was then tendered as a Design and Build contract. Architype was then retained by the client as checking architect – ensuring that the school was delivered to the original vision and design. Construction took 60 weeks and the school was in occupation throughout.
Architype Team
- Bob Hayes
- Christian Dimbleby
- Gareth Selby
- James Todd
Project Partners
- Main Contractor
- Apollo Group
- Structural Engineer
- Techniker Ltd
- Services Engineer
- CBG Consultants stage A-F
Elementa Consulting stage F-L - Landscape Architect
- Livingston Eyre Associates
- Quantity Surveyor
- Synergy LLP