Low Energy Learning
The UK's first Passivhaus secondary school – the £40million state-of-the-art Harris Academy in Sutton – has opened its doors and sets a precedent for low carbon, high performance buildings.
Delivered for Sutton Council, and accommodating up to 1,275 students aged 11 to 19, the new building is the UK's largest Passivhaus school and is run by the Harris Federation.
The building is an impressive focal point for the wider site's ambitious masterplan as the new London Cancer Hub (LCH), a world-class research and treatment facility. A collaboration between The Institute of Cancer Research and Sutton Council, the LCH is a pioneering future research park, dedicated to research to cure and treat patients with cancer. As the first scheme to complete on the site, the Harris Academy Sutton will have a special focus on the science disciplines, with the objective of inspiring the scientists of the future. The facility will build links with local employment partners to enhance student experience and facilitate the transition to further education with university style learning.
Architype have worked closely with educationalists throughout the design process to the facility to tailor the students' needs. Classrooms and teaching accommodation span four storeys, including eleven labs, to suit the STEM school's science-focused aspirations. A flexible demonstration lab will accommodate up to 60 guests to encourage students to take part in extra-curricular research and national events such as British Science Week.
Classrooms are light and inspiring with optimised spatial orientation, the result of extensive daylight, noise, transport and ecology surveys conducted by Architype. Cross-laminated timber (CLT) roofs incorporate the natural harmony of the building, with non-toxic materials providing exemplary air quality to provide an optimised massing. This dynamic layout maximises the site's usable external areas with terraced seating and social courtyards, further adding to the knowledge sharing and 'university campus' feel of the scheme.
"As a cornerstone to the new science development," says Ben Humphries, Architype's design team project director. "The design needed to create inspirational spaces for learning, demonstrate exemplar performance and environmental credentials and respond sensitively to its suburban setting. From the building's CLT frame through to the timber cladding, we carefully selected robust, natural and non-toxic materials which provide excellent health and wellbeing benefits and are complemented by the beautiful copper facade.
"Despite the large scale of the Passivhaus building, it sits comfortably within the site, nestled among neighbouring homes while making a quiet statement about its intention to inspire scientists of the future. The high quality of the design and construction are a tribute to the whole team's collaborative approach, and evidenced by the feedback from students and staff, who have reported that everyone remains alert even at the end of a long school day."
Copper has been particularly utilised as a visual marker for the areas of the building which also serve the community. The stunning 715sq m sports hall for instance, clad almost entirely with copper and internally finished with exposed timber, is to be used by students as well as local residents after hours, contributing to the future health benefits which incorporate the core values of the wider site.
Architype provided lead consultancy, architectural and principal designer services for the pioneering project. It will be the first Passivhaus secondary school in Britain and the second largest Passivhaus educational facility with a 10,625m2 gross internal floor area. Passivhaus is often described as 'the gold standard' of low-energy building, taking a fabric-first approach to ensure optimum internal conditions. Architype's work in Passivhaus education buildings supports the growing consensus that the standard is the best way to ensure superior learning conditions, with teachers reporting a marked improvement in pupils' alertness and concentration.
This approach fits well with Sutton's ambitious sustainability targets, focused on a 'One Planet Living' strategy and incorporating the councils lowcarbon targets. Extensive public and authority consultation have helped to form the local infrastructure plans and improvements include encouraging staff, students and parents to choose sustainable transport, including buses, walking and cycling. 185 cycle parking spaces have been provided as well as shower and locker facilities.
Graham Thompson, Construction Manager, Willmott Dixon, said: "Very high levels of insulation are integral to Passivhaus. Where insulation boards abut there must be no gap, additionally the tolerance (air gap) behind and between can be no bigger than 3mm so quality needs to be outstanding. For example, the school's ground floor, set on concrete slabs, and CLT roof both required perfectly abutted insulation boards that met these extremely tight gap tolerances, through multiple layers with staggered joints. On the timberframed second and third storeys, insulation was pumped into the wall void to completely fill it.
"The design, labour and materials costs involved in delivering a Passivhaus building are slightly higher than for a conventional building. Currently, the uplift in cost is equivalent, or less, to building to BREEAM Outstanding, but when the savings on running costs are factored in, Passivhaus is significantly cheaper in the long run. On average, there is an additional 5-10% capital cost, however, this figure is expected to decrease as building regulations tighten and the volume of Passivhaus construction in the UK increases."
Architype's expertise in Passivhaus, alongside Willmott Dixons' flexibility in construction has helped to deliver a super low-energy building, with optimum internal conditions which hope to save as much as 90% on its heating bills and 70% on overall energy compared to standard newbuilds. Each room is served with a very small domestic scale radiator and light sensors to help students and teachers know how to use the room's minimal light and heating most efficiently. The school has achieved an exemplary air leakage score of 0.3ACH and is in the process of gaining Passivhaus certification.