Sussex sustainability specialist Mark Pellant of Koru Architects explains how

Six years ago our practice won a prize for a sustainable school entry in an RIBA ideas competition for Kingsmead Junior School in Canterbury. Our innovative school design exploited the best solar orientation, it boasted super-insulation, rainwater harvesting, solar thermal heating, renewable electricity generation from a wind turbine and photovoltaic array and it attempted to create a healthy internal environment for both children and teachers by using natural, non-toxic materials and finishes.

All these technologies and products have been around for some time and, as well as proving to deliver benefits that will reduce energy and water costs, they will also create a better, more healthy environment for teaching and learning. Unfortunately very few new school buildings and refurbishments have been designed with sustainability as a priority, but thankfully the Government has now introduced it’s ‘Building Schools for the Future’ initiative which finally puts social and environmental sustainability at the heart of it’s funding policy and empowers schools to become greener.

If you are about to embark on a sustainable school building or refurbishment project we would strongly advise an holistic approach that both encompasses the existing school buildings and carefully identifies the school’s future building requirements so that a long term sustainable building strategy can be formulated.

Design for a truly sustainable school building needs to consider a wide range of environmental issues, many of which are less obvious, but can make an equal or greater impact than the ‘seen-to-be-green’ solutions that grab the headlines. Although visible gestures such as wind turbines and photovoltaic arrays are desirable, it is often more sustainable to address some of the less visible aspects such as insulation and air-tightness before looking at alternative energy generation.

Below are some of the issues an environmentally sustainable school building can address with solutions we believe should be considered and then prioritised to offer the most effective environmental solution and value for money.

Reducing carbon emissions

Buildings account for half of all CO2 emissions and as a priority energy should be conserved and efficiency should be addressed. A thoughtful design can easily exploit the sun’s passive heating effect in winter by considering solar orientation and can also control overheating in summer by incorporating solar shading and thermal mass. Thermal insulation and air-tightness can be greatly increased to exceed current (minimum) Building Regulation standards and is a very cost-effective way to conserve energy and reduce heating or cooling demands. A sustainably designed building can maximise natural daylighting to reduce electric light use, and with low energy light fittings can reduce electricty consumption still further. A less obvious way of shrinking a new building’s carbon footprint is to construct it from materials that are low in ‘embodied energy’, that means to say minimal energy in production and transportation and sourced or grown locally.

Once energy conservation and efficiency measures have been incorporated into the design of a new school building then renewable energy generation can sensibly be considered. The first technology that deserves serious attention is solar thermal to supplement space heating and hot water which can be very efficient and have a pay-back time of only a few years. Next, in our opinion, would be a combined heat and power (CHP) system capable of producing both electricity and hot water which could be either gas-fired or, to be really green, be powered by wood chips or biomass. Consideration could also be given to photovoltaic panels, wind turbines (if on a consistently windy site) and small hydro-power (if near a river) to generate renewable electricity.

Reducing water shortages and flood risks

The priority is once again conservation and efficiency by specifying ‘reduced-flow’ aerating taps with sensors and low water-use appliances such as dual-flush WCs and waterless urinals. The next step would be to consider a rainwater harvesting and storage system where filtered rainwater can be used to flush toilets thus saving over one-third of the building’s water consumption.
Flood risks can be reduced by careful design of the external landscape to minimise ‘hard’ surfaces and by creating more ‘soft’ landscaping that will absorb rainfall. ‘Green’ or sedum roofs can also have the same effect with the added benefit of encouraging insects and birds to thrive.

Creating healthy teaching environments

The internal environment in many buildings is often more polluted than the external environment and for this reason internal finishes should be chosen with care. We always suggest using healthy, natural materials and finishes such as mineral paints, wool carpets, linoleum, cork and minimises the use of synthetic, allergy prone materials such as nylon carpets, oil-based paints, vinyl and plastics which can contain carcinogens and can continue to ‘off-gas’ toxic chemical vapours for months after installation. By choosing natural products the environment is further protected as these materials are non-toxic and biodegradable so won’t cause harm to the environment during manufacture or at the end of their useful life.

To improve the internal environment of a new building still further we recommend using a ‘breathing wall’ construction with natural insulation such as wood fibre, recycled newspaper or sheep’s wool which allows excess moisture to move through the walls thus creating more comfortable internal environments and humidity levels.

Although environmental sustainability is a complex issue with many factors and interactions that need to be considered, there are now many more sustainable building materials available and many more specialist architects available to advise on the most appropriate and sustainable solution for our school buildings.

Koru Architects are members of the AECB (Association of Environment Conscious Building) and the Green Register of construction professionals and have a strong commitment towards designing sustainable buildings and refurbishments.

For more information please contact Koru Architects on 01273 204065