by Katie Thornburrow

One of a series of guides for those working with architects

‘Sustainable development is ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs.’ Brundtland Commission, 1987

‘Sustainable development is the only thing that stands between us and an utterly miserable descent into ecological collapse, resource wars, worsening inequity and social implosion.’ Jonathon Porritt, Sustainable Development Commission

Sustainability is a first principle at Granta Architects. We do not have special ‘sustainability’ projects, because we work to incorporate sustainability into everything we do.

A sustainable building has low carbon emissions and water consumption.

It is designed for minimum waste in construction, reusing or recycling building materials where appropriate.

It is durable, and designed to be flexible to accommodate changing needs.

It is inclusive, allowing good access to facilities for the community and people with disabilities.

Its grounds and landscaping promote bio-diversity and wildlife.

Its design and location encourage sustainable forms of transport, and discourage car use.

Granta Architects is committed to incorporating sustainability into every facet of the practice — in our lives, our work environment, and our projects. We consider the whole lifecycle of the building and work to merge environmental and economic considerations throughout our work.

Our buildings use sustainable materials, with a focus on reuse, waste minimisation, and recycling. Our designs are economical to operate, incorporating a variety of heating, cooling and lighting mechanisms.

Finally, we approach sites with a view toward sustainable lifestyles — creating buildings and communities that allow residents to walk, cycle or drive; that have space for gardens; and that cater to residents at all stages of life.

At Garden Walk we worked to rehabilitate a former furniture workshop into a garden flat, using existing materials where possible and introducing solar panels, mechanical ventilation heat recovery, and sustainable landscaping to minimise the environmental impact of construction and to ensure that the building can be operated sustainably, as a home or ancillary dwelling.

In Kirtling, we have worked with the Fairhaven Estate to develop starter homes with low operating costs that allow residents to reduce their reliance on cars and help support a vibrant village community. We have also worked to design appropriate infill development and to reuse existing structures elsewhere in the village.

Sustainability must be addressed at all stages of the process of building, renovating or occupying a building.

Construction has a major role to play in sustainable development. Buildings are responsible for nearly half of the energy used and carbon dioxide emissions produced in the UK. Huge quantities of materials are used every year for new buildings and refurbishing older buildings, and around a third of all waste material sent to landfill sites comes from construction and demolition.

Every new building increases the pressure on the natural environment — because of land-take, new demand for energy and water in use, consumption of natural resources for materials, and the waste arising during construction.

With thoughtful construction, new buildings can use energy and water efficiently, and can bring back into use land and buildings that have been abandoned. Even buildings that look beyond repair may often be reconstructed.

Local sourcing of materials and labour can greatly cut the transport (and associated emissions) generated by construction. We try to exploit the local skill base, preserving traditional skills, keeping construction work in the local area and drawing on the expertise of local consultants. This both minimises the environmental impact of transport and helps to preserve local skills.

Choosing less hazardous materials and energy-efficient construction methods also help protect the environment. Choice of materials is crucial to the efficiency of a new or renovated building.

We can all help to address climate change by cutting the carbon dioxide produced in existing buildings. Architects have a moral obligation to provide house-owners with information that allows them to make decisions about sustainability within their financial constraints. When new building work is combined with refurbishment, potential energy savings from improving the existing building usually exceed the gains achievable in new buildings.

This is a vitally important aspect of improving the sustainability of our national building stock. Whereas there are 26 million dwellings in the UK, only 160,000 new homes are built each year. Improving the energy efficiency of existing dwellings can have more impact on the nation’s energy use.

When we create a new building from an old one, we re-use as much of the original building material as possible. We design for energy-efficient use throughout the lifetime of the building, integrating efficient and sustainable energy sources with maximum insulation to make sure that all energy is put to good use.

Sustainability and energy efficiency rely on practices and behaviour after work has been completed as well as during building. No amount of careful planning at the construction stage will prevent occupants leaving devices on standby or leaving on lights or heating in empty rooms

Commitment to sustainable development must be carried through into sustainable living. This can mean changes in lifestyle and working practices. Siting work areas where natural light falls, using lower-energy equipment (such as laptop rather than desktop computers) and making careful use of energy help make the most of a building.

Simple measures such as using small pans to cook, keeping doors closed, using shutters and fitting heavy curtains help to cut energy use. There is more advice on how to live sustainably in the section “What can I do?”

The energy used to heat space and water, to light buildings and power appliances accounts for 44% of the carbon dioxide emissions produced in the UK. Energy efficiency and use of renewable energy sources cuts costs and carbon emissions. We strive to minimise use of energy during construction, and to use energy-efficient materials and processes. We can assess and advise on opportunities for generating renewable energy on site, using solar water heating, wind turbines, biomass heating, photovoltaics or ground-source heat pumps.


The highest standards of insulation and draught-proofing ensure that minimal energy is needed to heat a building, cutting costs and carbon emissions. The better insulated your home or building, the less energy you will need for space heating.

The quality and size of doors and windows and the building’s ‘airtightness’ affect energy efficiency. If warm air can leak out of gaps in the structure, the building will be less energy efficient.

The movement of air is generally more important than the temperature in a room. Keeping air moving makes a room more pleasant in warm weather, and cutting drafts makes it feel warmer in cold weather.

There are four main groups of insulation materials:

Natural insulation (e.g. sheep’s wool, cork, flax).

Recycled cellulose insulation (e.g. Warmcell — recycled newspapers).

Mineral insulation (e.g. Rockwool, foamed glass, expanded clay).

Petrochemical insulation (e.g. Polyurethane, polystyrene).

From an environmental point of view, natural materials are the best and petrochemical materials the worst. Our insulation guidelines give more information.

Renewable energy

Renewable sources of energy and efficient use of energy minimise the environmental impact of a building. We can advise on fitting solar and wind harvesting technologies and ground heat extraction systems.

For many buildings, the quickest and easiest way to switch to a renewable source of energy is to install a biomass boiler. Biomass boilers use a non-fossil fuel, usually woodchips or pellets produced as waste by the timber industry.

They are essentially carbon neutral, as the carbon dioxide released by burning them has recently been absorbed from the atmosphere while the trees were growing. There is more about sustainable energy sources in our information sheet on renewable energy.

Solar power technologies fall into two categories: solar-heated water and photovoltaics (to provide a source of electricity). Solar water heating is cheaper and easier to fit than photovoltaics.

Passive heating uses solar heat to warm a building at no cost and without using technology. With thoughtful orientation of walls and windows and appropriate materials, natural heat can provide 30% of the building’s heating requirement. The building absorbs heat during the day and releases it slowly at night.

Over-heating from the sun can also be a problem. A poorly designed conservatory used as a living room can become too hot in the summer and too cold in the winter.

Everyone can take some steps to improve the sustainability and efficiency of their buildings and lifestyle. Even the tiniest steps help. If your building was not designed with sustainability in mind, even quite simple steps can make a big difference to the efficiency of the building and the sustainability of your lifestyle.

There are many simple steps you can take that cost nothing…

It’s sensible to make changes to your lifestyle that cost nothing before planning to invest in larger changes. Some people can reduce their carbon footprint by 10–20% just by taking measures that cost nothing at all. Some of these changes even save money! There are more ideas in our downloadable list of sustainability guidelines.

· Dry clothes outside

· Turn off lights you’re not using and don’t leave appliances on standby

· Turn down room and hot water thermostats by 1 or 2 degrees

· Review the times your heating and hot water come on and off

· Don’t boil more water than you need in the kettle

· Wait for a full load before running the washing machine or dishwasher

· Take a shower rather than a bath

· Keep the freezer de-frosted and position it in the coolest possible place

· Close curtains at dusk and make sure they don’t block the radiators

· Put a bottle of water in your WC cistern so it uses less water to flush

· Compost food waste for use in the garden, use washing-up water to water the garden, and grow your own fruit and veg

· Think twice before you buy things and make sure you actually need any new items.

For a small outlay, you can do a little more to help…

When you have done all that you can for free, think about actions that cost relatively little and will soon recoup the initial outlay. Some of these are best taken when you are making changes anyway; others can be made at any time.

· Dry-line and insulate external walls and insulate any uninsulated cavity walls

· Draught-strip all external doors and windows and seal gaps around pipes, cat-flaps, etc.

· Put foil panels behind radiators on external walls and fix shelves above radiators

· Make sure your hot-water tank has at least 75mm of insulation, insulate hot water pipes and increase loft insulation to 270 mm

· ‘Shrink-wrap’ single-glazed windows for winter and install DIY secondary glazing on appropriate windows

· Look for high-performance double- or triple-glazed windows and doors

· Fit a water butt to collect rainwater for gardening

· Look for the EU energy label whenever replacing electrical goods; on unrated appliances (TVs, Hi-Fi for example), ask about energy efficiency

· Choose a condensing boiler and upgrade controls, radiator valves and the hot water cylinder

· Upgrade light fittings to take low energy bulbs

· Choose a wood-burning stove rather than an open fire

· Use FSC timber, natural insulation materials like sheep’s wool, flax and hemp, natural fibres for floor coverings and organic, low-solvent paints.

If you are ready to spend more and take expert help, you can make big changes…

More ambitious actions may not recoup the outlay needed in savings, but you may choose to take these steps if you really want to do your bit to combat climate change.

· Install solar panels for hot water or photovoltaic solar panels for electricity

· Dry-line and externally insulate all external walls

· Install bio-fuel heating e.g. woodchip boiler or wood-burning stoves

· Replace all windows with high performance, double-glazed units

· Install your own wind-turbine

· Insulate underneath the ground floor

· Fit a composting loo

· Install a rainwater harvesting system

· Create a turf or sedum roof

· Install a ground source heat pump.

Our Approach

Granta Architects works with private individuals, corporate clients and public sector bodies to produce sustainable developments fully compliant with the requirements of conservation. We are always sensitive to the architectural and natural environment as well as to the needs of the client.

Published by Granta Architects Ltd, 12D Kings Parade, Cambridge, CB2 1SJ

For further information please contact us. Email or phone +44 1223 565656

Granta Architects is an RIBA Chartered architectural practice based in Cambridge, UK.

Granta Architects is an RIBA Chartered architectural practice based in Cambridge, UK.