Tougher house-building standards need to be set by the Wales National Assembly to help curb its C02 emissions, conservationists have warned.

WWF, the global conservation organisation has published a report (Building a Future for Wales: A Strategy for Sustainable Housing), identifing key practices for designers, planners and developers to make energy efficient and low impact houses the norm in Wales.

It addresses ways to minimise carbon and waste emissions from homes, as around 27 per cent of all CO2 emission in the UK are produced through heating, lighting and appliance use in our homes.

The report also highlights ways to make houses more efficient in terms of their use of energy, water and materials.

"Unfortunately most houses in Wales have a negative impact on the environment because of the way they are designed and built. This guide offers key guidelines for ways to make homes more environmentally friendly," said Haf Roberts, Policy Officer for WWF-UK in Cardiff.

"Our current demands in Wales on the natural environment are excessive. If fact, if everyone in the world lived like the average Welsh person we would need nearly three planets to support our lifestyles," she added.

The report includes good examples of housing developments built to high environmental standards in Wales. One example is the Plas y Môr building at Burry Port which is an innovative care home that has many energy efficient features properly integrated into the design from the start to ensure affordability, which results in cost savings for the home over the long term.

Another example is in Butetown, Cardiff where solar thermal panels and flax roof insulation have been used on a new housing estate. This demonstrates what can be achieved by incorporating sustainability principles at a local government level.

The report identifies the following as important factors for building sustainable homes: energy efficiency appliances for heating and lighting; use of low allergy and environmentally friendly material; water efficiency through better sanitary fittings and drainage; provision for recycling and composting; and materials sourced from local or sustainable sources.

"Housing is a key element towards building a sustainable future, especially in terms of reducing carbon emissions and material waste," said Professor Phillip Jones, Head of the Welsh School of Architecture.

"We hope this guide will help pave the way for sustainable communities to be built in Wales."