The tougher green design and planning standards announced by the government last week for eco-towns are laudable, but far from radical. They can be achieved without too much trouble, and few of them represent real cutting-edge thinking on sustainability. Perhaps most underwhelming is that the standards apply only to eco-towns: many of the targets proposed by the government last week should be the aim for all new housing development.

The government wants the average house in an eco-town to be within a 10-minute walk of frequent public transport and neighbourhood services. It wants one worker in every home to be able to get to their job by walking, cycling or catching public transport. It wants every eco-town building - whether commercial, public or residential - to achieve a zero carbon rating. Those targets are already achievable for nearly all of the 3m new homes the government wants built by 2020. If we are to achieve a sustainable future, targets need to be mandatory across the board.

To get real about delivering sustainable housing, we need to build the right homes in the right places, which encourage sustainable lifestyles. That means building homes that don't burn fossil fuels and putting homes in locations where residents can leave their cars at home or choose not to own a car at all. It means becoming less rigid about separating where we work from where we live. While this may seem idealistic, it is attainable.

A radical approach not seen in the eco-towns programme is necessary to take the green housing agenda further. The day before ministers announced the eco-town standards, Liberal Democrat MP Matthew Taylor released his report on rural communities. Among his recommendations he called on local authorities and the government to promote "live/work quarters", which give people workspaces in and around the buildings they live in. In the past, planning often separated living from hazardous industrial employment, but we work in different and l argel y cleaner ways now. The need to separate home from work is becoming less relevant.

From an environmental point of view the advantages of live/work are obvious. It means less commuting and the sharing of resources, which would normally be doubled up at home and the workplace. In lifestyle terms, it's also good, giving people more time for family, friends and recreation. A truly radical green housing agenda should maximise these benefits, but the new eco-town standards largely pass them by.

The government should act straight away to generalise its new standards. Greater environmental benefit could be achieved by applying eco-town standards to urban expansion projects, redevelopment and urban regeneration. Achieving the government's housebuilding targets would often be easier in these types of developments anyway, because the most efficient use could be made of existing infrastructures.

New homes would be close to schools and hospitals and close to retail services, enterprise and employment. Existing urban and suburban areas are where most of us live already. If we cannot green them, then eco-towns will be of only marginal environmental benefit.

The government needs to act now to shift from an eco-towns' policy to an eco-quarters' policy. It needs to generalise as many green standards as possible and test new ways of greening our existing homes and enhancing their relationship with work and the economy.