House Builders Association tells planning minister Cooper of concerns that land supply will be undermined

Housebuilders have told planning minister Yvette Cooper that the rushed introduction of the Code for Sustainable Homes threatens to undermine the supply of land for housing.

Julia Evans, the chief executive of the House Builders Association, the trade organisation for smaller housebuilders, has written to Cooper to warn her that the way the code was being implemented would result in a "disorderly process of change that could affect output".

She said: "Most of our members buy land from private vendors … The combined fears of landowners about the planning gain supplement, increasing demands for affordable housing plus these potentially expensive local policies for sustainable development may leave private landowners with residual values that they will not accept. This could seriously affect land supply."

The letter says the impact of the tougher standards outlined in the code is uncertain, and it points out that many of the pilot EcoHomes projects were developed on sites subsidised by English Partnerships.

The letter expresses particular concern that the code would be interpreted in different ways by council planners. It cites as an example the introduction by Milton Keynes council planners of building standards that are more exacting than those enshrined in legislation.

There is a real danger that local planners will produce unviable policies

Julia Evans, HBA chief executive, in a letter to Yvette Cooper

"There is a real danger that planning authorities, unaware of technical issues and probably not even referring to building control sections in their own organisations, will produce unworkable and unviable policy requirements."

The letter warned that the introduction of uneven standards by councils would create confusion in the market and raised concerns about the untried nature of much eco-friendly technology.

The HBA is calling for Cooper's Department for Communities and Local Government to convene a summit to discuss the phased introduction of the code.

The publication of the letter follows the introduction by the Housing Corporation this week of its new EcoHomes XB standard.

The standard, which has been drawn up with BRE, extends the voluntary EcoHomes new-build standard to registered social landlords' stock for the first time.