Sir, North Oxfordshire Consortium complain about the proposal, made at this stage in the planning process, to designate the Cold War air base at Upper Heyford a conservation area (Report, March 31) and suggest that this could jeopardise the building of new housing.

The NOCL also express concern about the consultation process in which they say that the public, parish councils and council members may have been misled.

In fact the Cherwell council are only, if belatedly, meeting their legal duty to designate as a conservation area, this site of 'special architectural or historic interest.' Before NOCL bought the site they received a report from consultants, paid for by them (and CDC and English Heritage), that found Upper Heyford to be of international significance for the period 1950-1993.

The international significance was the part played by the military base in the Cold War, a power struggle in which the threat of nuclear holocaust and Mutually Assured Destruction was an essential part. I would challenge NOCL and the whole readership of this paper to say that the historic interest in this site is any less than any of the 250 conservation areas already designated in the county.

Such is the historic interest of the site that a decision taken by the council not to include it in a conservation area could be open to legal challenge.

The NOCL should know that the conservation area designation should not pose a threat to the provision of the 1,000 houses which have been allowed for in the Structure Plan specifically as a means to enable the military base and its Cold War associations to be conserved, together with environmental improvements.

This is the effect of the policy that was adopted prior to the sale of the site to NOCL and which must have been reflected in the price paid by them to the Ministry of Defence.

The legal effect of conservation area designation is that permission will only be granted for new development and environmental improvements which are desirable in preserving or enhancing the historic character or appearance of the site as a former Cold War air base. This means that the new housing (and jobs) will pay for the conservation rather than the demolition of buildings and structures within the base.

Frank Dixon, Oxford Trust for Contemporary History, Cholsey