THE DEMOLITION of “Brighton’s best post-war building” is unjustified and wasteful, a leading conservation group has claimed.

A temporary fence was built up around the old Amex House in Eastern Road, Brighton, to signal the start of interior demolition work on the site with exterior work set to begin this summer.

The Regency Society has objected to the levelling of the iconic Wedding Cake offices and warned that its replacement could be an unworthy successor.

American Express said the demolition of the building, which opened in 1977 at a cost of up to £15 million, was required as part of the planning permission for the construction of the firm’s state-of-the-art HQ next door.

Under the 2009 s106 agreement for the new offices, demolition must begin on The Wedding Cake within six years of the start of construction of the new Amex offices which began in 2010.

The financial services giant launched a tender process for the sale of the Amex House site at the start of the year as part of redevelopment plans.

Under the City Plan, it is proposed the Edward Street Quarter would add up to 20,000 square metres of “high quality” office space, a minimum of 65 homes and cafes and restaurants.

A planning brief for the Edward Street Quarter, published in February 13, put the limit of any future buildings at seven storeys.

The Regency Society said they were unimpressed with initial proposals for The Wedding Cake’s replacement because it offers less employment space, supplies just 65 units of housing and its proposed green spaces would be “drab and unpleasant” in the shadow of tall buildings around them.

A society spokeswoman said The Wedding Cake’s demolition would be an “extravagant waste of environmental resources” considering the 45,000 tons of concrete and 4,000 tons of steel that went into its construction and 100,000 tonnes of chalk that had to be excavated for its foundations.

She added: “Our position has always been that there is no justification for its demolition.

“It is, arguably, Brighton’s best post-war building and offers a splash of style in Edward Street’s jumble of mediocrity.

“No reason has been offered for its demolition other than the original section 106 agreement.

An American Express spokeswoman said: “To meet timeframes required by the s106 agreement, American Express can confirm it has entered into a contract for the site clearance and subsequent demolition of Amex House.

“Work on the interior has commenced. Exterior works are expected to commence early summer this year.”