Nightingale House at 65 Curzon Street, W1, has been put up for sale, paving the way for a £290m development opportunity.
DTZ Investors is selling the 40,249 sq ft office on behalf of the National Grid UK Pension Scheme, and is seeking offers in excess of £80m.
Two years ago, when prime central London values were at their highest, the building would have almost certainly been converted to residential.
However, a shortage of office space in Mayfair and concerns of an oversupply of luxury homes in the capital has led to it also being marketed as an office opportunity.
The existing building is currently let to a number of tenants but will be vacant by next year, creating the option for refurbishment.
Current office rents in Mayfair average between £80 and £90 per sq ft according to research from EGi. DTZ Investors has commissioned architects Pilbrow and Partners to produce massing and design studies for a new office-led mixed-use scheme of up to 52,250 sq ft.
Planning was given for a 32-home scheme at the beginning of the year, which also includes 9,000 sq ft of ground floor shops, a restaurant and arcade.
The arcade would restore a walkway between Stratton Street and Curzon Street that has been blocked since the 18th century.
The 32 flats would total 71,623 sq ft. Market experts estimated that new-build residential end values in Mayfair now stand at £4,000 per sq ft, giving a residential scheme an end value of £286.5m.
The Reuben Brothers’ nearby Carrington Street Car Park, W1, has a potential end value of £500m, while Brockton Capital’s 60 Curzon Street has an end value of £600m.
Residential agents from Savills and office agents from Savills and Colliers International have been appointed.
All parties declined to comment.
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