The document, the City Fringe Opportunity Area Planning Framework, covers the area known as "Tech City", which attracts large numbers of digital businesses.
The framework, issued by London mayor Boris Johnson, says the availability of "plentiful cheap business space associated with the industrial legacy of the City Fringe has been one of the most significant factors in the rise of Tech City".
But it says many old warehouses "have now either been redeveloped or refurbished and competition for leases is increasing, as the core office market expands and more ‘traditional’ City businesses look to locate in the area".
The framework calls on developers to ensure that new schemes continue to include affordable employment floorspace and provide assurances that the space will be managed after construction and not converted to another use.
The document breaks the area up into three zones: an "inner core", an "outer core" area and "hinterland" areas.
In the inner core, it says proposals for new build employment floorspace will be encouraged and supported. It calls for "strong consideration" to be given to developing employment-led schemes and to opportunities to increase total employment floorspace through more intensive redevelopment of sites.
The document adds that in the outer core, mixed-use schemes "should still seek to provide significant employment floorspace where proposals include the demolition of existing employment floorspace".
In the hinterland areas, the document says, some employment floorspace may be appropriate but proposals are likely to be more residential in nature. "Consideration should still be given to supporting leisure and retail uses, particularly in areas where there is evidence of deficiency," it says.
The consultation closes on February 13.