Each Development (an individual Development Contract) is for the provision of social housing units in the Westbank Derry Area by means of design and build, where the Developer provides the land, designs, constructs and completes the scheme for Apex in accordance with the DfC Housing Association Guide, Employers Design Brief and statutory body requirements. Apex will consider mixed tenure developments that is where some of the homes are designed and built to be social housing and some may be affordable standard homes. In the interests of providing an efficient housing management service, any one site must provide a minimum of 10 units. The developers proposals must ensure each site includes a range of house types. It is a normal assumption from NIHE that 10% of any development should consist of standard wheelchair accommodation. The estimated value is indicative only. The final contract value will depend on the site tendered, achievable development capacity, final approved housing mix and tendered Development Price per Unit. No minimum expenditure or contract value is guaranteed.