A meeting of Northampton Borough Council’s planning committee this week voted in favour of the proposals by housebuilder Persimmon Homes, which would be sited on 208 hectares of mainly agricultural land.
In addition to the housing, the Dallington Grange scheme provides for 7.2 hectares of employment land, a new local centre with a 2,230 square metres of supermarket, offices, two primary schools, a secondary school, as well as landscaping and green spaces.
The site is allocated for major development in the West Northamptonshire Joint Core Strategy, adopted in 2014.
The officer’s report considered by the committee said the scheme provides for just 10 per cent affordable housing, compared to the core strategy's policy requirement of 35 per cent.
The council said it had subjected the developer's viability study into the proposals to its own independent analysis.
The report states: "It is disappointing to both officers and the applicant that the site is only able to achieve this reduced level of affordable housing provision and section 106 contributions."
The section 106 obligation will require Persimmon to provide 100 affordable units within the first 300 homes provided on the site, the report said.
It also includes a viabilty review mechanism that would mean the scheme is "re-valued at each phase of the development". "Should this revaluation demonstrate that the viability of the site has improved, the amount of affordable housing will be increased accordingly," it said.
"These viability issues must be weighed against the provision of much needed housing to meet the borough’s housing need and the associated New Homes Bonus, the early delivery of an element of affordable housing, and that the development will assist in the delivery of the North West Relief Road," officers said.
The application also provides for the retention of a Neolithic causeway in the west of the site, with a buffer of around 30 metres to the nearest construction.
The officer’s report said that mitigation measures "would ensure that any harm to heritage assets would be less than substantial, and that this harm would be outweighed by the public benefit of the delivery of a substantial amount of housing contributing to the borough’s housing need".
The report concluded: "The development of the site for up to 3,000 dwellings forms a significant and vital component of the borough council’s five-year housing land requirement and would contribute towards the government’s aims of improving economic development and the creation of employment and training opportunities.
"The site is located in a sustainable location on the edge of Northampton, which will be adequately served by the necessary infrastructure and it is considered that the environmental and highway impacts can be adequately mitigated or reduced to an acceptable degree."
The council has also inserted a condition requiring a detailed design code and masterplan to be produced by the developers before any reserve matters applications are granted.
Paul Burrell, executive director at Persimmon’s planning consultant Pegasus Group, said: "This is a large and important urban extension that will take a number of years to deliver."
Burrell said income from the Community Infrastructure Levy on the development would help pay for the planned Northampton North-West Relief Road, the secondary school and off-site sports provision.