Applicant Taylor Wimpey had applied to Canterbury City Council for hybrid consent for the scheme on a 55-hectare site at Sweechbridge Road, Herne Bay.
The application sought detailed consent for the first 193-home phase of the scheme, alongside access works, drainage infrastructure, open space, landscaping and street lighting.
Outline consent was sought for up to 707 additional homes, up to 27,000 square metres of employment space, a care home, local shopping facilities, a community centre, a school, open space, and associated infrastructure works.
Planning officers had recommended that the scheme be approved, with a planning report advising that the site "forms the major part of a strategic allocated site for a mixed-use development in the Canterbury District Local Plan".
It added: "The application site will provide a significant amount of the homes that are required to meet the district's need, as well as providing employment opportunities for local people. This application is therefore acceptable in principle."
The report advised that the proposals would fall short of local planning policy, which sought the provision of up to 33,000 square metres of employment space at the site, adding that this "reduced provision would need to be weighed against the benefits of the development overall".
But planners concluded that "the change to the landscape as well as the underprovision of employment floorspace will be outweighed by the significant public benefits of the proposed development on this strategic site allocated within the 2017 Local Plan".
However, members refused the proposals at a planning committee meeting yesterday (1 September).
A spokesman for the council said members had concluded that the scheme would not provide for "sufficient high quality open space for active and continual use due to the amount of that space which contains attenuation ponds/features" and would therefore be contrary to national planning policy.
Other grounds for refusal included that the development "at 40 dwellings per hectare is over-dense and would amount to an overdevelopment of the site given the location of the site".
Planners had avised that the proposed density "is considered appropriate in relation to existing surroundings".
In addition, the scheme's proposed 22.5 per cent affordable housing provision failed to meet the 30 per cent sought by local planning policy, "and there is no information about the distribution of affordable housing across the site as required by the local plan", the spokesman said.
Planning officers had accepted the results of a viability appraisal for the scheme which found that the scheme faced "high up-front infrastructure costs such as electricity connections for the strategic site, along with other factors including the requirement for a contribution to be made towards the funding of the Herne Relief Road to be secured by this application".
Members further found there there was a "lack of sustainable infrastructure such as solar panels and electric vehicle charging points", contrary to local plan policy, while "highways arrangements proposed would not provide safe movement within and around the proposed development".