Key Issues: Site Capacity
5.1 Summary
The Local Plan proposes 3,500 houses to be built on Bourn Airfield, a figure originally proposed by the developer. The site is too small to accommodate this many houses at a density that is compatible with the council's own policies on housing density for new developments in rural areas. The council appear to have made significant mistakes in their calculation of the site’s capacity.
5.2 Historical precedent
5.2.1 In 1992 Bourn Airfield was considered as a potential site for the new settlement of Cambourne. The Planning Inspector, Mr T Kemmann-Lane, submitted a report in which he drew particular attention to the “generally small and cramped nature of the
site”. [29] He observed “the Bourn Airfield proposal does lack sufficient room within its boundaries to give adequate separation [from Highfields Caldecote]”. [30] Similarly, he thought the proposal (for only 3,000 dwellings, rather than the currently-proposed
3,500) “would produce a tight development”.31 This was prior to the building of Cambourne, and Highfields was less than half its present size. In addition, the A428 was not a dual carriageway in 1992, which has also reduced the size of the Bourn Airfield site by 10 ha.
5.3 Flawed estimation of capacity and density
5.3.1 The Local Plan proposes 3,500 houses on the Bourn Airfield site. This is based on the revised SHLAA, which states that “the built area of the new village within the major development site (of 141.7 ha) will be established through an Area Action Plan
(hereafter AAP) for a wider area of 282 ha to also provide required strategic landscaping”. SCDC planning documentation shows that high-level verification of the site capacity did not distinguish between these two areas (see Appendix A).
5.3.2 The SHLAA goes on to state that “a gross to net residential area of 40% (is applied to the AAP) which allows for all non-residential uses and substantial strategic landscaping in the remaining 60%”. This indicates that a total of 40% of the 282 ha AAP area, totalling 112 ha, will be used for residential development, all of which will be within the major development site. This leaves only 28 ha to accommodate all nonresidential development. In addition, the high-level verification did not recognize that a considerable amount of the 141.7 ha major development site needs to be given over to landscape buffering, green spaces, infrastructure or community structures (see Appendix B), all of which must also be provided from within this 28 ha. As a result the
capacity of the site has been significantly over-estimated.
5.3.3 The site is very tight. It is bound by the A428 to the north and is set between the settlements of Cambourne and Highfields Caldecote to the west and east respectively. There are protected buildings to the south-west of the site and an industrial unit to
the north-east of the site which require landscape buffering. A large spur of land to the north-east is included in the development site, but can only be used for an access road and not for housing. The area that will provide green space to the community and give it a supposed ‘rural character’ is isolated to the south of the site.
5.3.4 The constraints of the site mean that a significant part of the major development site must be given over to landscape buffering. In addition, SCDC proposes extensive infrastructure and community facilities including a Park and Ride facility, employment and retail space, a medical centre, 4-5 schools and other community buildings. When extensive landscaping, open spaces, the Park and Ride, and the essential community infrastructure and facilities are taken into account we estimate the area available for housing is, at most, 85 ha. In Appendix B a detailed justification of this figure is given, which provides a more detailed analysis than that undertaken by SCDC and without its mistaken assumptions.
5.3.5 At an early stage in the consultation process, the Stop B.A.D. campaign identified significant flaws in the presentation of the Bourn Airfield site in the SHLAA. The area of the development site, the density of housing and the housing estimation could not be
reconciled. We pointed this out to SCDC and, as a result, the SHLAA was revised and republished and the consultation period was extended. We have demonstrated in Appendix B that SCDC’s figures and analysis are still flawed and the scale of the proposed development is not feasible.
5.4 Conclusion
The Local Plan proposes that Bourn Airfield can accommodate 3,500 houses in a beautifully-landscaped site, with a Park and Ride facility, green spaces, retail, employment, schools etc. - all in a smaller area than was deemed ‘small and cramped’ for 3,000 houses twenty years ago. Detailed examination of the site demonstrates that Bourn Airfield simply cannot deliver 3,500 dwellings and this threatens aspects of the site’s sustainability and the viability of community infrastructure such as the secondary school. With a density of 30 dph, comparable to Cambourne and appropriate for a rural area, the site can only accommodate 2,550 dwellings. Even at this size Bourn Airfield will be nothing more than a single, densely-packed housing estate, shoe-horned into a cramped parcel of land, with the green space of the AAP being merely a mathematical convenience rather than a benefit to the residents.
The Local Plan proposes 3,500 houses to be built on Bourn Airfield, a figure originally proposed by the developer. The site is too small to accommodate this many houses at a density that is compatible with the council's own policies on housing density for new developments in rural areas. The council appear to have made significant mistakes in their calculation of the site’s capacity.
5.2 Historical precedent
5.2.1 In 1992 Bourn Airfield was considered as a potential site for the new settlement of Cambourne. The Planning Inspector, Mr T Kemmann-Lane, submitted a report in which he drew particular attention to the “generally small and cramped nature of the
site”. [29] He observed “the Bourn Airfield proposal does lack sufficient room within its boundaries to give adequate separation [from Highfields Caldecote]”. [30] Similarly, he thought the proposal (for only 3,000 dwellings, rather than the currently-proposed
3,500) “would produce a tight development”.31 This was prior to the building of Cambourne, and Highfields was less than half its present size. In addition, the A428 was not a dual carriageway in 1992, which has also reduced the size of the Bourn Airfield site by 10 ha.
5.3 Flawed estimation of capacity and density
5.3.1 The Local Plan proposes 3,500 houses on the Bourn Airfield site. This is based on the revised SHLAA, which states that “the built area of the new village within the major development site (of 141.7 ha) will be established through an Area Action Plan
(hereafter AAP) for a wider area of 282 ha to also provide required strategic landscaping”. SCDC planning documentation shows that high-level verification of the site capacity did not distinguish between these two areas (see Appendix A).
5.3.2 The SHLAA goes on to state that “a gross to net residential area of 40% (is applied to the AAP) which allows for all non-residential uses and substantial strategic landscaping in the remaining 60%”. This indicates that a total of 40% of the 282 ha AAP area, totalling 112 ha, will be used for residential development, all of which will be within the major development site. This leaves only 28 ha to accommodate all nonresidential development. In addition, the high-level verification did not recognize that a considerable amount of the 141.7 ha major development site needs to be given over to landscape buffering, green spaces, infrastructure or community structures (see Appendix B), all of which must also be provided from within this 28 ha. As a result the
capacity of the site has been significantly over-estimated.
5.3.3 The site is very tight. It is bound by the A428 to the north and is set between the settlements of Cambourne and Highfields Caldecote to the west and east respectively. There are protected buildings to the south-west of the site and an industrial unit to
the north-east of the site which require landscape buffering. A large spur of land to the north-east is included in the development site, but can only be used for an access road and not for housing. The area that will provide green space to the community and give it a supposed ‘rural character’ is isolated to the south of the site.
5.3.4 The constraints of the site mean that a significant part of the major development site must be given over to landscape buffering. In addition, SCDC proposes extensive infrastructure and community facilities including a Park and Ride facility, employment and retail space, a medical centre, 4-5 schools and other community buildings. When extensive landscaping, open spaces, the Park and Ride, and the essential community infrastructure and facilities are taken into account we estimate the area available for housing is, at most, 85 ha. In Appendix B a detailed justification of this figure is given, which provides a more detailed analysis than that undertaken by SCDC and without its mistaken assumptions.
5.3.5 At an early stage in the consultation process, the Stop B.A.D. campaign identified significant flaws in the presentation of the Bourn Airfield site in the SHLAA. The area of the development site, the density of housing and the housing estimation could not be
reconciled. We pointed this out to SCDC and, as a result, the SHLAA was revised and republished and the consultation period was extended. We have demonstrated in Appendix B that SCDC’s figures and analysis are still flawed and the scale of the proposed development is not feasible.
5.4 Conclusion
The Local Plan proposes that Bourn Airfield can accommodate 3,500 houses in a beautifully-landscaped site, with a Park and Ride facility, green spaces, retail, employment, schools etc. - all in a smaller area than was deemed ‘small and cramped’ for 3,000 houses twenty years ago. Detailed examination of the site demonstrates that Bourn Airfield simply cannot deliver 3,500 dwellings and this threatens aspects of the site’s sustainability and the viability of community infrastructure such as the secondary school. With a density of 30 dph, comparable to Cambourne and appropriate for a rural area, the site can only accommodate 2,550 dwellings. Even at this size Bourn Airfield will be nothing more than a single, densely-packed housing estate, shoe-horned into a cramped parcel of land, with the green space of the AAP being merely a mathematical convenience rather than a benefit to the residents.
References:
29 Inspector’s Report §21.2.12
30 Inspector’s Report §21.2.5
31 Inspector’s Report §21.2.13
29 Inspector’s Report §21.2.12
30 Inspector’s Report §21.2.5
31 Inspector’s Report §21.2.13