5 Appraisal of quantum of development

Reasons for selecting the alternatives

5.1 At the JCS Examination Hearings the Inspector asked the JPU to consider the implications of two alternative plan period end dates, 2029 and 2031, in order to ensure at least a 15-year time horizon for the Joint Core Strategy in accordance with NPPF.

5.2 In preparing the objectively assessed housing need the JPU therefore sought to identify the housing and job requirements for the existing plan period end date of 2026 and the two alternative plan period end dates: 2029 and 2031.

5.3 The SA Addendum Scoping Report listed three options for the quantum of housing and jobs as a starting point, which were included in the draft Scope of Works[1] :

  • Option A (Housing) – 49,325 dwellings 2001-2026 (ONS 2011 + 3%), and (Jobs) - 21,635 jobs 2008-2026.
  • Option B (Housing) – 53,120 dwellings 2001-2026 (Short term migration), and (Jobs) – 24,506 jobs 2008-2026.
  • Option C (Housing) – 57,245 dwellings 2001-2026 (Toolkit 2008 + 3%), and (Jobs) – 27,627 jobs 2008-2026.

5.4 However, the SA Addendum Scoping Report noted that external consultants had been commissioned to carry out an objective assessment of housing and employment need rolling forward to 2029 and 2031, and therefore the above options have been superseded, Two external consultancies, Peter Brett Associates and the Cambridge Centre for Housing and Planning Research (CCHPR), were appointed by the JPU to carry out the objective assessment work. The results of those two studies are reported in the ‘Objectively Assessed Housing Needs’ paper July 2013[2] . These were used to finalise the options that have been subject to appraisal. Seven alternatives are considered in the Objectively Assessed Housing Needs paper, resulting in projected net additional dwellings shown in Table 5.1.

Table 5.1 Total net additional dwellings from 2011

 

Alternative

2011-2026

2011-2029

2011-2031

2008 DCLG Projections

39,480

46,388

50,720

Joint Core Strategy

33,780

40,536

45,040

Peter Brett 01-11 Trend

23,790

28,548

31,720

Peter Brett 06-11 Trend

22,320

26,784

29,760

Cambridge Return to Trend

35,745

41,580

45,240

Cambridge Tracking

35,385

41,760

45,740

ONS 2011 Extended

31,815

36,972

40,260

 

5.5 The JPU considered the results of the alternative projections and determined which should be taken forward for further work to inform the Proposed Main Modifications.  The Housing Paper explains the reasons for either rejecting or selecting the alternatives as ‘reasonable alternatives’:

  • The Peter Brett Associates projections were discounted, as they are considered to be too low compared to the latest official projections (2011 based Interim Projections) and do not therefore constitute the basis for a positively prepared plan in accordance with the requirements of the NPPF.
  • The 2008 DCLG Projections were discounted as being too high. This data set was largely discredited by the results of the 2011 Census, especially in the West Northamptonshire area where the 2011 Census results were demonstrably below the 2008 based projections; a position reinforced by CCHPR advocating use of the 2011-based information for West Northamptonshire over the 2008-based data behind the ‘What Homes Where’ Toolkit.
  • The remaining projections are all very similar in the scale of development they suggest. However, the JCS projections were discounted as they were produced on a dwelling constrained basis, and therefore do not comply fully with the currently understood definition of Objectively Assessed Housing Need.

5.6 Of the two CCHPR projections, the one which the JPU recommended should form the basis of the Objectively Assessed Housing Need for West Northamptonshire is the Cambridge Tracking projection. This was selected on the basis of the description of the methodology in the CCHPR report:

  • The CCHPR report admits that there is no particular science behind the alternative ‘Return to Trend’ option as the ‘half-way’ assumption has no real justification other than it is unlikely that there will be no move back towards trend and improbable that there will be a full return in the foreseeable future.
  • On the other hand, the Tracking methodology is based on the difference between the 2008 based projections for 2011 and the actual result as expressed in the 2011 Census, with this difference being maintained throughout the period of the CCHPR ‘Tracking’ projection.

5.7 In the JPU’s view, the only reasonable alternative to the Cambridge Tracking projection is the extended 2011 Census-based projection. This would give totals lower than the CCHPR totals but represents the latest official Government projections. Both the CCHPR and the extended 2011 Census-based projections give a significantly higher figure than the Peter Brett Associates recommended totals, although Peter Brett Associates indicated their belief that the 2014 based Sub-National Population Projections will be lower than the 2011 Census-based projections for West Northamptonshire. The JPU are therefore of the view that the 2011 Census-based projections could therefore be seen to represent an over-provision against what is expected to be in the next set of official projections, and could therefore be argued to represent positive planning for the area.

5.8 It is now expected that the Joint Core Strategy will be adopted in Autumn 2014.  The plan period in the JCS (as submitted) extends to 2026 which means that the time horizon from adoption is only 12 years.  The JCS (as submitted) provides a longer framework than 2026 in terms of the spatial vision which does not specify an end date, referring to “our vision of the future”.  However, since it has taken longer than originally anticipated to prepare the JCS and consequently the time horizon has been shortened from that originally intended.

5.9 Given the large difference in the projections provided by the JPU’s consultants, and the recommendations from both the Office for National Statistics and DCLG that neither the 2011 based projections or the 2008 based projections should be used for making projections beyond 2021, the JPU has real concerns about extending the Plan period too far.  Furthermore, as population and household projections are a key input to much of the evidence base, especially transport, education and community facilities, a shorter extension of the Plan period would better reflect the current evidence base.

5.10 Consequently, for the reasons set out above, the JPU are recommending that an extension of the Plan period to 2029 is preferable to an extension to 2031.

5.11 Given the extension of the end date of the plan period to 2029, and the decision by the JPU that the Cambridge Tracking alternative best reflects Objectively Assessed Housing Need, the quantum of development set out in the JCS as submitted is now out of date, and so this has not been subject to further appraisal.

5.12 Therefore, the two reasonable alternatives for the quantum of development over the extended plan period 2011-2029 that have been subject to SA in this Addendum are:

·         Cambridge Tracking, which represents the Preferred Choice of the JPU.

·         2011 Census-based projections (extended), which represents the reasonable alternative, but has been discounted by the JPU.

5.13 These two reasonable alternatives, showing the differences between the two, are summarised in Table 5.2 and Table 5.3 below.

Table 5.2 Net additional dwellings 2011-2029

Alternative

2011-2029

Difference (%)

Cambridge Tracking

41,760

 

ONS 2011 Extended

36,972

 

Difference

-4,788

-11%

 

Table 5.3 Net additional jobs 2011-2029

Alternative

2011-2029

Difference (%)

Cambridge Tracking

28,520

 

ONS 2011 Extended

26,849

 

Difference

-1,671

-6%

 

5.14 The difference in the number of homes between the two alternatives is 11% (equivalent to 266 homes per annum), which can be considered to be a material difference.  The difference in the number of jobs between the two alternatives is 6% (equivalent to 93 jobs per annum), which might be considered to be marginal in terms of whether or not this is material, given the time period under consideration.

5.15 Compared to the JCS as submitted, the Cambridge Tracking alternative and the ONS 2011 Extended alternative would result in an additional 7,980 dwellings and 3,192 dwellings respectively, albeit over a plan period extended by three years to 2029.  

1. West Northamptonshire Joint Core Strategy Local Plan (Part 1). Sustainability Appraisal Report Addendum – Scope of Works. West Northamptonshire Joint Planning Unit, April 2013. [back]
2. West Northamptonshire Joint Core Strategy. Objectively Assessed Housing Needs. West Northamptonshire Joint Planning Unit, July 2013. [back]

Approach to the appraisal

5.16 The two alternatives were divided into three options for the purposes of the appraisal.  The Cambridge Tracking option represents the preferred option that is presented in the Proposed Main Modifications to the JCS.  The other two options represent variants of the ONS Extended alternative, on the basis that this alternative could be delivered in two ways: first, by reducing the phasing by which development is delivered keeping the overall spatial strategy in the Proposed Main Modifications to the JCS including all the SUEs at all four towns; second, by reducing the number of SUEs needed, but developing the remaining SUEs at the same rate of delivery as in the Proposed Main Modifications to the JCS.

5.17 The three options appraised are therefore as follows:

  • Option 1 – Cambridge Tracking: This option assumes the delivery of 41,760 net additional dwellings and 28,520 net additional jobs over the period 2011-2029 in accordance with the Proposed Main Modifications to the JCS.
  • Option 2 – ONS 2011 Extended (reduced phasing): This option assumes the delivery of 36,972 net additional dwellings and 26,849 net additional jobs over the period 2011-2029 in accordance with the Proposed Main Modifications to the JCS, but with a slower rate of delivery.
  • Option 3 – ONS 2011 Extended (reduced SUEs): This option assumes the delivery of 36,972 net additional dwellings and 26,849 net additional jobs over the period 2011-2029 in accordance with the Proposed Main Modifications to the JCS, but with the deletion of between two and five SUEs (unspecified).

5.18 It should be noted that the amount of employment land to be delivered under all three options would be the same, taking into account that only about half of the jobs created under the options would be delivered on land allocated for employment, with the remainder in sectors such as retail, education, health, etc.  The new strategic employment site at Junction 16 included in the Proposed Main Modifications to the JCS would be required under all three options.

5.19 It should also be noted that the JPU was unable to indicate for Option 3 which SUEs would not be needed.  It was of the view that it would be much more likely for Option 2 to take place rather than Option 3, if the ONS 2011 Extended alternative were to be selected.  This is because:

  • In practical terms, the proposed build-out rates are very challenging for the Cambridge Tracking alternative, and might be difficult to achieve.  To build out over a longer period would help this, but removing one or more SUEs would maintain the challenging rates (and the increased risk of non-delivery associated with that).
  • In terms of spatial distribution, there are three main sectors where development is planned around Northampton: the north; the west and south west; and the south.  It would be important to maintain all these areas producing development otherwise the market in any of the other sectors could become swamped, and delivery fail.
  • Although the JCS plan period ceases in 2029, development will continue to occur after this, and therefore the strategy that is set now needs to stand the test of time beyond the plan period.  Therefore, keeping all the SUEs would allow both flexibility and certainty in planning how, in particular, the Northampton Related Development Area (NRDA) would develop over time.

5.20 Attempting to summarise the effect on each SA objective into a single appraisal score for each quantum of development is inevitably a challenge, given the different effects that could arise in different locations.  However, the approach is intended to give an overall indication of the effects that would be likely to arise, and to enable comparison between the three options.

5.21 The appraisal took as its reference point the findings of the appraisal of the Proposed Main Modifications to the JCS, and in particular the appraisals of the individual SUEs (Chapter 8) and strategic employment sites (Chapter 9), since these are where most of the planned development will be delivered.  Overall appraisal scores were assigned for each SA objective, taking into account the likely overall effect of the quantum of development and spatial strategy depending upon the option being appraised.

Summary of the appraisal findings

5.22 The findings of the appraisal of the three options are summarised in Table 5.4, and the full appraisal matrices are presented in Appendix 3

5.23 It can be seen from the summary table that the effects of the three options are likely to be similar.  This is not surprising, given that all three options would result in significant development, much on greenfield land.  Even Option 3, which would result in fewer SUEs, would still give rise to similar effects, with the potential exception of SA objective archaeology and cultural heritage (SA objective 2), given that it would still require the majority of SUEs to be developed, plus all the strategic employment sites identified as being needed under Options 1 and 2.  It would inevitably mean that the effects on the particular locations for the SUEs that would be removed from the Proposed Main Modifications to the JCS would no longer take place, but this would not be sufficient to alter materially the overall effects on the SA objectives as a whole.

5.23 A summary of the effects of the three options for each SA objective is described below Table 5.4.

Table 5.4 Summary of SA scores for the three options for the quantum of development

 

SA Objective

Option 1: Cambridge Tracking

Option 2:

ONS 2011 Extended (reduced phasing)

Option 3:

ONS 2011 Extended (reduced SUEs)

1.    Air quality and noise

+/-

+/-

+/-

2.    Archaeology and cultural heritage

--?

--?

-?

3.    Biodiversity, flora and fauna

+/--?

+/--?

+/--?

4.    Crime and community safety

0

0

0

5.    Education and training

++/-?

++/-?

++/-?

6.    Energy and climatic factors

0?

0?

0?

7.    Health and well-being

++

++

++

8.    Labour market and economy

++

++

++

9.    Landscape and townscape

+/--?

+/--?

+/--?

10.  Material assets

++

++?

++?

11.  Population

++

++?

++?

12.  Social deprivation

+

+

+

13.  Soils, geology and land use

-/0

-/0

-/0

14.  Waste

0

0

0

15.  Water

0?

0?

0?

 

SA Objective 1: Air quality and noise

5.25 All three options would generate significant amounts of traffic and associated emissions and noise.  While most development would not be in close proximity to AQMAs, it is likely that all three options would include at least some development within or close to AQMAs, or would generate journeys that would be in AQMAs, and therefore there is the potential for some negative effects.  Two of the employment land locations, which feature under all three options, could result in significant negative effects due to their proximity to the M1.

5.26 However, all three options would also come with measures to encourage the use of sustainable transport.

SA Objective 2: Archaeology and cultural heritage

5.27 All three options would be likely to have negative effects on the cultural heritage of the JCS area, due to the extent of historic interest, including listed buildings, archaeology and historic landscapes.  For five of the SUEs, these impacts could be significant, affecting in particular Options 1 and 2.  None of the strategic employment sites would give rise to significant negative effects.

5.28 There is the potential for reduced significance of negative effects on cultural heritage under Option 3, by the deletion of two or more SUEs that are most likely to result in the significant effects.

SA Objective 3: Biodiversity, flora and fauna

5.29 Under the individual appraisals of the SUEs and strategic employment sites, it was found that all of the SUEs and all but one of the strategic employment sites (Junction 16) could result in significant negative effects by virtue of their likelihood to affect locally designated sites and ecological networks, but that these effects would be partially offset by mitigation measures, and the creation of green infrastructure in association with development.  It is unlikely that there will be significant differences between the three options.

SA Objective 4: Crime and community safety

5.30 The effects of new development on safety, crime and fear of crime will depend on design proposals for development and factors such as the inclusion of open spaces that are overlooked by buildings to improve safety and security and sufficient lighting.  However, these issues will be determined though the detailed proposals for each development location, and therefore cannot be directly attributed to the quantum of development.

SA Objective 5: Education and training

5.31 It is likely that all three options would require investment in access to educational facilities, whether existing or new.  Overall, all three options would be likely to give rise to significant positive effects by the investment in the educational facilities on offer, albeit with some minor negative effects to reflect the fact that some existing educational facilities are not within easy walking distance of where new development would take place.

SA Objective 6: Energy and climatic factors

5.32 While all new development is likely to involve an increase in energy consumption over current consumption in West Northamptonshire, new development may offer good opportunities for incorporating renewable energy generation and it is assumed that new development will be built to high standards of energy efficiency.  The SUEs and strategic employment sites also offer the potential to incorporate renewable energy.  It is unlikely that there will be significant differences between the three options.

SA Objective 7: Health and wellbeing

5.33 It is likely that all three options would require investment in access to health facilities, whether existing or new.  The larger new developments would also offer opportunities to incorporate sport and leisure facilities.  New high quality housing and access to additional jobs would be likely to be good for health.  As a result significant positive effects are anticipated.  It is unlikely that there will be significant differences between the three options.

SA Objective 8: Labour market and economy

5.34 The difference between the two quantums of development in terms of jobs is not significant (representing less than 100 jobs per annum).  The JPU are of the view that around half of the jobs would be linked to locations where employment land is allocated, and the remainder would be in sectors such as retail, education, health, etc.  The amount of employment land to be allocated would be the same under all three options and would be sufficient to cater for the jobs growth forecast, giving rise to significant positive effects.  It is unlikely that there will be a significant difference between the three options.

SA Objective 9: Landscape and townscape

5.35 It is assumed that development within the urban areas would be sensitive to the townscapes within which they take place.  Nonetheless, all three options would require the development of greenfield land albeit with varying degrees of landscape sensitivity.  For nine of the SUEs under Options 1 and 2, the negative effects could be significant, although policies designed to ensure high quality design should offer some mitigation.  Only Junction 16 of the strategic employment sites could give rise to significant adverse effects.

5.36 There is the potential for reduced significance of impacts on the landscape under Option 3, by the deletion of two or more SUEs that are most likely to result in the significant negative effects, but this option would still require the development of SUEs and the Junction 16 strategic employment site that could result in significant negative effects, although also partially offset by mitigation.

SA Objective 10: Material assets

5.37 All three options would deliver significant numbers of additional dwellings, including affordable homes.  This would result in significant positive effects.  However, if Option 1 (Cambridge Tracking) proves to be the most accurate of the two quantum alternatives, this introduces uncertainty whether Options 2 and 3 (ONS 2011 Extended) would deliver enough housing to meet all the identified needs.

5.38 All three options would deliver well-designed development that makes efficient use of land and should help to support viable services and sustainable modes of transport.

SA Objective 11: Population

5.39 All three options would deliver significant numbers of additional dwellings, and the scale of development would offer opportunities to provide a range of type and tenure of dwelling, including affordable homes.  This would result in significant positive effects, although there would be an element of uncertainty under Options 2 and 3, should the ONS 2011 Extended alternative prove not to be as accurate as the Cambridge Tracking alternative in forecasting need.

SA Objective 12: Social deprivation

5.40 The scale of development under all three options would allow for investment in a range of community services and facilities, and would also provide for the creation of jobs, which could help to address deprivation problems.  The effects are likely to be minor positive given that other Government policies not linked to land use planning are likely to have a greater influence.

SA Objective 13: Soil, geology and land use

5.41 Few of the SUEs and none of the strategic employment sites would result in significant negative effects on this objective.  There are two SUEs under Options 1 and 2 (Northampton North and Daventry North East) that could result in significant negative effects due to the potential for development on Grade 2 agricultural land and in the case of one SUE (Daventry North East) there are potential land instability issues.

5.42 Option 3 could avoid such issues by not providing for development at the SUEs concerned, but one of the SUEs concerned is Daventry North East SUE, which would be likely to come forward under all three options.

5.43 As a result, all of the options are likely to have similar effects.

SA Objective 14: Waste

5.44 The potential effects of development on waste generation will be influenced by their design and use and the incorporation of sustainable waste management measures.  Therefore, development by itself is likely to have a negligible effect on this objective.

SA Objective 15: Water

5.45 A Phase 1 Water Cycle Study was undertaken on the basis of the proposed housing development included in the East Midlands Plan, being 62,125 net additional dwellings for the period 2001-2026 in the West Northants JCS area.  The Phase 1 Water Cycle Study found no significant constraints to that level of growth with respect to water resources and waste water treatment, subject to appropriate investment and changes to discharge consent licences.

5.46 Phase 2 of the Water Cycle Study was prepared at the time of the Pre-Submission JCS, which planned for 50,150 dwellings to be delivered over the period 2001-2026, of which 15,680 had been completed between 2001-2010, leaving 34,470 left to deliver 2010-2026.  The Phase 2 Water Cycle Study found no significant constraints to delivering the development in the Pre-Submission JCS in terms of water resources, subject to implementation of the Code for Sustainable Homes and Building Regulations standards.

5.47 The Phase 2 Water Cycle Study did not identify significant constraints with respect to waste water treatment capacity, although it was noted that additional licences and investment in infrastructure would be required.  However, the Water Cycle Study raised issues with respect to compliance with the Water Framework Directive (WFD), with regard to phosphates linked to the quality of treated wastewater discharge.

5.48 Although the JCS plan period is to be extended by three years to 2029, the total amount of housing to be delivered under Options 1, 2 and 3 will still fall short of what was proposed in the East Midlands Plan.  Nonetheless, Option 1 would deliver 7,980 more dwellings than the Pre-Submission JCS, and Options 2 and 3 would deliver 3,192 more dwellings than the Pre-Submission JCS.

5.49 On the basis of both the Phase 1 and Phase 2 Water Cycle Studies, it is not thought that there will be water related issues with respect to any of the three options.  However, given the increase in development over that proposed in the Pre-Submission Core Strategy, and the potential issues regarding meeting WFD objectives, there is some uncertainty over this conclusion.

5.50 All three options should be able to be delivered without significantly increasing the risk of flooding, particularly if sustainable drainage systems (SuDS) are integrated into the overall design.

 

Reasons for selecting the preferred alternative

5.51 The JPU has selected the Cambridge Tracking (Option 1) as the preferred alternative to act as the basis of the Proposed Main Modifications to the JCS, because it is the alternative that the JPU is most confident in placing reliance upon with respect to methodology, taking into account the requirements of the NPPF.

5.52 The JPU has rejected the ONS 2011 Extended reasonable alternative (which formed the basis of Options 2 and 3), since it is less  confident that it will pass the NPPF test of Objectively Assessed Housing Need, compared to the Cambridge Tracking alternative.