Policy information sourced from the Welwyn Hatfield Local Plan

SP 23 Marshmoor Policy Area - SDS7 and wider area

A Supplementary Planning Document for the Marshmoor Policy Area, informed by the Strategy Diagram in Figure 15 below, will be prepared to guide development of SDS7 and other land within the wider Marshmoor Policy Area, which are both defined on the Policies Map. The final quantum and phasing of development within SDS7 will be set out within the Supplementary Planning Document.

Site SDS7 is allocated for a mixed use development comprising 40,500sqm of Class E(g) employment floorspace and 100 no dwellings (Class C3) providing affordable accommodation for those employed on the site. It is intended that this site will primarily be for employment and that the accommodation will form part of the offer of the site to business users, helping them to attract skilled employees and thereby assisting in bringing jobs to this site at an early date. To ensure that this link is retained, the accommodation requirement will be secured through a planning condition or a legal agreement. Once completed, all new Class E(g) development on SDS7 will be afforded the same policy protection as that provided by Policy SADM10.

Development proposals within site SDS7 and the Marshmoor Policy Area will be expected to be consistent with the Supplementary Planning Document, and as a minimum will also be required to comply with the provisions and guidelines set out below:

Access and movement

  1. The primary vehicular access into SDS7 should be taken from the Dixons Hill Road/A1000 roundabout;
  2. A new secondary vehicular access, or the intensification of an existing access, onto the A1000 to serve SDS7 will only be supported if there is a demonstrable need to facilitate development of SDS7 and any access proposals comply with the Council’s movement and highways policies;
  3. Proportionate provision or contribution toward improvements, in line with the Welwyn Hatfield Infrastructure Delivery Plan, must be made for:
    • Accessibility and movement throughout the Marshmoor Policy Area;
    • Connectivity for pedestrians and cyclists between the Marshmoor Policy Area and Welham Green Railway Station and village centre, as well as other origins and destinations in the wider area that have a demonstrable relationship with the proposal, such as other town and neighbourhood centres, local primary schools and educational establishments; and
    • Rail and bus transport accessibility of the Marshmoor Policy Area and to support wider sustainable travel initiatives, including improved bus stop facilities and support for bus services that serve the Marshmoor Policy Area.

    Heritage, Landscape, Ecology and Design

  4. A Heritage Impact Assessment may be required for development proposals, depending on their location, scale and relationship to Hatfield House and Hatfield House Historic Park and Garden. Impact Assessments should inform the siting, layout, scale and overall design of development so that substantial harm to heritage assets is avoided, any less than substantial harm is minimised, and opportunities to improve the setting of those heritage assets are implemented;
  5. Proposals will be required to adopt a high quality landscape-led approach to design, with significant planting of tree and shrub species that maintain and enhance a verdant setting across the Marshmoor Policy Area and enhance biodiversity;
  6. Proposals will be expected to retain a substantial set back of buildings from the A1000 in order to help mitigate heritage impacts and noise and air pollution;
  7. Proposals on land within close proximity to the A1000 will be required to incorporate high quality and extensive tree planting within those areas closest to the A1000 in order to help mitigate heritage impacts, improve the setting of Hatfield House Park and Garden, create and improve the general appearance of a countryside setting, and maintain the perceived separation between the Marshmoor Area and Hatfield when travelling along the A1000;
  8. The design of the main vehicular access into SDS7, boundary treatments along the northern side of Dixons Hill Road, and the scale of built development and its relationship with the Dixons Hill Road frontage should create a verdant and spacious gateway and route into and out of Welham Green that also reflects the open countryside context to the south and east of Dixons Hill Road;
  9. Building heights should be restricted to minimise heritage impacts, and in general should be lower in the eastern and far northern areas of the site;
  10. Boundaries to existing residential development are appropriately designed and landscaped to protect the amenity of those residents, particularly where the proposed development adjacent to them will be for employment uses;
  11. The siting and design of development, including the use of landscaping and buffers, should support the mitigation of air and noise pollution arising from the railway and A1000 in order to minimise the need for mechanical ventilation within buildings; and
  12. Proposals should provide appropriate protection, and where possible enhancement, of identified wildlife sites and critical environmental assets that would be affected, notably Millwards Park and the Marshmoor Lane Grassland Strip Wildlife Sites and Water End SSSI.

    Flood Risk and Drainage

  13. A more detailed understanding of flood risk associated with SDS7 will need to be established via a Flood Risk Assessment, informed by detailed hydraulic models where necessary, that takes account of all sources of flood risk, in particular fluvial flood risk from ordinary watercourses and surface water flood risk. Any Flood Risk Assessment should be informed by the Council’s latest Strategic Flood Risk Assessment Level 1 report and Level 2 assessment of the Marshmoor Area. The recommendations and guidance set out in the Level 2 assessment for the Marshmoor Area should be considered and addressed in full;
  14. The use of Sustainable Drainage Systems should be prioritised to manage surface water runoff and flood risk;
  15. A sequential approach to layout within SDS7 should be adopted so that built development is confined to Flood Zone 1 and avoids areas identified as being at high risk of surface water flooding, taking account of the vulnerability of the proposed uses and mitigation afforded by the Sustainable Drainage System;
  16. Flood risk management solutions, including Sustainable Drainage Systems, within the site should seek to reduce flood risk to third party land and the wider area wherever possible; and
  17. Necessary new utilities infrastructure, in particular upgrades to the local sewerage network, are provided.

For more information please see the Welwyn Hatfield Local Plan