This pilot case study sought to explore the National Model Design Code (NMDC), focusing on the design code process for a site in fragmented ownership to the east of the existing New Town centre. Key themes included the approach to developing a vision from community engagement input; a digital engagement approach, supplemented with internal officer and member workshops and in-person engagement events; and using design code parameters to support the transition of a town centre site from low density industrial to a high density urban mixed use neighbourhood whilst working collaboratively with landowners to bring forward a comprehensive development.
Context: Town Centre
Focus: Producing a character led design code for strategic site
Project team: Dacorum Borough Council; Tibbalds
Region: South East
Dacorum is situated in South West Hertfordshire. It includes the towns of Hemel Hempstead, Berkhamstead and Tring, and a number of villages. Through the production of the draft local plan, suitable allocations for development were identified to meet housing, infrastructure and other needs to 2038. To bring these sites forward, design codes and masterplans will be used in a collaborative process between the local communities, landowners, the local authority and other stakeholders. Dacorum is seeking to utilise design codes from an early stage in the development of these projects.
Hemel Hempstead town centre comprises two main areas: the Old Town in the north, and the New Town in the south. The Paradise site is located to the east of the New Town core and is within the larger town centre boundary. It sits to the north of St Albans Road, a major arterial route into the town; however; due to its location, it lacks presence within the town and is not necessarily a place that residents or visitors would happen across without a specific reason. The site area is 2.92ha, and it is currently allocated for residential units, employment generating uses, a replacement food bank, and public open space. It is currently occupied by a mix of local employment and residential buildings, all of which benefit from the transport links and proximity to the inner core of the New Town centre.
The site is in fragmented land ownership and to address this complexity, ownerships and already proposed schemes were first mapped to inform the assumptions underpinning the framework and design code.
"Can we deliver a high-density housing allocation site with
design features that are locally popular"
A key objective of the design code pilot was to bring the community and council members on board supporting intensification and growth in the town centre, by showing how design codes can enhance place, character and design quality. The methodology and process set out for this pilot could be rolled out across other areas within Dacorum such as the Two Waters Masterplan and other growth allocations. The design aspiration is to create a compact development on the site that signals the approach to the town centre from the east. This site could create a benchmark for new, sustainable development that has strong links to Hemel Hempstead’s New Town heritage and serves its local community. The code will assist with transitioning the site area type which is at present Low Density Industrial to a High Density Urban Mixed Use Neighbourhood.
The three objectives for the design code pilot were:
1. Encouraging Sustainable Growth
The design code would provide clarity for landowners and developers, encouraging and streamlining investment in Hemel Town Centre. An early aspiration of the Dacorum pilot case study was to develop a standard coding process with templates that could be reproduced across different sites; however; because of the distinctive nature of the site, a decision was taken early on not to pursue the use of templates in this case
2. Design Codes as a tool for Development Management (DM)
Being graphically clear with easy to use spatial and numerical data was paramount. In addition, developing a tool that could be used in pre-application discussions, and digital platforms for use by development management officers were also key objectives.
3. Digital Planning
Through the design code pilot programme, there was the opportunity to explore digital tools in planning such as Commonplace and ESRI (Environmental Systems Research Institute, a provider of GIS software, and spatial mapping analysis).
"The design code cannot force change, but it can be flexible to allow for future changes"
Dacorum Borough Council appointed Tibbalds Planning and Urban Design to produce the design code. The most innovative aspects of the coding process developed out of the restricted timetable and resources for the pilot. The site is an industrial estate, comprising a number of sites in fragmented ownership with little strategic design work undertaken to date. These aspects - in addition to the short six month timeframe for the project - dictated the final outputs. Consequently, the final design code was a high-level code providing strategic coding with focussed detailed guidance on aspects such as appearance and character structured around three key coding categories, initially comprising Built Form and Identity, which were later extended to also include Movement and Use.
As there was no existing vision (masterplan) in place, community engagement was used to underpin a new spatial vision for the area, which then led to the development of a regulating plan, in place of a detailed masterplan.
The regulating plan sets out the framework for the development and establishes the urban design principles for the site, by which schemes will be evaluated, notably:
• Streets and blocks
• Key nodes
• Continuous active frontages
• Secondary and sensitive frontages
• Marker buildings
The engagement process was a significant part of the pilot project approach, and enabled identification of local preferences for design characteristics, which informed the vision, regulating plan and design codes. Traditional engagement approaches have previously elicited a very low response rate from existing businesses and residents on the site. The focus area for engagement was extended to include the wider Hemel Hempstead Town centre to provide a characterisation evidence base for future design and placemaking projects.
The strategy explored digital options for community engagement using Commonplace as the digital engagement platform, with the aim of extending the public ‘reach’ of the consultation, while developing a greater understanding of what people liked, and what they didn’t like, in addition to asking specific questions that would feed into the new vision for the Paradise industrial estate. There was also a series of in person events such as a youth workshop on design codes and walking groups in the town centre.
The Engagement report covers the results gathered from the Commonplace website which launched on 30 June 2021. In total, there had been 187 respondents (80% of whom live within the Hemel Hempstead postcode area) who made 480 contributions. Final outputs included the Commonplace Engagement website. https://yourhemelhempstead.commonplace.is/ and a report to steer future strategic and character led design in the town centre. Notably the pilot allowed an exploration into how design codes can draw on a current interpretation of Hemel Hempstead’s legacy as a Mark 1 New Town.
The design code was prepared with the needs of both developer teams and planning officers in mind, so that it is practical and sets out clear justifications and requirements.
All design guidance chapters are laid out on the page in a similar format with a reference box on the right-hand side. A compliance worksheet in being produced which can provide an interactive tool during the pre-application process to monitor compliance in the emerging design. This provides the key information that the chapter relates to, e.g. design priority, engagement topic and other areas of the design code that are cross-referenced. The design code focused on the most appropriate NMDC characteristics for the site and the strategic nature of the code: Built Form, Identity, Movement and Use. There were also three priorities identified in the code: Integrated Neighbourhoods, Urban Community, and Sustainable and Green, which were established as part of the engagement process. These are related to Hemel Garden Communities Spatial Vision and are signposted by icons throughout the code.
Each section is specific in terms of detailed design with principles being accompanied by building typologies to structure the codes, each linked back to the regulating plan. In time the aspiration is for the design code to be adopted as a Supplementary Planning Document (SPD), so that it will be a material consideration with significant weight.
"If you are doing your design code in a ‘town centre’ area rather than a green field site,
your vision can be challenging because you are going to have to take the existing community with you on that journey"
Time, skills and resources – Substantial time, skills and resources are involved. There may not be sufficient in-house urban design or design coding expertise within local authorities, and this needs to be resourced, either internally or with consultants. Getting different stakeholders to ‘buy-in’ to the process will always require time, to enable a wider understanding of what a design code is, and what the key principles mean.
Viability input for town centre sites – Viability is a major issue, particularly in terms of proposed uses. Viability input is needed to test elements of coding versus elements of guidance; and Dacorum believed that it was only viability tested elements of projects that could be mandatorily coded, notably on heights, quantum, uses, and parking.
Engagement – A key focus of the engagement was obtaining input on what is locally popular. While identifying design preferences was challenging due to a lack of community response to the engagement events, there was a good response from the in-house workshops where some themes were developed that fed directly into the design code. Digital engagement on locally popular design characteristics was also particularly successful and played a key role in informing and underpinning the vision for the Paradise area. Overcoming the challenges of establishing what is provably popular in town centre locations requires a sustained and fundamental engagement with local populations.
Delivering local character – The pilot highlighted the need for a strong characterisation analysis and vision evidence-base as a foundation for the design code and to inform guidance on appearance, materials and character. The strong community engagement strategy fed into – and significantly informed – this process. Town centre sites may exhibit more variables and greater market dependency, while design quality can be harder to characterise particularly in areas of lower quality townscape.
Delivering a new ‘piece’ of town centre – The pilot demonstrated a comprehensive and sensitive approach to balancing a coherent design-led vision with the fractured ownership of the existing place to deliver a piece of town centre. Key elements of the vision and regulatory plan included introducing mixed uses, a strong and connective public realm, and links to the open space network and future development areas to the north.
In-depth design process – The masterplanning section within the NMDC is at a high level, specifying overarching principles including movement networks through the site. There is, understandably, a gap between these overarching principles and the level of detail required by the code, for example window and façade treatment. To meaningfully code these details, a more in-depth design process needs to be undertaken to identify the character of the new place being created. The extensive digital
engagement undertaken at Dacorum sought to tease out what was provably popular and was a key driver of this design process, identifying which aspects of the town centre character were important, both in the New Town and Old Town areas.
As part of the NMDC pilot project research, interviews were undertaken with key stakeholders involved in each of the pilots. This section summarises some of those reflections.
Clear local leadership, bringing stakeholders together
We were fortunate having strong place making leadership because if you don’t have the support of your Chief Executive, Director and Assistant Director on this - and if you are doing this against the tide – then it would be much more difficult. Knowing that you do have that support instils a lot of confidence that this design code work also fits into the bigger effort to improve design quality borough-wide.
Sending a clear message about design quality and design coding expectations
It is important to be clear about the design and placemaking aspirations for the code and where this will be most impactful. This is linked to the size of the site, viability, and appreciating the specific strengths of design codes. Additionally, doing a design code ad hoc in the middle of a plan making area has been really challenging because it can be difficult to pin the vision down from a viability point of view. It’s important to understand the mix of uses from the start whilst developing a mixed use neighbourhood particularly with regard to vertical zoning. The location of commercial and residential in particular needs to be carefully considered in order to provide appealing environments for both living and working to the future community.
A design code for an occupied site, as opposed to a green field site, is very different
To take an existing site with occupiers you have to be very clear what your vision is, as this may please some people while others may be less happy with aspects of the vision.
In reality, an existing site with occupiers requires a stronger collaborative approach to develop the vision.
Time, skills and resources
Understanding urban design and letting people know what this is going to mean is important, so getting buy-in and translating the design code into plain English for colleagues, members and the community is very important. At the moment, in managing planning teams, we are not geared up to have this level of urban design expertise in-house and this level of design coding delivery. We did quite a detailed study as part of the pilot, mapping out project hours and costs. This was helpful in informing our future resource requirements whilst putting together design programmes in other areas in the Borough such as South Hemel and understanding elements of coding that we can deliver ourselves in-house through upskilling within the team. It highlights the need for more design resource for this type of work going forward.
Allowing adequate time to interview a number of consultants and maintaining an active role in the production of the design code throughout the development process is incredibly helpful to ensure the code meets the needs of the Development Managers (in particular) who will be using the code.
Understanding viability at the start of the process
In the discussions we have had with our consultants, we have come to realise that there is the need to not over-constrain what we are doing. There is such a difference doing a design code with an outline masterplan by a developer; there you can be a lot more specific about the elements of the code because you have greater certainty with regards to the brief and quantum of development. Viability is an important issue, particularly with regard to the uses. Viability input is also needed to test elements of coding versus elements of guidance as it is likely that only viability tested elements of projects could be mandatorily coded. The key things that viability controls are the heights, quantum, uses, and parking which is the standard viability format, so for us it is those key parameters that impact the code.
"With the materials and appearance sections in our code, we are just being a bit looser with the language
and guidance offered, only being strict on certain elements such as the use of brick or masonry"
Local character – evidence base through analysis and engagement
The pilot has highlighted the need, at the outset, for a strong characterisation analysis and vision evidence base as a foundation for the design code, providing guidance on appearance, materials and character. Hemel Hempstead has two town centre character areas – the Old Town and the New Town centre and defining a design language through coding and engagement that can respond to the character in both of these areas has been a key part of this programme. Defining townscape and the character of the area surrounding the site underpins the decisions on what to code.