The Cambridge Sustainable Housing Design Guide Emma Davies – Senior Sustainability Officer (Design and Construction)

Purpose of the Design Guide Set of design principles and baseline requirements for all new HDA schemes; Will form part of any new designer’s/ developer’s appointment, supporting and complementing the Design Brief The Cambridge Sustainable Housing Design Guide has been produced for the Greater Cambridge Housing Development Agency for new development, initially focussed on schemes in Cambridge, although a lot of what is in the guide is applicable to schemes located outside of Cambridge as well. It sets out the design principles for the delivery of high quality, sustainable new homes, the themes of Climate, Connectivity, Character, Community and Post Construction Monitoring and Maintenance. It also sets baseline requirements for schemes. So it’s a standard that is not just focussed on one aspect of what makes a dwelling sustainable but takes a more holistic approach. In terms of the status of the document, the guide will form an integral part of any new developer’s or designer’s appointment, supporting and complementing the written Design Brief provided for a particular project. It will be used for new social housing developments and wider development on Council land. It’s also our intention that the document can be made freely available to any other developer looking to deliver high quality sustainable new housing developments.

Why was it developed? Demise of Code for Sustainable Homes; Commitment to high quality design and sustainability; Links to key documents, both corporate and planning. When the Council started building in 2012/13, we were building to the Code for Sustainable Homes, with the majority of these homes being built to Level 4 of the Code, and some built to Level 5. However, with the scrapping of the Code, Councillors and colleagues in the HDA still wants to ensure that new social housing is delivered to high design and sustainability standards, in light of the principles set out in the Cambridgeshire Quality Charter for Growth. The City Council has also become the first local authority developer member of the Good Homes Alliance, whose focus is on the delivery of Good Homes that are sustainable in their broadest sense, not just delivering energy efficient homes, but which also bring about broader social and community benefits and we are also a member of the UK Green Building Council. This all forms a background to a decision to develop new guidance for the delivery of new Council housing and development on Council land, which is also identified as a key action in the Council’s new Climate Change Strategy. Some of the requirements in the Design Code also link to planning requirements set out in the emerging Cambridge Local Plan, including those for carbon reduction and water efficiency in new homes, climate change adaptation, policies related to sustainable drainage and general urban design policies. It also looks to respond to emerging issues that are currently gaining traction in housing delivery such as addressing the issue of overheating in new homes and the healthy homes movement. It’s important to stress that while the guide will make reference to planning requirements, it is not a formal planning document (such as a Supplementary Planning Document), although parts of the guide may help to inform the forthcoming update to the Council’s Sustainable Design and Construction SPD, and it has also been shared with colleagues on the Cambridgeshire Quality Panel given the links to the Quality Charter for Growth.

Objectives Address issues such as fuel and water poverty; Build homes that have a positive impact on the health and wellbeing of our residents; Build homes that are designed and built to high design and sustainability standards; Ensure new homes are easy to maintain and are adaptable, both for residents and to future climate change.

The Design Guide is structured around a set of 5 design principles The Design Guide is structured around a set of 5 design principles. Four of these were taken from the Cambridgeshire Quality Charter for Growth, known as the four c’s: community, connectivity, climate and character. These were taken as a starting point for the Design Guide, and were adapted and evolved. There is also the addition of a fifth principle, that of post construction monitoring and maintenance, which has been included as a response to the performance gap between designed and as built performance. For each design principle the design guide outlines a series of principles for the delivery of high quality, sustainable new development.

Baseline specification Within each of the 5 design principles, there are also a series of baseline requirements which new developments being delivered by the HDA will have to meet. Baseline requirements include residential space standards and accessibility standards, measures to enable the delivery of smart homes through to requirements related to carbon emissions, water consumption and climate change adaptation (covering issues such as surface water drainage and overheating). We’ve also included requirements related to minimising the performance gap through the use of assured performance tools and the need for post construction monitoring and evaluation, so we can make sure that homes are performing in the way that they were designed. For each of the baseline requirements, the guide includes details of the information that should be submitted to demonstrated compliance – much of this evidence will already be familiar to development teams as we’ve used existing requirements such as Code for Sustainable Homes, or documents that are already commonly required as part of the planning process such as Design and Access Statements or planning drawings. We’ve also not set the baseline requirements too high, so they are achievable at all scales of development (e.g. carbon requirements are equivalent to Code Level 4, which is something that we were already achieving on our new developments).

Enhancing the specification Another key part of the Design Guide is that we want teams to be inspired to innovate, taking creative approaches to delivering good homes. I was once told that local authorities had no place in delivering innovation within the housebuilding industry but I don’t believe that for a second. As part of our design guide we want to encourage enhancement of the baseline specification so we’ve come up with this idea of an enhanced specification mixing desk so that rather than design teams having to tick a whole host of boxes they can focus on specific areas where they may have developed a specialism, be that radically energy efficient homes, or the healthy homes agenda for example. They key areas where opportunities for innovation and enhancement lie are considered to be: Water efficiency and water sensitive urban design; BIM and ongoing support for residents; Healthy homes and communities; Community development; Accessible and adaptable buildings; Radically energy efficient homes; Smart homes; and Modern Methods of Construction and enabling resource efficiency – and I think there are strong links here with the Combined Authority’s plans for looking at the feasibility of offsite construction/modular housing

Benefits of the Design Guide More holistic approach as opposed to focussing on a single issue; Legacy landowners; Access to good quality housing reduces inequalities, helps people out of poverty and can reduce pressure on wider public services; Ensures that planning requirements are considered early on in the design process. We’re already seeing authorities such as Exeter, Norwich and Bristol utilising the Passivhaus standard for new affordable housing. It was something that we did consider, and it is something that could be achieved as part of enhancing the baseline specification, but there was a general consensus that for us, the focus should be more holistic looking at opportunities not just at the building scale but looking more widely at the site level. The increased focus on the role of local authorities in delivering new housing presents an opportunity for the public sector to demonstrate leadership in the delivery of sustainable housing that has a lasting positive impact on communities and for our residents. I would also argue that there is a greater role for local authorities, who as well as developing their own affordable housing, also have a role as landowners – land on which both affordable and market housing may well be delivered. We should view ourselves, to steal a phrase from Mike Roberts at HAB Housing, as legacy landowners, who have a long term interest in the development that comes forward on their land and the standard of housing that their new residents will live in. There are many benefits to taking such an approach, from reducing fuel poverty amongst out residents, helping to reduce rent arrears (Exeter has seen this with their Passivhaus schemes) and the health impacts of living in poor quality housing which helps to take some of the strain off social care and the NHS, to enhancing the amenity of local authority areas through the regeneration of areas – regeneration which should benefit all of our residents. A further benefit is that using the design guide will help to ensure that key planning requirements are considered early on in the design process, allowing for requirements to be integrated into the design of schemes, which is often more cost effective than having to deal with issues in response to comments on planning applications, which can then have an impact on the layout of schemes and also the amount of development that can be delivered on sites – surface water drainage is a prime example of this.

Any questions? emma.davies@cambridge.gov.uk www.cambridge.gov.uk/greater-cambridge-housing-development-agency