Case Study: Othello Way

Baca Architects has completed construction of Othello Way, their latest residential project located near the historic heart of Stratford-Upon-Avon, Warwickshire. The project comprises of 11 high-quality homes located within a flood plain, designated by the Environment Agency (EA), as Flood Zones 2 and 3 has regenerated a brownfield flood-risk site that has lay dormant for over a decade.  It is the first of its kind in the UK and importantly has demonstrated the deliverability of new flood mitigation and resilience measures.

Stratford upon Avon District Council’s Local Plan requires the construction of new 3,500 homes by 2031 but suffers from a lack of suitable sites and/or willing developers.  The proposal regenerates a brownfield site which was occupied by a derelict three storey 1970s apartment block at risk of both surface water and fluvial flooding. The existing apartment block had almost a third of its bed paces at ground floor.  The Client had an aspiration for a group of quality homes in this attractive location connected to nature and close to the centre of the town. Building in the flood plain in this location required that homes be raised to a safe level above potential flood water. Additionally, developments within flood plains should allow space for flood water to flow within the site in a controlled and planned manner, improving conditions of ground water permeability from their current state.

To be compliant with the Environment Agency’s guidance, primary floor levels would be required to be approximately 1.6m higher than the adjacent ground level. During the consultation period, the Local Parish Council indicated that they supported the scheme but did not like the raised floor level and sought direction local planning authority as to whether they could condition a lower level. The Local Authority sided with the EA. This is an important stance as the raising floor levels means that the ridge heights of the streetscape will rise as new development replace old.

The design evolved to meet these demanding criteria. A gently ramped road access from the middle of the site to the raised levels of the houses, and an elevated pedestrian and cycle path to the west, provide a through route across the site and a safe- haven in flood events. To alleviate the Parish Council’s concerns of noticeable change in ridge heights the design steps the building massing down at the extremity of the site. The houses are built on raised piles with a floodable zone below, guarded from debris by louvered screens. The green space remaining is landscaped as rain gardens and swales to help retain and control water run-off.

The dwellings are arranged as a mix of detached and terraced townhouses, all planned within a shared communal garden and amenity space. The site plan is compact but fees generous in nature. The combination of both building layout and internal planning means overlooking is mitigated and yield a sufficient quantum of development to pay for flood measures. The site’s internal road connects to the highway at grade before gently rising to circa 1.6m at its highest point.

The redevelopment of the site will see no bed spaces provided at ground floor and all the principal floors are elevated to be above the Environment Agency’s 100-year plus 20% allowance for climate change. Space is made for water across the site through a number of complementary strategies. Dwellings are elevated on stilts with their voids protected by permeable “flood trims” around their perimeter. Steps and amenity terraces that make up the level changes between the ground and habitable floor levels are also permeable to encourage flow of floodwater.

These combined interventions mean that the total site footprint is floodable, providing flood storage locally and relieving flood pressure to neighbouring sites. This model is important as it demonstrates that new housing can be build in urban areas safely, without the need to expand into the greenbelt; and can relieve flood pressure on existing neighbouring sites.

Baca Founder and RIBA Fellow, Richard Coutts sits on Defra’s Flood and Coastal Erosion advisory group and developed the design with policy foresight in mind. As such the design is one of the first capable of becoming an adopted sewer as it not only utilises a SUD system, as is typically used in an attempt to attenuate water flow, but the majority of the site is considered for flood storage making it more effective, with a largely increased capacity for water. Rainwater collected from the roofs is drained and stored separately from space made for fluvial (river) flooding.

Baca’s policy research for Government and through the RIBA has meant the practice have been able to feedback to Defra the issues of conflicting policies. In this case the EA’s safety policies prevailed.

This combination of adopting both blue and green infrastructure, aptly named “turquoise infrastructure”, also has benefits for utility companies as it provides with increased revenue streams (grounds maintenance costs can be included in service charge bills), increased flood attenuation across catchment areas and also doubles as a natural filtration system helping the utility companies clean the water before it makes its way into the foul drainage system. Whilst the utility company for this site is Severn Trent, Yorkshire Water are also working with baca to utilize a similar model for their flood risk sites.

Commenting on the proposal, Richard Coutts, Principal of Baca Architects, says:

“As climate change increases the likelihood of flooding and major storms, we need to better understand how to design for flood risk. 

Potentially more influential than our Amphibious House, the “Othello Way” flood resilient housing, combined flood protection measures and landscape solution offers proof of concept to a much wider audience – showcasing an attractive place to live and a finically attractive solution. The design is deliberately low-tech and could be easily adopted by mass house builders. There were conflicts within the planning system and we have passed these recommendations to Defra to smooth the pathway for others”

“This is a clear strategy to unlock those brownfield sites located within floodplains or next to rivers to provide homes at the heart of city centres,” he says. “It’s good sustainable development in terms of transport and locating people where the jobs are, but it’s also another way of resisting urban sprawl into the green belt.”

Client quote (Holloway Properties):

 “We approached Baca Architects to help us unlock a brownfield site that was at flood risk on the main road into Stratford upon Avon. Several developers before us had tried and failed and we thought that with Baca’s expertise they could help us find a solution. It was essential that we worked with an architect who had vast experience of working with water and sensitive sites. Baca appealed to us for both their knowledge and innovation. Over a period of many months and patience, the team were able to work with the local authority and Environment Agency to develop proposals for 11 new home high quality flood proof homes.”

BRE Quote:

BRE’s Kelly recommends, “new developments should not only reflect the immediate risk but demonstrate creative solutions that mitigate the effects of climate change”.

'A pioneering flood resilient scheme with turquoise infrastructure and sustainable’ urban drainage.'