Demonstration Project

Transcription

1 Demonstration Project Cameron Close, Freshwater, Isle of Wight Southern Housing Group january 2017

2 contents cameron close 3. PROJECT OVERVIEW 4. The need to redevelop 5. catering for the demographic 6. funding, finance and variations 7. decision for passivhaus 8. delivering passivhaus 9. challenges 10. the benefits keys to success 2

3 Commissioned by Southern Housing Group, Cameron Close is a 5.07m development situated in the rural village of Freshwater, Isle of Wight. Designed by PCKO Architects and built by local contractors Stoneham Construction, this fully certified Passivhaus development comprises 28 homes and is the first of its kind constructed on the Island. All of the 28 homes were developed and made available on the affordable rent market. The 16 large family houses were released to the public as general needs rented homes. These two and three storey houses are semi-detached and arranged in pairs around a cul-de-sac, ranging from two to five bedrooms. Snapshot Value: 5.07m Client: Southern Housing Group Contractor: Stoneham Construction Architect: PCKO Architects The remaining 12 homes are one-bedroom, self-contained flats constructed for sheltered housing, targeted to the over-55 market. These homes are located in a two-storey block with pitched and flat roof areas earmarked for growing environmentally friendly sedum plants. All of the houses have front and back gardens and the flats have generous, landscaped kitchen gardens to ensure plenty of private amenity space. The varying size of the houses and the flexibility of their plan will encourage a sustainable, cohesive community. In addition, the site plan provides attractive streets and public spaces and the homes are carefully orientated to provide a feeling of security whilst maintaining privacy. 3 Planning permission was sought based on the flats being general needs to maintain flexibility. The project underwent an extensive programme of demolition, including rehousing existing residents. Construction took place between September 2013 and August 2015.

4 The Need to Redevelop The site, including the original sheltered housing scheme called Ainsworth Court was part of a stock transfer from the South Wight Borough Council to the now defunct South Wight Housing Association in Southern Housing Group became the owner of the site when the Group merged with South Wight Housing Association in As the Council undertook a review of services for older people on the Island, it identified Ainsworth Court as a high-risk scheme in need of remodelling to meet local strategic priorities and the Decent Homes Standard. The Group had also noticed that the scheme s occupancy level was lower than normal and received feedback from applicants saying that Ainsworth Court did not meet their expectations. Southern Housing Group s Care and Supporting Independence Team started to hold regular liaison meetings with residents and, as the project progressed, the Group s Development Team joined these meetings. The final decision was to redevelop and rehouse the existing residents in Southern Housing Group s new dedicated sheltered scheme elsewhere in the village, Whitmore Court, or in other homes that would best suit their needs, whilst accommodating new residents in the Passivhaus development. The previous site, Ainsworth Court 4

5 Catering for the Demographic The need for a mixed tenure housing development is not as prevalent on the Isle of Wight as it would be in London and the South East. The decision to implement a single tenure offering was two-fold. The prim ary reasons were a defined difference in the demographic and demand for housing on the Isle of Wight where the average age is 44.4 years, compared to 34.0 in London. In addition, a very high proportion of people on the Island own their homes outright, reflecting the high proportion of retired people who have paid off their mortgages. Only around 30% of people (60,000) continue to rent on the Island, indicating a much less competitive market. Using knowledge and research of the area, PCKO Architects designed the self-contained flats to ensure that the Resident Services Officer, who is based at the nearby complex at Whitmore Court, can provide low-level housing support effectively. The internal design also incorporates bespoke features to improve accessibility for residents including a warden call and door access system, proximity access system and CCTV system in every home plus a communal Stannah platform lift accompanying the staircase. The flats also provide flexible accommodation with the ability to divide the living space to provide a temporary second bedroom. The 16 houses range from twobedroom, four-person homes to fivebedroom, eight-person homes, which are all available under the Affordable Rent Model (ARM) to cater for a range of income levels, age groups and families, creating a cohesive homegrown community at Cameron Close. 5

6 Funding, Finance AND Variations Andrew Hulmes, Area Development Manager at Southern Housing Group, stated, During the tendering process, we requested that contractors identify and estimate the extra costs of building to the Passivhaus standard rather than simply to the outgoing Code for Sustainable Homes - Level 3. At the time, there was an estimated additional capital cost of about 7%, or about 10,000 per home. This meant that capital costs were going to be higher from the outset, however the high-quality of these sustainable homes and benefits for residents would justify the extra cost incurred for this innovative scheme. Southern Housing Group set out to seek funding, undergoing a bidding procedure to receive 1.5m in grants from the Homes and Communities Agency s (HCA) Affordable Homes Programme , ensuring the viability of the Passivhaus scheme. Grants arrived in two phases: 50% at the start of the works on site and 50% at practical completion of the scheme. The Group also secured additional funding from the Isle of Wight Council and the Regeneration Capital Grant Fund. This financial collaboration between parties facilitated the possibility of bringing an innovative and sustainable development to the Island. "The IOW Council fully supported the approach." Andrew Hulmes added, We presented our plans to build Passivhaus homes to the Isle of Wight Council and they fully supported the approach. They delivered funding to cover the additional costs of bringing the homes to the Passivhaus standard. The proposition of building Cameron Close to Passivhaus specification was in line with the Isle of Wight Council's sustainable development strategy, 'Eco Island', as part of their mission to become the UK's most sustainable local authority by

7 Decision for Passivhaus After a process of delineating initial proposals and following-up with visits to a number of existing projects, both completed and on-site, came the approval to make Cameron Close a Passivhaus development. Southern Housing Group felt that the Passivhaus approach was the best suited to meet the Group s sustainability objectives of delivering affordable warmth and creating a low carbon organisation, without the need to provide potentially expensive to maintain renewable technology solutions. What particularly appealed to Southern Housing Group was Passivhaus fabric first approach to developing homes, which is associated with build methods required to achieve long-term low energy use and deliver high quality homes. Adopting a fabric first approach involves maximising the performance of components and materials that make up the building fabric itself, before considering the addition of mechanical or electrical systems. This can help reduce capital and operational costs, improve energy efficiency and reduce carbon emissions. A fabric first approach can also reduce the amount of maintenance during a building s life. The core principle of the Passivhaus standard is to reduce the requirement for space heating and cooling, whilst also creating an excellent indoor comfort level. This is achieved by specifying high levels of insulation, exceptional levels of air tightness, and the use of whole house mechanical ventilation heat recovery system (MVHR). A Passivhaus is a building for which thermal comfort can be achieved solely by post-heating or post-cooling of the fresh air mass, which is required to achieve sufficient indoor air quality conditions without the need for additional recirculation of air. Through the use of materials and build methods, the Passivhaus standard reduces the heating requirement to the level where a traditional heating system is no longer essential. Cooling is also minimised by the same principles, through the use of shading and in some cases via the pre-cooling of the air supply. Night purging and the use of natural cross-ventilation through open windows is encouraged during warmer months. 7 In order to achieve Passivhaus certification, each home needed to meet stringent and sustainable readings for heat dissipation and ventilation. Practically, this necessitated the installation of 500mm thick walls, triple glazed windows, whole house mechanical ventilation with heat recovery and low capacity condensing boilers to provide hot water and minimal top up space heating. In addition, using pre-certified fixtures and fittings ensured that minimal heating and primary energy limits were met.

8 8 Delivering passivhaus Southern Housing Group commissioned WARM, an independent consultancy and accredited Passivhaus building certifier, to assist them throughout the Passivhaus process. WARM's Duties o Inputting into Cameron Close s brief and concept. o Providing Initial and detailed design advice. o Assisting with planning submission. o Providing access to a supply chain of Passivhaus certified components and approved suppliers, essential to achieve certification and key for the successful delivery of Cameron Close. o Supervising the site, including organising visits to monitor progress and ensure that Passivhaus standards were met. o Carrying out the certification process with the Passivhaus Institute on Southern Housing Group s behalf. pitched roofs contain 600mm of insulation in the lofted areas. The project s source of innovation stemmed from the performance of the materials combined with a modern architectural design. By selecting certified components from the outset, there was more certainty that energy, heating, and air tightness criteria would be met, therefore minimising additional costs for certification. For example, design specifics included pitched roofs of a slate tile finish with a considerable amount of insulation in the lofted areas with 600mm insulation in the lofts from a certified supplier, in this case Rockwool. Flat roofs incorporate 250mm of rigid PIR insulation and windows were Passivhaus certified triple glazed units with a heat insulation effectiveness (Uvalue) rating of 0.78W/m2K.

9 CHALLENGES Andrew Hulmes noted, We [Southern Housing Group] were determined to build a high quality and environmentally friendly development that would benefit our residents and the local community. We believe that overall the delivery of Cameron Close was a success, particularly as this was the first time we built a fully Passivhaus certified scheme. The main challenge revolved around the meticulous attention to detail needed to achieve the Passivhaus standard. Southern Housing GRoup's collaboration in action o Make sure that Stoneham Construction were on board at the very beginning of the process of developing the Group s first Passivhaus scheme. o Ensure that Stoneham Construction could develop processes and appropriately train their staff to build to Passivhaus standards. o Get hold of the necessary materials as the UK market for Passivhaus is still in its early development stages. Early engagement with Stoneham Construction and subcontractors ensured that the necessary arrangements were in order to meet the project s delivery programme. The Passivhaus scheme provided great learning opportunities in design and construction for the Group and their contractors, both with a stake in learning new methods and industry practices, including the possibility to explore how this, or part of this, fabric first approach could be replicated in future schemes. Southern Housing Group s Head of Sustainability, Will Routh, stated, They [Stoneham Construction] developed processes and training for their staff to the high standards of construction delivery. I think because we had discussions right at the start of the contract, we all knew what was needed, which helped smooth the processes going forwards. Animal conservation caused delays to the programme in the demolition phase following the discovery of bats in one of the loft spaces and a small badger set in the garden. In accordance with the bat license requirements, the project team conducted a series of bat surveys over the summer, which led to the construction of a new habitat space, formed in the loft of a neighbouring block, ahead of the next spring when bats come out of hibernation. The team also monitored the badger set over several months and, as expected, the badger eventually moved elsewhere meaning that the set could be removed. Southern Housing Group also extended the contract period to accommodate the additional time needed to achieve the necessary high attention to detail required meeting and maintaining airtightness requirements. 9 The final handover of the scheme took place in August 2015, with the construction of the homes completed a few months before. The delay in the handover was due to an issue between the Isle of Wight Council s Highways Department and Southern Water over the location of a water main and the specification of the future highway preventing the road from being completed and hence access to Cameron Close for residents.

10 the benefits Southern Housing Group has been working for more than 10 years towards reducing its impact on the environment and opting for a Passivhaus scheme was a decision that delivers direct benefits to the residents. Cameron Close was an opportunity to consider the feasibility of demolition/construction or retrofitting stock in a bid to improve the properties that have the lowest Energy Performance Certificate (EPC) energy ratings and therefore the highest electricity and fuel costs. The results of the first six-monthly occupancy report showed that bar a couple of exceptions, the houses and flats at Cameron Close met the Passivhaus performance targets for heating and hot water. Ambient temperatures in the winter period and relative humidity were both within satisfactory ranges; in addition, residents were very satisfied with the warmth and comfort level of their homes in winter, with a number of households not switching the heating on at all. Residents also have significantly lower bills with average annual outgoings for both flats and houses currently estimated at 75 and 225 respectively. The Group estimates that for the entire development, the annual saving on energy costs will be around 25,000. In turn, this should help residents to better manage their money and lower the level of rent arrears for the Group. Residents will also enjoy cost savings through Southern Housing Group s dedicated Home Energy Advice Team (HEAT). Established in 2014, HEAT provides face-to-face energy advice to residents, helping over 700 residents save a total of 160,000 off energy, gas, and water bills, an average of 230 per household. HEAT delivered advice on improving performance and reducing utility bills for residents at Cameron Close by demonstrating the benefits on effective use of the towel rail and the mechanical ventilation system. 10 The Group currently estimates that energy use at Cameron Close will be 45% lower than a house built to Code for Sustainable Homes - Level 3; based on current gas and electricity tariffs, this translates into a significant reduction in energy use and into to a financial saving of approximately 900 per annum for a three bed house of 86m2.