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Sustainable heating solution

Dachs mini-CHP from Baxi-SenerTec UK, part of Baxi Commercial Division, has been identified by Dundee City Council as a consistently cost-effective element of its drive to achieve energy efficiency.

Dundee is creating a sustainable energy infrastructure for the long-term. The City Council has trialled different renewable and low carbon alternative heating technologies and the Dachs mini-CHP combined heat and power solution is being variously deployed in the city, reducing carbon emissions and improving the energy efficiency of buildings of diverse use.

The Dachs mini-CHP solution is designed to run continuously in buildings with a large heat load and almost continuous operation. For example, in Brington Place, a home for elderly residents where the heat load was being met by three condensing boilers, the operation of a Dachs mini-CHP greatly reduced the call on the boilers to supply the heat load, while generating electrical power to meet the power load.

The CHP unit, running almost continuously, has delivered 66,000 kWh of electricity and 160,000 kWh of heating since being commissioned. Based on previous bills for electricity from the grid, the savings for the council run home amount to almost £2,500 per annum. These savings do not take into account the benefits that will be derived from the extended operating life of the boilers due to greatly reduced use, the consequential reduced maintenance costs and the reduced carbon emissions.

The cost-effectiveness of CHP has been confirmed by its use in the plantroom serving the council-run library, theatre and office areas in the Wellgate Shopping Centre in the heart of the city. Two Dachs mini-CHP units were deployed to support six boilers that were already in place to meet the heat load.

In an 11-month period following installation, the two units ran for more than 5,500 hours, generating almost 69,000 kWh of electricity and well over 100,000 kWh of heating. The dramatic reduction in boiler workload and the considerable lessening of the grid-supplied power demand, together led to a saving of over £4,000 in running costs. In addition, the two units have jointly avoided nearly 24,000 kg of carbon emissions.


Protection and sustainability balanced

The Netherlands Institute for Ecology is now housed in a purpose-built timber and glass building designed to the highest standards of sustainability, and Arch Timber Protection’s fire retardants are safely protecting the building and staff at the site.

Timber is a crucial and significant element in the new building and thermally-modified Plato Wood, produced from sustainable spruce, has been used for external beams and cladding. These components are protected using Arch’s NON-COM exterior, a polymer-based fire retardant to provide a proven and highly effective surface spread of flame protection. Interior Plato Wood spruce timbers used in the public areas of the building are also fire retardant-protected with Arch’s Dricon, a water-based fire retardant treatment. The timber and the Dricon treatment have been supplied by Foreco Dalfsen.

The timbers for NON-COM Exterior protection had to be accurately produced and then carefully shipped in segments to the UK, treated by Arch and then shipped back to the site for construction.

Arch Timber Protection BV general manager, Arno van Oosten, said: “NON-COM Exterior is the only leach resistant fire retardant pressure treatment available on the European market. This added an extra step to the building process because everything had to be mapped out in great detail and prepared before it could be sent over for treatment by Arch in the UK. However, we were able to work directly with the timber supplier and builder and make sure that all the steps were as cost-effective as possible.”

Claus & Kaan Architects designed the building according to the cradle-to-cradle (C2C) ecologically-sound building concept.

Environmental impact minimised

Balfour Beatty Engineering Services (BBES), is set to begin a £3.5 million mechanical and electrical (M&E) services contract for the new £9 million Beatson Translational Research Centre (TRC) in Glasgow.

Being constructed by Mansell, a Balfour Beatty Company, for the University of Glasgow, the project will see the creation of the new four-storey research laboratory, office building and car parking facilities.

The project’s M&E services have been designed by mechanical and electrical building services engineers, KJ Tait. The M&E services which are being delivered by Mansell, incorporate a number of sustainable elements including high efficiency turbo chiller and air handling units with Econet heat recovery packages. To further minimise the environmental impact of the project, BBES has incorporated offsite manufacturing for the modular risers and the plant room.

Using the latest lean construction methods and off-site manufacturing techniques, BBES will prefabricate the modular risers and plant skids, before delivering to site ready for a faster, more efficient and safer installation. Manufactured by BBES at its Modular Systems + facility, this will allow site construction to run concurrently with manufacturing. As well as reducing working hours on site, including hot works and working at height, this approach will also reduce material waste while ensuring quality control through manufacture in a controlled environment.

Other M&E services that BBES will supply and install on site comprise full air conditioning, BMS controls, fume and MSC exhaust systems, RO water, medical gas systems, UPS and generator standby systems, small power and lighting systems.

The project further demonstrates BBES’ commitment to delivering sustainable projects in terms of efficient and low environmental impact delivery as well as the creation of low energy in use buildings.

Work on the Beatson Translational Research Centre is expected to be complete in summer 2012.

Work of art

For the largest purpose built exhibition space outside of London and one that is literally built into a river, the stunning new gallery, The Hepworth Wakefield, is a work of art.

With its prominent site at the head of the fast flowing River Calder, this modern building pushes the tolerances of architectural design. To protect against the external environment, including cold transfer from the river, and create the perfect internal environment for visitors to the gallery, high performance insulation was required. PIR manufacturer Celotex demonstrated it had a range of solutions that would provide the thermal performance the gallery required.

Designed by award winning architect David Chipperfield and built by main contractor Laing O’Rourke, the 5,000m² gallery will play a vital role in the redevelopment of the Wakefield Waterfront. The two-storey building is formed from a conglomeration of 10 individually sized trapezoidal shaped blocks, responding to the scale and rooflines of the surrounding small scale industrial buildings.

The steel framed concrete building has been designed to withstand the impact of a fast flowing river and as such the walls had to be reinforced to almost reservoir standard. The gallery walls float 30 millimetres above the floor, so hidden supports had to be constructed to support the magnesite floor.

For a project where it was essential to protect the structure from the elements particularly the cold river water and fluctuating water levels, subcontractor Crown House installed 2,300m² of 75mm thick GA4000 as lining for the concrete walls and 1,800m² of 50mm-thick Celotex FF4000 as high performance thermal insulation for the underfloor heating system.

Made from PIR (polyisocyanurate) with foil facers for improved emissivity, Celotex GA4000 and FF4000 both achieve an excellent lambda of 0.022W/mK, and have a confirmed low environmental impact through its BRE Approved Environmental Profile. Celotex GA4000 has also been awarded an A+ rating when compared to the BRE Green Guide 2008.

When it came to floor insulation, 50mm thick Celotex FF4000 was laid on the structural base then covered in poured concrete. Designed for use in internal underfloor heating applications, Celotex FF4000 is available in a broad range of thicknesses from 50mm to 125mm and in a board size of 1200mm x 2400mm.

The 75mm-thick Celotex GA4000 was used in the cavity walls of the steel-framed building – fitted between the external concrete walls and internal block walls. These durable and extremely lightweight boards, available in a range of thicknesses from 50mm to 100mm and a standard board size of 1,200mm x 2400mm, are easy to cut to fit using hand tools making them ideal for a speedy application.


Economical solution

Glazing elements by Kawneer have helped the first phase of the redevelopment of the city centre campus of the University of Wales Newport achieve a BREAAM ‘Excellent’ rating.

Kawneer’s AA100 curtain walling, AA601 top-hung casement windows, and AA605 low/medium duty swing doors and series 190 heavy-duty commercial entrance doors, which feature on all elevations of the striking building, have also helped BDP architects achieve the design objective of it being open and transparent to the community.

The £35 million building on the banks of the River Usk, next to the city’s new landmark footbridge, houses the University’s Faculty of Arts and Business. This creates a magnet for cultural activity along the riverfront as well as a centre for enterprise that embraces a contemporary arts centre, extensive exhibition space and a national photographic archive.

A collaboration between the university, city council and Newport Unlimited, the urban regeneration company for the city, the new campus is part of a major redevelopment of Newport’s city centre.

The glazed elements were installed by approved specialist contractor AB Glass for main contractor Willmott Dixon Construction who specified Kawneer systems with secondary steelwork to achieve the required spans (typically 10.5m at ground floor and up to 17m at first floor).

A BDP senior architect said this combination was in preference to a steel curtain wall system as it was the “most economical solution”.

She said: “Until working on Newport, the design team had thought that a steel curtain walling system would be the most economical solution for large spans as it negates the need for secondary steelwork. But current market trends are proving that aluminium and secondary steelwork is just as competitive and a solution favoured by contractors so will probably be specified more and more very early in the design.

“As the concept of the building was to be transparent and open we wanted to retain as much curtain walling as possible and the Kawneer systems have certainly complied with the aesthetic requirements of the project. We had to use a high acoustic and solar performance for the glass as the building is on a very exposed, tight urban site next to a busy road.”

The Kawneer systems interface with brick, zinc and timber soffit. In semi-circular floating pods suspended from the first floor slab at the front of the building, much attention was paid to the isolation of these structures and the curtain walling to minimise movement on the latter.

And at roof level, the glazing disappears above the timber soffit to give the effect of the curved roof floating over the building. By extending the curtain walling in this way and concealing it, BDP was able to step the top transoms to follow the roof line rather than having it curved if it was exposed.

The university’s director of facilities management, Stephen Godber, said: “During the entire design and construction of the City Campus we sought a high-quality design and fittings at an affordable cost for the university as a public sector body. We are delighted with the final project as a whole and the choice of suppliers by BDP and Willmott Dixon.”


Edwardian to efficiency

A solid brick, Edwardian terraced house in Balham has been transformed into a model of 21st Century energy efficiency.

The project (funded through the Technology Strategy Board’s ‘Retrofit for the Future’ competition, a programme to kick-start retrofitting of the UK’s social housing stock), aimed to refurbish the property to near Passivhaus standards, while causing as little impact to the aesthetics of the building as possible.

Social housing provider, Family Mosaic, the owner of the property, engaged architects, Prewett Bizley, for the job. Prewett Bizley is a member of the Passivhaus Trust and the company’s project designer, Robert Prewett, is a Certified Passive House Designer.

Robert said: “We took a very low carbon approach and the ambition was to reduce heating energy requirement, which is usually the biggest use for houses in this country. The plan was to create a highly insulated and air tight house. We set very ambitious targets for this refit and we worked very hard, building on past experience, to make sure we got the performance levels we needed.”

Energy performance targets for the programme were based on an 80% reduction in CO2 emissions from a baseline of 97kg CO2/m².yr (typical of a 1990s 80m² semi-detached house). Achieving such rigorous standards called for the internal fabric of the property to be stripped back, to identify and tackle potential air leakage problems. Then a continuous air tight, high performance internal thermal envelope was constructed – the key to the refurbishment’s excellent energy efficiency, according to Robert Prewett.

He added: “If it is to work, the internal lining must be continuous, otherwise it’s like wearing a jersey with holes in it – heat just escapes. You need excellent insulation and it must be very air tight, so all joints have to be taped. When specifying, we looked at the performance we required and tried to find the product best suited to those requirements.

“We chose Kingspan insulation for the ceilings and floors because the products were the cheapest, thinnest and best performing products for that application.”

In the first floor ceiling, just 70mm of Kingspan Kooltherm K7 Pitched Roof Board formed the base layer of the property’s continuous lining. The premium performance insulation – which, due to its closed cell structure, has thermal conductivity of only 0.020 W/m.K at 70mm thickness – was tacked to the underside of the existing timber joists, contributing to an overall U-value of just over 0.10 W/m2.K.

Kingspan Kooltherm K3 Floorboard supplied the underfloor insulation for the property. The BRE Green Guide A+ rated board, which is specially designed for ground floors, was fitted between the joists of the suspended timber floors. Careful detailing contributed to the high standard of air tightness for the refurbished property and, ultimately, to a U-value for the insulated suspended floor of 0.12 W/m2.K.

Tenants moved in to the property in February 2011. Since then the ventilation heat recovery system has provided the sole heat source for the building, and the meagre number of radiators in the house (a heated towel rail purely for comfort and three other radiators installed as a back up in case the mechanical system’s performance was less than expected) have, according to Robert Prewett, not been used. “My prediction is that, in future, about 28 kWh/m2/yr of energy will be required for this property, which is very close to the Passivhaus EnerPHit refurbishment standard – and a molehill in comparison to the mountain of energy this type of house would normally use,” he said.

The Balham property, like others funded through the Retrofit for the Future competition, will be evaluated over a two-year period by the Energy Savings Trust and the potential for low-cost implementation in volume across the UK assessed.


Low carbon and recycled

Advanced performance thermally efficient windows, featuring frames manufactured solely from recycled PVC-U, have been supplied to a Birmingham sheltered housing scheme.

Manufactured by Framexpress and installed by Berben Group, 128 recycled windows were specified by Yardley Great Trust at its Foliot Fields site, a supported living scheme for older people.

Made using the new recycled low carbon Reco22 window framing system from Profile 22, the carbon footprint of the extruded window profile is just 6% of that manufactured using virgin material.

Reco22 is the first window system to secure a dedicated A+ rating across all domestic applications from the BRE earlier this year, according to the company.

Lynn Bailey, housing manager, Yardley Great Trust, said: “We try to instil a positive approach to sustainability in all of our activity from supporting residents in reducing waste to working with local suppliers and the specification, wherever possible, of products that we feel fit with our own commitments to the environment.

“At Foliot Fields we wanted to make properties warmer and importantly more secure for residents but we also looked at environmental impact and ongoing maintenance costs. We felt that this particular specification was the strongest fit to our own values.”

The 31 properties at Foliot Fields were built by Yardley Great Trust in 1984. A registered charity, the Trust was founded in 1355 and aims to relieve poverty through grants, as well as providing care and housing to older people throughout the Birmingham area.

Reco22 was launched by Profile 22 last year. In addition to cutting the carbon footprint of extruded framing material to just 6% of that of virgin material, a triple glazed option means that Reco22 delivers an advanced thermal performance achieving U-values as low as 0.8W/m2K.


Future model

Wakefield Metroglaze has played a key role in a landmark Retrofit for the Future project in Nottinghamshire which provides a model for upgrading a common 1950s and 60s house type.

The company supplied and installed high performance triple glazed Sheerframe casement windows, plus a Masterdor Thermal 54mm, triple glazed door-set, at Mayfair Place in Tuxford, Newark where improvements aim to achieve an 80% reduction in energy use of the A1 Housing property.

Very low U-values of 0.8 W/m2K for the Sheerframe windows and 1.0 W/m2K for the Masterdor Thermal door-set were instrumental in delivering a highly insulated building envelope.

This refurbishment project was entered into the Technology Strategy Board’s Retrofit for the Future competition by A1 Housing, the Almo of Bassetlaw District Council which manages 7,000 homes in Nottinghamshire.

One of the reasons the Mayfair Place house was selected for the competition was because the mid-terrace property is of Multi Frame Construction (MFC). This was a common non-standard construction method during the 1950s and 60s which means there are numerous other homes of this type across Bassetlaw and managed by RSLs nationally.

The property is constructed with a concrete structure on the ground floor and timber frame for the first floor and pitched roof. One of the most important steps taken to bring the property was brought up to 21st century low carbon standards was to significantly improve the thermal performance of the building fabric through greater wall, floor and loft insulation plus new windows and doors.

Andrew Davenport, A1 Housing’s capital works and asset manager said: “Generally speaking the retrofit house has been a huge success. Our tenant is delighted with the transformation of her home and we have a testbed which will help us deliver cost effective improvements to other similar properties in our portfolio.”

The thermally superior building fabric combines with a number of features designed to minimise energy usage including an air source heat pump, photovoltaic (PV) panels, a mechanical ventilation and heat recovery (MVHR) system and low energy appliances and lighting.


Fit for a king?

A new single-layer tapered roofing insulation system designed by Gradient Flat Roofing has been included as part of a major package of works to convert an historic Derbyshire ruin into a block of 26 luxury apartments.

Gradient was chosen for the quality of product and the level of customer service it could bring to the Riber Castle project in Derbyshire.

“This was not a particularly complex project as the original roof had disappeared completely and a new one had to be built,” explained Gradient’s Steve Adams.

“This took the form of different modules which combined to make up the overall roof. We were then able to design a bespoke insulation system, which created the various falls that were required to ensure effective drainage. We also provided general technical guidance plus on-site assistance during the installation procedure.”

A liquid vapour control layer was first laid over the new 8502m roof deck before Gradient’s foil-faced PIR boards were used to create a tapered, single-layer insulation system. The roof then received a layer of Oriented Strand Board to allow it to accept high levels of foot traffic, before a final three layer resin-based GRP waterproofed system was added. “With our single-layer system we are able to manufacture each piece of the insulation under controlled conditions at our manufacturing plant. This means that individual boards can be created to fit specific locations on the roof and the quality levels remain very high,” Steve said.

This dramatically reduced the likelihood of errors and allowed the Gradient system to be installed far more quickly and easily than would have been possible with a conventional built-up system. Gradient also supplied a variety of pre-cut mitre boards for this project, which again reduced the need for skilled on-site labour during installation

The Castle stands 600ft above sea level at the head of a valley overlooking the town of Matlock in Derbyshire. “This is an exposed location which means that the new roof has to withstand high wind speeds,” Steve said. “We were able to confirm that the wind uplift calculations provided by the Project Director Ivan White, were accurate, so that the new roof could be built in complete confidence.”

Photovoltaic precedent

At Weser-Stadion in Bremen, the largest building-integrated photovoltaic installation in Germany has enabled the generation of enough power to meet the annual demands of 300 households – and it could set a precedent for similar UK stadium applications.

Located in the north of the country and home to football team Werder Bremen, Weser-Stadion is the latest German football stadium to improve its environmental performance following the delivery of previous ‘green’ sports facilities in Freiburg, Augsburg and Stuttgart.

Covering approximately 60% of the total roof area, some 1,735 Evalon Solar panels were installed around the outer ring of the new stadium roof. This provides a full capacity output of 511 kWp and contributes to the total stadium output of more than one million kilowatt-hours of electricity per year.

ICB (Solar), a Microgeneration Certification Scheme (MCS) approved Solar PV installer, designs, supplies and installs solar PV systems from its base in Bournemouth and believes that the Weser-Stadion project could set a course for future large scale stadium installations in the UK.

Managing Director Rob Jackson said: “In Bremen, the successful combination of high performance waterproofing membranes and solar photovoltaics is the perfect collaboration of contemporary construction and energy-efficiency. The versatility and performance of the power-generating waterproofing membrane makes it ideal for modern sports facilities.”

As part of a redevelopment programme at the Weser-Stadion to improve spectator experience by moving seating closer to the football pitch, the new-look stadium would also include a brand new roof. Integrating a 1.2MWp photovoltaic system into the shape and design of the building and roof – this has helped to reduce annual CO2 emissions by 450 tonnes.

Over 10,000m2 of Alwitra Evalon Solar – a power-generating waterproofing membrane – was installed onto the roof of Germany’s Weser-Stadion.

Each membrane was mechanically fastened to the sheet metal roof using stainless steel screws, before being connected in the seam area using a hot-air welding process. The fastener spacing on each individual roof area was determined according to the results of a wind load survey, with the resulting data forming the basis of the fastening plan.

‘Green’ grocer

The 25,000ft2 unit is the first new build store that ISG has taken on for Sainsbury’s and follows a long-standing relationship that has involved numerous refurbishments, extensions and feasibility studies.

Originally planned with a conventional steel-frame design, it was re-specified as a timber-framed building following planning approval. The client’s sustainability demands continued to broaden even after the design and build project was well underway, challenging ISG to provide solutions that were both environmentally sound and economically viable.

The BREEAM ‘Very Good’ rated scheme is targeting a carbon neutral build thanks to its timber frame, pre-fabricated SIPS (Structurally Insulated Panel System) timber walls and timber roof cassettes finished in larch cladding, all of which are derived from renewable sources. The SIPS walls, designed to provide integral vapour barriers, have also enhanced the efficiency of the building envelope, delivering an air loss average of just 2.0m3/hr/m2: with an industry norm of 10.0m3/hr/m2.

The exemplary environmental performance of the building’s structure is mirrored by the eco-friendly specification throughout. Environmental features include a biomass boiler powered by waste wood pellets, rainwater harvesting and re-use for toilet flushing, LED lighting, the installation of sun pipes and daylight sensors, as well as night blinds on chiller doors to prevent cold air loss into the aisles. Externally, the store even offers charging points for electric and hybrid vehicles in the car park and a storm water drainage system, next to the store, has been planted with 40 species of native trees and shrubs to create natural habitats and encourage wildlife.

Rob Martin, ISG’s operations director of UK Retail, said: “We have been among a handful of Sainsbury’s preferred contractors for some time, so winning the design and build contract for one of the company’s ground breaking ‘eco’ stores is a massive coup for ISG.

“This store not only sets the bar high for environmentally-friendly supermarkets, it also has a unique and attractive aesthetic and provides a high quality shopping experience. It will set a benchmark for future supermarket developments, demonstrating how a ‘greener’ store can also be attractive, practical, cost-effective and economically viable.”

Significant savings at a sensible cost

Regional developer Cawrey Homes has specified Swish fascias, soffits and cladding in hazy grey for its new eco development, Fielding Meadow.

The Leicestershire-based house builder is now in the closing stages of the 36 home development in Ratby.

The two-, three- and four-bedroomed homes have been designed to incorporate the latest energy saving technology to achieve a Code for Sustainable Homes level four rating.

Also including a focus on long-term maintenance savings, the properties feature low maintenance fascias and soffits from Swish Building Products and external cladding, used by Cawrey to house solar panels.

Dave Walgate, Buyer for Cawrey, said: “We wanted a development which delivered significant energy and lifetime savings at a sensible cost.

More broadly, the development features air source heat pumps, thermally efficient windows, insulated floors and ‘green’ sedum roofs. “We put a lot of emphasis on the building envelope and energy efficiency for example, increasing cavity wall insulation from 75mm to 200mm but also looked at the long-term maintenance costs of the properties.

“Natural wood finishes clearly look good but at height need regular maintenance and that equates to higher costs. The Swish products in hazy grey delivered a strong aesthetic quality and critically required little to no future maintenance.”

Swish Building Products recently joined a handful of companies that have secured the responsible sourcing standard BES6001 delivering instant point gains to house builders under the Code for Sustainable Homes and Eco Homes.

In securing the standard across its PVC fascia, soffit, cladding and window board ranges Swish Building Products is able to offer developers maximum points under the Code (tier level 1), matching FSC timber specifications in Mat2 and Mat3.

Greg Wilde, Swish Building Products, said: “Roofline maintenance costs can be significant, in part because roofline products are in exposed locations and because maintaining or repairing them at height is more complicated and therefore more costly.”


Largest carbon zero development

Wakefield and District Housing (WDH), a registered provider with more than 31,000 homes, opened the doors to Park Dale, the UK’s largest zero carbon housing development at the official launch event earlier this month.

Working closely with community regeneration specialist Keepmoat and property design and management consultants NPS, the pioneering £12 million project consists of 91 homes to Level 6 of the Government’s Code for Sustainable Homes.

From the outset Park Dale, in Airedale, West Yorkshire, was designed to offer a realistic and affordable solution to achieve zero carbon at large scale.

To keep costs down, Keepmoat used block and brick work to achieve superior air tightness, rather than the prefabricated methods of construction conventionally used in zero carbon build. In turn, the use of traditional build methods has had a beneficial impact on the local economy, maximising employment opportunities for local trades people.

With part funding of £5.77 million from the Homes and Communities Agency, Park Dale includes 71 homes for social rent and 20 for intermediate rent.

Each of the two, three and four-bedroom homes uses mechanical ventilation heat recovery systems and has in-roof photovoltaic panels, superior levels of internal air tightness and grey water recycling.

The homes draw heat from a district biomass heating system powered by renewable wood pellets produced in Yorkshire from recycled pallets. The development also includes a Learning Centre where residents can find out how to make energy savings and take qualifications in energy management.

Park Dale took 12 months to plan and to coordinate the Code for Sustainable Homes submission. Work started on site in March 2010.

Trades people from across Yorkshire have worked on the project, many of whom learned new skills in order to build to high standards of energy efficiency. More than 40 apprentices also gained eco-experience on the site during the build.

Keepmoat worked with WDH to explore and test renewable technologies to ensure products chosen for Park Dale gave confidence and best value, factoring in long-term maintenance costs.

Heating demand is expected to be one fifth of an average home. Total energy bills are expected to be 40% less than an average home and 25% less than a modern new build home. Other benefits will include water bill savings from lower water use fittings and grey water recycling, and the potential to save more on bills by using appliances during the day when the photovoltaic panels will power for free.

WDH chief executive, Kevin Dodd, said: “WDH is very proud that we have created the UK’s largest zero carbon housing development. In addition to the creative look of the homes, they offer fantastic savings on energy bills. The entire project has had some outstanding benefits for the local community, including the WDH apprentices who learned many skills while working on the site.”


Community project

A community hydro-electric scheme is to go ahead after it raised £125,000 in three months from a share issue which gave people the chance to back renewable energy.

Esk Valley Community Energy Group aims to establish a small-scale hydro-electric turbine known as an Archimedes' screw on the River Esk in Ruswarp, near Whitby, North Yorkshire.

The project attracted enough social investment, in the form of loans and grants, to make the directors approve the next phase.

When the scheme is completed in summer 2012, the ‘fish-friendly” turbine will generate around 200,000 kWh of sustainable energy a year, saving an estimated 3,000 tonnes of carbon emissions in its lifetime.

Colin Mather, retired civil engineer and chair of the energy group, said: "One of our sayings is 'think global, act local' and our scheme offers people a chance to do their bit to protect the environment while generating a new source of sustainable green energy.

"We are delighted with the response to the share issue and although we know that there is still a lot of hard work ahead, it illustrates that by working together, co-operating, amazing things can be achieved."

The community share issue is still open, with shares available from as little as £250 up to a maximum of £20,000, to allow the group to reduce loans.

A recent report by YouGov found that 42% of Brits with private wealth want to get involved with ethical and social investment.

Green living

A ZinCo green roof from Alumasc has provided a pleasant recreational space for residents of a new housing scheme in Guernsey.

Designed by architects Lovell Ozanne and Partners, the Hougue a La Perre housing development is situated on the northern outskirts of St Peter Port and is managed by Guernsey Housing Association.

The project involves the development of 77 houses and flats constructed in 2009 on the site of the former Grand Bouet bus depot for Guernsey Housing Association in partnership with the States of Guernsey Housing Department, in order to create a sustainable and attractive neighbourhood.

The ZinCo green roof from Alumasc was specified for the podium deck above an underground car-park, which forms a courtyard for use by the residents. The 1200m2 intensive green roof will offer notable ecological and amenity benefits, providing a natural habitat for plants and wildlife, while helping to reduce air and noise pollution, cutting carbon emissions and assisting with rainwater retention and attenuation.

ZinCo green roofs vary from extensive and biodiverse types which require minimal irrigation and maintenance, to intensive roofs such as the one at Hougue a La Perre, which are suited for areas of public and recreational use and require more tending.

The roof was installed over Hydrotech MM6125 structural waterproofing, also from Alumasc.

The Main contractor on the Hougue a La Perre project was Charles Le Quesne (Guernsey) Ltd.


Finding a low energy space

A Nottinghamshire local authority, which won the 2011 Low Carbon Council of the Year award, is the latest to upgrade to ‘intelligent’ energy-saving lighting from Chalmor for two of its largest town centre car parks.

Mansfield District Council is making savings of £22,569 and 132.88 tonnes of CO2 per year by using Chalmor’s low energy lighting with motion and photo controls. This has been installed in the Four Seasons shopping centre car park and the Walkden Street car park, which jointly offer 936 parking spaces.

Mansfield’s climate change officer, Helen Bartle and colleagues saw Chalmor’s latest low energy lighting demonstrated at the ESTA (Energy Services and Technology Association) exhibition in Manchester last year.

Chalmor’s ‘smart’ lighting and controls are operated by time controls, outside light levels and occupancy sensors or any permutation of the three. The company’s Refit T5 system, installed at both these Mansfield town centre car parks, replaces older fluorescent fittings by the latest new generation T5 fluorescent technology offering cost savings and reducing energy consumption.

The T5 fluorescent lamp technology consumes less energy and depreciates little over its lifetime – 6% compared to 30% over the former lighting. Each of the car parks uses one of Chalmor’s Autolux six-channel controllers and two weatherproof light level sensors to maximise energy-savings by making use of daylight and time sensors.

Autolux is also temperature-sensitive and this is used to switch perimeter lights back on again when the temperature reaches zero. Autolux also controls the roof and perimiter lighting that were not replaced to keep these lights off during the night when the car parks are closed.

Chalmor’s national sector manager, Colin Childs, said: “By offering Mansfield District Council savings of nearly £30,000 a year with savings of 168 tonnes of CO2 emissions yearly, this project has at the same time delivered a safer environment offering increased light levels and both day and night time lighting control.”


Sustainable boardwalks

A sure-footed solution to accessing environmental education in Yorkshire has been made possible with boardwalks ‘more sustainable than wood’ – made entirely from recycled plastic carrier bags and bottles.

A 30m-long walkway, 6m bridge and pond dipping platform built from Centriforce recycled plastic posts and planks are supporting safe and slip-free fieldwork by students visiting the pioneering Carlshead Farm near Wetherby.

The award-winning 273-hectare farm in the lower Wharfedale Valley is a leading national example of innovation and diversification in farming with a range of complementary educational and environmental projects, including a biomass plantation and a training centre for excluded teenagers.

Consultant ‘Environments for People’ designed and built the boardwalks to facilitate educational visits by local primary and special needs schools, providing raised access across boggy ground and a low-lying platform for pupils to get up close and safely explore pond wildlife.

Using recycled plastic profiles instead of wood provided a more durable and maintenance-free solution that was also more practical to design and build, explained Hugh Roberts from Environments for People.

“Unlike the wooden alternative, Centriforce planks have a slip-resistant and splinter-free surface, and don’t need to be fixed with chicken wire or nails,” he said. “So the children have a safe platform to walk, or even to lie on to investigate wildlife habitats.”

Centriforce recycled plastic posts and bearers are built to form the base structure of the walkways. The plank-like decking is laid on top and finished with an edging strip. Manufactured from 100% HDPE post-consumer waste, the recycled plastic profiles can be drilled and sawn like timber and designed into any shape.

“During construction, the recycled plastic is very forgiving,” continued Hugh. “The Centriforce profiles do not deform, chip or split. A treated wooden post can easily split when driven into the ground causing rot and leaching chemicals into the soil; a recycled plastic post is completely inert.

“Centriforce profiles offer a truly sustainable solution. There’s no maintenance and no ongoing cost involved in looking after the boardwalk. Even on wet and marshy ground, the boardwalk is rot and algae-free, but still looks and feels like wood and blends nicely with the environment.”


Zero carbon journey

Miller Homes has built five identical Miller Zero houses to different levels of the Code for Sustainable Homes in Basingstoke.

These homes, which are the same in layout to others on the site of 79 units, have been completed to Code levels 1, 3, 4, 5 and zero-carbon 6.

The CfSH houses are among 79 homes for sale on this development. Miller had planning permission for these houses based on 2006 Building Regulations; but as an R&D project, it was decided to construct some of these homes to various levels of the Code for Sustainable Homes.

The company wanted to know what the development costs would be between each of the Levels and how much consumers would be prepared to pay for homes created to the Code for Sustainable Homes.

Building as cheaply as possible was not a consideration for Miller, it was about achieving the different Code Levels using different types of materials and construction methods. The company also realised it would be the first time that any house builder would test this decision on the open market.

Having tested how the additional construction costs compare, Miller Homes is now researching the public appeal of homes built to different levels. Once sold, each of the homes will be monitored by Miller (with the approval of the owners) to collect data on their lifestyles. The model can then be value-engineered towards possible future sites nationwide.

The Code level 6 home is super-insulated with the external walls built using H+H’s 200mm Vertical Elements. The Elements themselves have excellent thermal insulation properties = 0.11 W/mK with a compressive strength of 3.0 N/mm2. The Vertical Elements in combination with 200mm Webbertherm insulation and render achieved a U-value as low as 0.09 W/m2K.

Excellent levels of airtightness were also achieved to help meet the mandatory heat loss parameter required for Code 6 Homes of 0.8 W/m2K. This is aided by the fact that the Vertical Elements’ larger panel surface areas of aircrete mean fewer joints, higher levels of air-tightness and improved speed of build.

The extra costs of all the Code level homes was identified almost entirely from the addition of the renewable technology required such as a ground source heat pump and photovoltaics, rather than the fabric of the buildings.

• The Code 3 house cost between £5,000 and £7,000 more than a house typically specified to meet the Building Regulations.
• The Code 4 house cost between an extra £7,000 and £10,000.
• The Code 6 house’s cost to build however was £50,000 more.

Miller Homes wants to work closely with the occupiers to understand what the impact, if any, the code-home features.

Recycled floor

Tarkett iQ Megalit vinyl tiles were installed throughout the new single storey extension of the Law School at Newcastle University.

Ces Maddison, of project architects Tench Maddison Ash, explained the choice of flooring: “All materials were selected for their sustainable properties using the BRE green guide to specification. We chose Tarkett’s vinyl floor finishes for their recycled material content and long life/low maintenance characteristics. They give a stunning finish to the new main entrance.”

Megalit is one of Tarkett’s iQ floorings. Made with high quality raw materials, iQ Megalit needs no wax or polish throughout its life, with a third generation PUR reinforcement that requires the absolute minimum of heavy, wet cleaning. Thanks to its Unique Surface Restoration, simple dry buffing will fully restore the flooring surface to its original appearance and properties, minimising maintenance costs. The reduced use of water, chemicals and energy add to its excellent environmental profile. iQ Megalit is also one of the first homogeneous floorings to achieve the highest wear group classification, class T, EN660-2, ensuring it can withstand heavy daily traffic.

For the entrance to the Law School, contrasting wall and floor finishes were used to comply with DDA requirements. A mix of dark colours and lighter borders were employed for the flooring in circulation routes, with the colour scheme designed to reflect that used in the garments of the judiciary.

Seeing the wood and the trees

The Hicks Lodge Cycle Centre project, completed by Robert Woodhead for the Forestry Commission, achieved second place in this year’s EMCBE (East Midlands Centre for Constructing the Built Environment) Environmental Sustainability Award category.

Craig Pygall of Woodhead said: “With 11 other strong finalists, achieving second place on the night was a great accomplishment. The project as a whole was a fantastic achievement for us. We worked really well as a team; the Forestry Commission, the National Forest Company, Pick Everard Architects and ourselves.

“It was truly a delightful project and is a great facility for the local community near Moira in Leicestershire.”

Incorporating Woodhead’s knowledge of green technologies, Hicks Lodge uses sustainable timber throughout, solar panels, a biomass boiler, a sustainable urban drainage (SUD) system in an airtight structure – all design elements which make a significant contribution to sustainable development principles.

Set in the National Forest the project is designed to BREEAM Excellent standard. Only one site skip was used with less than 3% of waste going to landfill.

Landmark storm controln

ACO Water Management’s cellular attenuation system, ACO StormTank, has been selected to provide surface water storage at Centenary Quay – Southampton’s new landmark regeneration project.

A key component of a sustainable drainage system serving the site’s car parking and footway areas, the StormTank proposal, which positioned the tank next to a new Section 38 highway, is one of the first to be Category ‘O’ certified having met the adopting highways authority’s strict structural performance criteria.

The £500 million Centenary Quay redevelopment will transform the former Vosper Thornycroft shipyard into a vibrant mix of new homes, leisure and community facilities, shops and offices. Funded through a partnership of the South East England Development Agency (SEEDA), Southampton City Council and the private sector, the scheme also includes a new Maritime and Marine Innovation Quarter.

Sized to attenuate the surface water run-off that would arise from a 1 in 100 year storm coinciding with a 1 in 200 year high tide – together with a 30% allowance for climate change – the tank would need to withstand the lateral and sheering loads exerted by passing traffic using the new adjacent highway. The challenge facing consulting engineers Capita Symonds was to find a tank manufacturer that could support the proposed scheme with a rigorous structural analysis of its in-situ performance.

“ACO was the only potential supplier who could provide the quality of information and level of detail we needed to satisfy the adopting highway authority,” Robert Cooper, principal engineer at Capita Symonds, said. “The technical assessment compiled by ACO’s Design Services Team formed a vital part of the overall Section 38 submission which was subsequently fully approved.”

The 120m3 ACO StormTank at Centenary Quay has a recessed edge profile along one side to avoid any direct vertical loading from a series of off-line parking bays on the highway. Configured to attenuate all the water it receives, the tank is encased in an impermeable welded geomembrane which is then wrapped in a protective outer fleece – a combination that achieves a fully watertight and stable installation. When tidal conditions permit, the tank discharges to the adjacent River Itchen through a conventional non-return valve outlet.

ACO StormTank’s design uses high strength central pillars and side walls to provide load bearing capacity and structural integrity. A completed tank only requires side panels at its perimeter to provide lateral support. The result is a totally barrier free interior void that can be easily accessed, inspected and cleaned. The free flow of storm water entering the tank also avoids having to use expensive pipe manifolds and additional pipework to distribute flow evenly.