The government’s response to its 2019 Future Homes Standard consultation gives us a clearer picture of what the homes of 2050 might look like. But is it a workable vision? And does it go far enough? Nick Gander and Rod Davies of far-infrared heating specialists Energy Carbon give their take.

In January, as millions of people adjusted to life under the third national coronavirus lockdown, the government quietly released a document with sweeping implications for the future of UK construction.
The Future Homes Standard is Whitehall’s attempt to dramatically reduce the environmental damage caused by Britain’s houses and its housebuilding sector, as part of broader efforts to achieve net-zero carbon by 2050.  Its aim is simple, but far-reaching. It’s designed to cut the carbon produced by the average new-build house by between 75 and 80% in the coming years – something that would make a huge contribution to that quest for net-zero.

In October 2019, the government put its initial proposals to the public and interested experts in the form of a consultation. It was the response to that consultation that they released at the start of this year.
Originally, ministers had intended to introduce interim measures in 2020 to strengthen Building Regulations as a stepping-stone to the full Future Homes Standard. These measures would aim to cut the carbon emissions of the average new-build by 31%.  Unsurprisingly, given the vast disruption caused by the coronavirus pandemic, this was postponed.  In its consultation response, however, the government announced that this interim phase would begin in 2021. Details will be finalised by December 2021, before coming into force officially in June 2022.

The wheels starting to turn?
We also got some much-needed clarification about exactly what the measures would entail.  With its interim ‘stepping-stone’ to the full Future Homes Standard, the government’s aim is to ensure that new-built homes are not installed with fossil fuel heating after 2025, and won’t require further retrofitting to make them fit for 2050.  The government is also set to close the loophole that’s previously allowed builders to only have to meet the energy efficiency standards that were in place when a development first started, even if those standards change in the meantime.

From now on, rules will apply to individual buildings, not whole developments.  These are all extremely welcome moves. It feels like, finally, the wheels of the urgently-needed net-zero transition are starting to turn.  However, there are aspects of the government’s proposals we’re less impressed with.

No magic bullet
In their consultation response, ministers explicitly say that “low carbon heating systems will be integral to the specification of the Future Homes Standard”.  However, they then go on to say that “we anticipate that heat pumps will become the primary heating technology for new homes”.  At Energy Carbon, we’ve long been arguing that there’s no magic bullet solution to low-carbon heating, and that in 2050, we’re likely to draw on a variety of different technologies to help us heat homes both sustainably and efficiently. We believe that air-source and ground-source heat pumps have their place – but they come with their own issues.

The first relates to their longevity. Heat pumps aren’t just very expensive, they require increasingly expensive annual maintenance visits, and even then, a heat pump product installed today is likely to need replacing a number of times between now and 2050.  That means a huge amount more embodied carbon (a yardstick of sustainability that the government short-sightedly aren’t using as part of the Future Homes Standard as it stands) – and many heat pump products use refrigerants that themselves contribute to global warming when they’re released into the atmosphere.  What’s more, heat pumps are extremely complex products – meaning any maintenance or replacement work requires the services of specialist engineers, who, for the moment at least, are very few and far between.  We therefore believe that the government is being very short-sighted by presenting this one heating technology as the solution to a complex problem – a problem likely to need all sorts of different systems to properly address.

The case for infra-red
So far in any of its documentation relating to the Future Homes Standard, the government is yet to mention the huge potential of our own area of expertise – far-infrared.
Infrared refers to a division of the electromagnetic spectrum. Within that division, there are three types of infra-red radiation: near infrared, mid infrared and far-infrared – and it’s far-infrared that’s by far the most beneficial for heating homes and its occupants.  In fact, it’s the exact same frequency of light called ‘the light of life’ generated by the sun, invisible to the naked eye, but capable of warming us directly.
Far-infrared radiation warms all the surfaces and objects in a room, rather than the air – and those surfaces and objects then go on to radiate heat themselves.  The embodied heat gathered in these areas slowly releases back into the room, letting occupants turn down the thermostat.  This in turn allows for a very fast reaction time to perfectly control the room temperature.  Its fast reaction times mean occupiers feel the benefits within minutes of the thermostat switching back on – saving energy, and cutting carbon emissions.

We believe it can make a major contribution to the collective effort to reach zero carbon by 2050 – and we call on the government to seriously consider promoting its use as part of the Future Homes Standard.

 

www.energycarbon.co.uk

 

The existing Borssele nuclear power plant (Image: EPZ)

EPZ, operator of the Borssele nuclear power plant, has called for an extension to its operation beyond 2033 and/or the construction of two new large reactors at the site in order to help the Netherlands meet its energy and climate goals. The company’s director, Carlo Wolters, presented EPZ’s vision yesterday at a parliamentary debate on the role of nuclear power in the Dutch energy system.

Nuclear power has a small role in the Dutch electricity supply, with the 485 MWe (net) Borssele pressurised water reactor providing about 3% of total generation. The plant was built by Siemens and has been in operation since 1973. It is scheduled to close in 2033.

In a position paper published on 28 November, EPZ said electrification in many areas of the energy sector will lead to a sharp rise in power demand in the Netherlands over the next 15 years. “EPZ foresees that all climate-neutral electricity sources must be used for to meet this increasing electricity demand,” it said.

“As far as EPZ is concerned, nuclear energy is also in the future under certain conditions one of these climate neutral sources …  Two options (or a combination thereof) are obvious,” it said. These are an extension to the operation of the existing Borssele reactor and/or the construction of two new reactors on the same site.

EPZ said it wants to investigate, together with the government, what the technical-economic preconditions are for an extension after 2033 of the current Borssele reactor. An operating time extension of 10 to 20 years is possible, it said. It noted that a letter from EPZ about this had already been sent to Minister for Economic Affairs and Climate Policy Eric Wiebes and the House of Representatives. Any market risk must be covered in the business case for the extension, EPZ said.

EPZ is in favour of constructing two new 1500 MWe reactors at Borssele before the mid-1930s. It said a precondition is the choice of a proven (and licensed) reactor design of which the permit and consultation processes can be completed on time. Subsequently, during the construction no changes to design and regulations are made. Finally it is necessary that any market risk in the business case is covered by the government.

“With an adequate project progression, the costs of a new Generation III reactor are between EUR8 and EUR10 billion and the construction time is about eight years,” EPZ said.

With a combination of these two options, by the mid-2030s the installed climate-neutral capacity at Borssele could be about 3500 MWe, with an availability of 90%, EPZ said. This would be sufficient to meet about 25% of current Dutch electricity demand.

“A fully climate-neutral energy system by 2050 remains within reach, even if electricity consumption continues to increase,” it said. If it keeps the existing Borssele reactor operating and constructs two new ones, the emission of about 13 megatonnes of carbon dioxide will be avoided, it added.

However, EPZ said government support will be needed for nuclear new build to be an option. The government must set financial and political-social frameworks (permits, financial guarantees and sureties). “This gives investors the guarantee that investments made over the long exploitation period can be recouped from a nuclear power plant.” It added, “Only the government can set and monitor the necessary frameworks.”

The Netherlands is considering the expansion of nuclear power in its energy mix, according to a letter Wiebes submitted to the Dutch parliament in September, together with a report by consultants Enco. The cabinet is now preparing a motion requesting that the country holds a market consultation to assess commercial interest in nuclear new build.

 

Source: World Nuclear News

 

 

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Image credit: Dogger Bank

The project will have three phases and will power up six million homes per year

 

The UK, already the world’s leader in offshore wind, is getting ready to start construction of what will be the world’s biggest offshore wind park, Dogger Bank. The British utility company SSE and the Norwegian energy firm Equinor agreed to invest $8 billion in the project, which will be used to build the first two phases.

Dogger Bank is an isolated sandbank within the central to southern North Sea spanning UK, German, Danish and Dutch waters. The area was a landmass connecting the UK to mainland Europe. As the sea level rose after the last ice age, Dogger Bank became an island before being completely covered by water about 8,000 years ago.

The wind farm is being developed in three phases, Dogger Bank A, Dogger Bank B, and Dogger Bank C, located between 130km and 190km from the North East coast of England. Collectively they will become the world’s largest offshore wind farm. Each phase will have an installed generation capacity of up to 1.2 gigawatts (GW).

The construction of the first two phases, with 2.4 GW capacity, will be financed by a group of 29 banks and three credit export agencies. They will be built at the same time starting in 2021 to maximize the synergies due to their geographical proximity and make use of common technology and contractors.

The project will be the first to feature the 13MW General Electric (GE) Haliade-X, the largest wind turbine in the world. One rotation of the Haliade-X is estimated to power a British home for two days. Once completed, Dogger Bank will power up to six million homes annually in the UK, equivalent to 5% of the country’s electricity demand.

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Alistair Phillips-Davies, SSE Chief Executive, said in a statement: “We are putting our money where our mouth is on delivering net-zero and reinforcing the UK’s position as a world leader. This investment will help drive a green recovery from coronavirus through the project’s construction over the next five years.”

The UK is already the world leader in offshore wind, with more installed capacity than any other country. Offshore wind now powers the equivalent of 4.5 million homes per year and in many areas, wind is now the lowest cost option for new power in the UK, cheaper than new fossil fuel or nuclear power projects.

UK Primer Minister Boris Johnson announced this year a plan for offshore wind to power every home in the UK by 2030. This will require a $66 billion in investment and the equivalent of one turbine to be installed every weekday for the whole of the next decade, an analysis by Aurora Energy Research.

“Your kettle, your washing machine, your cooker, your heating, your plug-in electric vehicle – the whole lot of them will get their juice cleanly and without guilt from the breezes that blow around these islands,” Johnson said in a press conference in October, as part of a “build back greener” initiative.

Source: ZME science

 

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Building sensors could be crucial in driving environmental initiatives, such as the UK government’s pledge for carbon-neutral status by 2050

#carbonneutral #climatechange #smartbuildings #construction

The built environment contributes around 40% of the UK’s total carbon footprint. Unfortunately, around half of this is from the energy used in buildings. Whilst many newly constructed dwellings are designed to be more energy-efficient, a major priority is decarbonising the existing building stock, of which 80% will still be standing when the UK is to meet its carbon-neutral status by 2050. In light of Energy Efficiency Day, Stacey Lucas from Sontay explains how the presence of building sensors optimise energy performance in both new and older buildings, driving the stock towards the all-important smartness and efficiency that is essential to the current and future health of our environment.

Building sensors, installed as part of an efficient central management system, offer an ingeniously smart and effective way of remotely monitoring elements such as temperature, air quality and ventilation. In doing so, not only do they help maintain a healthy indoor climate for the occupiers’ comfort and peace of mind, sensors give property owners more agency over energy usage; a benefit that not only helps reduce heating and lighting costs, but also facilitates a significant reduction in a building’s carbon footprint. Their usage could therefore be crucial in driving environmental initiatives, such as the UK government’s pledge for carbon-neutral status by 2050.

It is in no doubt, then, that sensors have found themselves at the heart of what we call smart buildings. According to the ‘Smart Building: Energy efficiency application’ document produced by the European Commission’s Digital Transformation Monitor, a smart building is defined as ‘a set of communication technologies enabling different objects, sensors and functions within a building to communicate and interact with each other and also to be managed, controlled and automated in a remote way.’ Sensors are smart devices that sense when and how a building’s energy performance can be adapted, consistently monitoring, measuring and evaluating data which feeds into a central management or control system.

The rise of smart sensors

A control system’s sustenance, sensors play an essential role in the energy-efficient operation of a smart building. Sontay’s smart sensors in particular offer full environmental sensing in a single device. This ingenious sensor can measure a myriad of elements including temperature, RH, CO2, light level, and occupancy or local devices independently. Typically, traditional sensors require up to seven cable inputs into a controller, making for a lengthy installation. A Sontay smart sensor, however, only needs a single cable connection to perform the same duty with greater efficiency, and can be mapped to any device or freely programmed into a building’s network.

Efficiency can also be related to the health and wellbeing of occupants, as well as the climate. In terms of air quality, airborne volatile organic compounds (VOC), pollutants which are found in paints and other building materials, are known to have a detrimental effect. The same harmful chemicals are also present in hand sanitisers, aggressive cleaning products and detergents, the demand for which has been unprecedented since the onset of the coronavirus crisis. Air quality sensors are able to measure VOC levels and alert the control system or occupants of the need to take action when a potentially hazardous reading is recorded to allow for ventilation to kick in.

 

 

There are also sensors available which prevent the unwelcome pervasion of CO2 in an over-inhabited space. A CO2 sensor with an LED traffic light-style display is a potential remedy for this issue. When showing green, the sensor is indicating that a room isn’t over-occupied and the risk to air quality is low. Should the sensor show amber, it’s a sign that windows require opening or fewer people need to be in the room to maintain the same healthy indoor environment. When the sensor turns red it is a call to action, as it indicates there is not enough ventilation and possible over occupancy in the room. At these last two stages, if a sensor is connected to a building management system, it will activate relevant ventilation procedure in order to ensure a space’s occupants do not feel uncomfortable.

Controlling a whole host of elements including heating, cooling and lighting, smart building sensors can ensure dwellings run as energy efficiently as possible. Although small in size, sensors offer fierce capability, and will go some way to enabling both new and older buildings perform well into the future, for the benefit of our beloved environment. It only seems natural, therefore, to celebrate the humble building sensor on this Energy Efficiency Day.

For more information please visit  https://www.sontay.com/en-gb/

A blended design of social housing apartments designed around Passivhaus principles

#constructionindustry #sustainable #architects #local authorities #contractors #developers #innovation #building technology #mmc #passivhaus #socialhousing #airtightness

Protect BarriAir and reflective VC Foil Ultra, the air and vapour control layers from Protect Membranes, have been specified and installed by specialist design and build contractors Stewart & Shields in Scotland’s first multi-storey Passivhaus building. 

Used as part of a residential conversion project at Old Carntyne Church, a semi-derelict building in Glasgow, the construction involved mixing traditional construction with new, with the church structure being restored alongside a new build extension which was built offsite.  The result was a blended design of social housing apartments designed around Passivhaus principles with the overall aim of contributing to the elimination of fuel poverty, on behalf of client Shettleston Housing Association.

The development, funded through Glasgow’s Affordable Housing Supply Programme and renamed Cunningham House has transformed the building into one of Scotland’s most
energy-efficient affordable housing developments and is the city’s largest Passivhaus development to date, designed to extremely high standards of energy efficiency and airtightness. The development won the Best Affordable Housing Development (Urban) category at the 2019 Inside Housing Development Awards with Stewart & Shields also being nominated as a finalist in the Scottish Home Awards for the project.

Working with Page Park Architects for the main project design and John Gilbert Architects to ensure the Passivhaus Standard was designed into the scheme, Stewart & Shields delivered a total of nineteen apartments. Fourteen of these were modified and conventionally built flats within the existing church structure, incorporating thirteen amenity flats and a semi-detached three bedroom home with five units being constructed within the new build timber frame five-storey tower extension which was built to full Passivhaus Standard and is independently certified by the Passive House Institute. With strict levels of airtightness levels and vapour control required in order to deliver energy efficiency on the project, Stewart & Shields turned to Protect Membranes for a solution.

 

Derek McIlreavy, Business Development and Design Manager at Stewart & Shields Ltd commented, “The specification of materials for this development was based on the need for a high quality end result to meet Passivhaus criteria.  We knew that Protect BarriAir and VC Foil Ultra would be up to the job in terms of airtightness to help us achieve the critical results needed to be independently certified.

We had to beat 0.6 ach-1 @50Pa for airtightness and our tests showed a result of 0.33 which overall gave an added value solution to our
client that helps to future proof these homes going forward.”

Protect’s BarriAir and VC Foil Ultra membranes form part of a comprehensive range of wall, ceiling and floor construction membranes alongside roofing underlays and accessories which are ideal for both traditional and offsite construction, with a portfolio to help ensure the whole building envelope and internal structure can be controlled in terms of moisture management, condensation control and thermal resistance.

For details of how Protect products can be incorporated into both residential and commercial builds, please visit the website,

www.protectmembranes.com

The design of the blocks is such that they require no mortar or adhesive

#constructionindustry #architects #localauthorities #contractors #developers #buildingtechnology #mmc #clayblocksystem #thinjointadhesive #structural @evolvedsupplys

The JUWO Evolved SmartWall™ Building System – thin joint masonry for the future

The Evolved Supplies JUWO Evolved SmartWall™ building system consists of a monolithic clay block system which gives a modern method of construction with thin joint adhesive technology.

The design of the blocks is such that they require no mortar or adhesive on the interlocking vertical joints. The fired, aerated clay blocks are manufactured to a tolerance of 1mm in height and come as a complete system that includes lintels, corner and shaped blocks, insulated mortar, adhesive and applicators.

These structural blocks have been used for many years across Europe and are suitable for load bearing and non-load bearing walls, for external & internal applications. They have full LABC approval and comply to BS EN 771-1 and carry the CE mark with an A1 fire rating, making them the ideal building system for low and high rise developments as well as for the self-builder.

SmartWall™ Benefits
• Excellent Thermal Performance.
•  Meets & Exceeds Building Regulation requirements.
• Quick Construction Time.
• Single solid wall construction.
• Modern Method of Construction
• Thin bed mortar technology
• Complete Building System.
• 85% less moisture in construction
• Completely Vapour permeable
• External Insulation to give that ‘tea cosy’ effect

Clay is possibly one of the most sustainable materials used in construction. It is a natural material that it easy to work with and provides a comfortable living environment.

SmartWall™ explained
The Smart Wall system delivers a much faster build time. The thin joint adhesive allows you to continually work without being restricted to the number of lifts in a day, on average, up to 40sqm can be achieved per person per day.

SmartWall™, being a monolithic building system, means that you have just one skin for your building structure, no cavity, therefore minimising areas for complicated detailing and areas for insulation to be missed.

 

 

With standard masonry systems, drying out can be problematic in the UK climate. The adhesive layer helps to reduce moisture in the building by over 85%, this, coupled with the faster build time, means that your building can be roofed and weathertight in a much shorter period of time.

The adhesive mortar comes as part of the SmartWall™ system & has been designed for use in temperatures from 0°C, so winter working is not a problem.

Efficiencies & Performance
The SmartWall™ building system has a superior thermal performance compared to other similar products, making it easy to achieve Building Regulation requirements without the need for additional wall insulation or increase in foundation size.

The thermal performance of SmartWall™, together with the density of the blocks, provide excellent thermal mass. Too many modern homes face the risk of summer overheating. The SmartWall™ system provides warmth in Winter and comfort in Summer. The clay will also regulate humidity levels within the home and it is recommended that a mineral plaster finish is applied directly to the blocks to maximise this performance.

Air tightness is achieved by applying a ‘parging’ coat of wet plaster to the inner face of the blocks. This is a standard method of achieving good air tightness and recommended by the Passivhaus Institute.

By applying a vapour open render finish to the external surface of the blocks, coupled with the mineral plaster inner finish, SmartWall™ provides a complete vapour open system. Thermal modelling shows that interstitial condensation will not form within the construction.

The SmartWall™ system provides a thermal bridge free method of construction without the need for complicated detailing.

Being manufactured from clay, the SmartWall™ blocks have an inherently good fire performance and have a rating of A1 reaction to fire.

The SmartWall™ System has been developed for anyone to use and Evolved Supplies can provide ‘on-site’ training, if requested.

For more information, visit the website or call 01691 707100.

www.evolvedsupplies.co.uk

URBAN UNION GOES GREEN WITH ELECTRIC CAR CHARGING POINTS

Scottish home builder Urban Union is encouraging greener living at its Muirton Living development in Perth by installing electric car charging points.

Delivering two charging points to the development, Urban Union hopes to encourage residents to consider opting for plug-in hybrid vehicles by giving them a convenient place to recharge them.

Plug-in hybrid vehicles combine petrol, diesel or alternative fuelled engines with a battery and electric motor, meaning they are more environmentally friendly, reducing air pollution by producing less harmful exhaust emissions.

Neil McKay, Managing Director at Urban Union said: “Cutting environmental emissions is something that all businesses and individuals should be moving towards. We wanted to make it easy for residents at Muirton Living to choose the environmentally friendly option, so that if they did decide to opt for a hybrid vehicle, they can easily plug it in to charge at the development.”

Andrew Kilpatrick, Director of Assets at Caledonia Housing Association said “Working with Urban Union to deliver the electric charging points provides another great environmental facility for the Muirton community. We are delighted to be launching a Muirton community electric car with Co Wheels later in the year which will be able use the charging points and provide convenient access to affordable transport for our Muirton residents.”

Muirton Living is home to a collection of immaculate properties including The Grant, a beautifully presented one bedroom apartment perfect for first time buyers. Available from £105,000, The Grant also comes with a variety of incentives including Help to Buy which enables first time buyers to purchase their home with only a 5 per cent deposit.

The development is ideally situated to make the most of the town’s many amenities, bars and restaurants making it the perfect place for young professionals.

For more information visit www.urbanunionltd.co.uk or call 0131 343 3391.

On June 10th, the government is set to publish its final proposals for the long-awaited Smart Export Guarantee (SEG). By the end of the year qualifying suppliers with more than 150,000 customers will be legally required to offer terms of payment for the surplus power that new solar homes put on the grid. Smaller suppliers are also able to offer a Smart Export Guarantee on a voluntary basis. 

The STA wants to see a competitive market develop to purchase power from smart, solar homes. It will be watching the market very closely for developments and ranking all offers via its online Smart Export Guarantee league table, so that new solar households can easily understand which companies are making the best offers.

Currently only Octopus Energy, on a voluntary basis, has a tariff for solar exports, for which it is offering a fair market rate.

STA Director of Advocacy and New Markets Léonie Greene said; “We will be watching the market like a hawk to see if competitive offers come forward that properly value the power that smart solar homes can contribute to the decarbonising electricity grid. The net zero energy transition we need cannot happen without the active engagement of the public so it is vital that, as very small players, they are treated fairly in a very big system. It is a requirement under EU law to offer fair, market-rate payment for small-scale solar power exports and government has decided to leave this to a market that it does not trust to supply power at a fair price. 

Nevertheless we are hopeful that there are innovative electricity supply companies who understand the importance of incentivising homeowners who want to install solar, battery storage and EV charging as we move towards a smart energy system. Barriers still need to be resolved and it is incumbent on government to remove these to encourage as thriving and competitive a market as possible, including for aggregators.”

Innovative supplier Octopus Energy have already taken steps towards meeting the requirements of the SEG with the first truly ‘smart’ export tariff offer, which includes both a simple fixed payment for all surplus power exported to the grid at a fair market rate of 5.5p/kWh, and a ‘smart’ tariff, which will enable homes with solar and battery storage that can control when they export power to the grid to potentially benefit from even higher rates because they can export at ‘peak’ times when power is more expensive.

However, while this initial offering is positive, it does have its limits. In order to benefit from Octopus Energy’s offer, you also have to be a customer on the supply side. If other suppliers follow this format, there is a risk of consumers being saddled with opaque package deals that cloak the true economics of household power use and supply. Furthermore, this offer only applies to the domestic market. Since April 2019, small-scale commercial and community energy generators have been left with no route to market.

Details released on the SEG so far are scant, so the STA is not yet able to comment in depth, however, it is expected that MCS certification or the equivalent will be a requirement to qualify for a SEG, helping to safeguard high standards in the industry.

The announcement is expected to fall short of demands to mandate a minimum price following a vigorous lobbying effort including politicians and the public alike. MPs such as Antoinette Sandbach and Douglas Ross have been particularly vocal on the matter, as have campaign group 10:10 Climate Action. Should the market fail to provide and sustain fair offers there will be immediate pressure on Government to intervene.

 

SOLAR TRADE ASSOCIATION

In February, schoolchildren from around the globe went on strike to demand urgent action on climate change. It followed stark warnings within a report from the Intergovernmental Panel on Climate Change (IPCC) stating that unprecedented measures are required within the next 12 years to limit temperature rises to 1.5°C above pre-industrial times – avoiding potentially catastrophic global impacts.

 

With the built environment estimated to account for around 40% of total UK carbon emissions1, improving the energy efficiency of our buildings must be viewed as a priority.

The Passivhaus Standard offers a proven model for minimising the energy usage of buildings via a fabric-first approach. By applying its principals with the precise design, improved predictability and outstanding thermal performance of structural insulated panels (SIPs), developers are now achieving Passivhaus Certification on projects of increasing scale and complexity.

Getting Certified

At its core, the Passivhaus Standard aims to allow the creation of buildings which require very little energy to heat or cool, whilst also providing a high level of comfort for occupants. To achieve this, it sets clear energy performance targets which a building must meet:

Primary energy demand ≤ 120 kWh/m2/yr

Space heating/cooling demand ≤ 15 kWh/m2/yr

Specific cooling load ≤ 10 W/m2

Passivhaus performance targets for cooler climate buildings

To put these figures in context, the maximum space heating demand for a Passivhaus building is around 10% of that of an average home (estimated to be 140 kWh/m2/yr 2). As such, whilst these criteria do not specifically address a building’s carbon emissions, in practice they should significantly limit emissions when compared with a property built to current Building Regulations/Standards.

To meet these criteria, all areas of the external fabric of the property typically need to be insulated to a U-value of 0.15 W/m2.K, or lower. It is also a requirement of Passivhaus that the building be fundamentally ‘thermal bridge free’. To achieve this, close attention to detailing is crucial when designing the building and installing the insulation to ensure that potential thermal bridges around openings and at junctions (especially the wall / floor) are properly addressed. In addition, air leakage rates must be no higher than 0.6 ach@50 Pa. This is typically achieved by installing an airtight layer, such as oriented strand board (OSB), and airtight tape, which is applied to seal all junctions.

High levels of airtightness within Passivhaus buildings necessitates good ventilation via means of a mechanical ventilation with heat recovery (MVHR) system. MVHR systems extract the heat from outgoing stale air and transfer it to warm incoming fresh air, further reducing the heating demand and ensuring a fresh, comfortable environment within the home.

Whilst it is possible to attain Passivhaus certification with traditional construction methods, in many cases offsite construction approaches such as SIPs can provide a simpler, faster and more adaptable solution to meeting the demanding fabric requirements.

SIPs

A typical SIP comprises an insulated core sandwiched between two layers of oriented strand board (OSB), with a jointing system that ensures excellent insulation continuity throughout the envelope, limiting repeating thermal bridging. The panels are precision cut to each project’s particular specifications in a production facility, including spaces for openings, such as windows and doors. This ensures an accurate fit, significantly reducing the need for onsite adjustments and waste. It also gives architects considerable freedom in determining the design for the property.

The panels offer excellent ‘out-of-the-box’ fabric performance with whole wall and roof U-values of 0.20 – 0.17 W/m2.K, or better. By assessing all junctions and openings within the building envelope, and carefully installing additional insulation, thermal bridges can be eliminated, and the U-values of all elements reduced to the required level.

The jointing arrangements inherent in SIPs can also support extremely airtight structures. Once an airtight membrane is fitted internally and tape is applied to junctions, the air leakage rate can be reduced to the 0.6 ach @ 50 Pa required by the Passivhaus Standard.

SIPs also provide a number of practical benefits. Their offsite production process supports greater predictability in scheduling, allowing project teams to accurately plan for panel deliveries, avoiding trade overlaps and maximising site efficiency.

The panels can be quickly installed by a small team of trained operatives with a dry construction process that is less dependent on weather conditions than other traditional approaches. When SIPs are used for both the walls and roof, the outer shell of domestic properties can often be erected in just two to three weeks. With the addition of a breather membrane to the panel exteriors, the construction is made weathertight — allowing internal fit-out to begin. The outer timber facing also provides a suitable substrate for a variety of cladding options including brick slips, render and timber cladding.

In Practice

One project to take advantage of the benefits SIPs provide is the Norwich Regeneration Company’s Rayne Park estate. The development includes a mix of private and affordable housing, with 112 of the 172 properties, earmarked for full Passivhaus Certification.

The Kingspan TEK Building System was chosen to form the envelope of many of the dwellings based on its technical specification and value offered through its offsite production process. The first phase of the development completed this March, with the Passivhaus units expected to have a heating demand of just 11 kWh/m2/yr and a primary energy requirement of 77 kWh/m2/yr.

Scalable Solution

With over 65,000 buildings now certified Passivhaus around the globe, the Standard provides a clear route to dramatically reducing the energy performance, and consequently carbon emissions, from our buildings. Offsite approaches such as SIPs provide the ideal delivery method for this standard, allowing the cost-effective construction of entire estates.

www.kingspaninsulation.co.uk

 

1 UK Green Building Council – Climate Change www.ukgbc.org/climate-change

2 Why Choose Passivhaus? Passivhaus Trust www.passivhaustrust.org.uk