The ‘Tea cosy’ effect!

Green Building Store launches new Passivhaus range

Tea cosy effect Green Building Store Passivhaus rangeLeading environmental construction products supplier Green Building Store is today (Tuesday 6th January 2009) launching an extensive range of Passivhaus products and services which it hopes will help facilitate the uptake of Passivhaus design and construction in the UK. Green Building Store’s new Passivhaus range can help the UK construction industry create buildings which use 90% less energy for space heating than standard UK buildings.

Green Building Store believes Passivhaus design offers the most effective – and cost-effective  – strategy for ‘low carbon’ construction in the UK. Passivhaus design is based on the principle that reducing heating loss to the minimum is the most cost-effective way of creating a low carbon building. Instead of complicated design and expensive bolt-on renewables, Passivhaus design relies on a simple ‘tea cosy’ effect maximising the use of super insulation and stringent airtightness. By combining this with passive solar gain and mechanical ventilation and heat recovery systems, Passivhaus design can create healthy and comfortable buildings that require minimal heating.*

Green Building Store’s Passivhaus range brings together under one roof many of Europe’s leading Passivhaus products, introducing a number of them for the first time to the UK market.

The new Passivhaus products and services include:

  • Passivhaus windows: Among the most thermally-efficient windows/ doors available in the UK, with whole U values as low as 0.68 W/m2K. Available in FSC 100% timber or timber/ fibreglass composite.
  • Pro Clima airtightness membranes and tapes: Can help buildings achieve the high levels of airtightness required for Passivhaus buildings, as well as protecting building structures from condensation, mould, rot and damp through use of ‘intelligent’ vapour checks.
  • PAUL Heat Recovery Ventilation (MVHR) systems: Heat Recovery Ventilation (also known as Mechanical Ventilation Heat Recovery) is an essential part of Passivhaus building design and helps circulate air and keeps heat in the building, through use of a heat exchanger. PAUL’s heat exchanger is one of the most efficient on the market and can offer exceptional heat recovery of up to 99%.
  • Design & Build: Green Building Store’s sister company Green Building Co. now offers a Passivhaus and ‘low carbon’ design and build service in the West Yorkshire and the North-West regions.

Green Building Store’s Passivhaus products will be showcased at this year’s Ecobuild (Stand 1833). Green Building Store Director Chris Herring will be speaking at this year’s Ecobuild on the urgent need for Passivhaus design in the UK (Ecobuild ‘road to zero carbon’ seminar  ‘Creating a Passivhaus culture’ Tuesday 3rd March 2009 10.30am).

For more information on Green Building Store’s new Passivhaus products and services go to: www.passivhausproducts.co.uk or ring: 01484 461705.

 

Notes

Green Building Store believes the UK Government’s strategy on ‘low carbon’ building needs to be urgently revised to put greater emphasis on energy efficiency, airtightness and other Passivhaus design principles and away from ‘eco-bling’ and expensive bolt-on renewables.

“We have introduced our new Passivhaus range to accelerate the adoption of Passivhaus design and construction in the UK. Passivhaus building design is proven to deliver cost-effective low carbon buildings.  It has been widely adopted in Europe and has recently had high level support from the European Parliament. The UK urgently needs to embrace the Passivhaus approach if we are to respond to the threat of climate change effectively and cost-effectively.”
Chris Herring, Director, Green Building Store

Green Building Store is a member of the AECB (sustainable building association) and actively supports its promotion of Passivhaus design standards through the CarbonLite Programme. www.carbonlite.org.uk

* Passivhaus buildings require minimal heating input, often relying on incidental gains from occupants’ body heat and cooking/ showering activities.

 

Next generation of green leaders graduate with a little help from Green Building Store

blankSix future green leaders graduate today from local learning centre and community hub, Tod College’s  Green Futures course.  

The course for 16+ year olds has been specially designed to help students develop practical skills in environmental land management, natural building, repair and reuse, energy-saving, and renewable generation schemes. The first-of-its-kind 12-month, part-time course in further education has a practical focus on green careers and has a learner-centred pedagogical approach. 

As part of the course, the six students, Georges Almond, Julija Hansen, Nate Jackson, Joy Rooney, Dick Sharp, and River Wild, all had to plan, design and present an independent project for a sustainability idea. Their projects include a community project engaging refugees in an allotment, a DIY skin care kit using natural products and local herbs, and an educational permaculture computer game.  

During the course, the students have received educational training from several partner organisations, including Green Building store. Former communications manager Chayley Collis in one of her final acts before leaving, presented to the students on Passivhaus and retrofit building. 

Taking place at the award-winning Cre8 Barn on Yorkshire Wildlife Trust’s Stirley Reserve near Castle Hill in Huddersfield, the students saw and experienced first-hand the benefits and principles of Passivhaus buildings, including Cre8 barn’s mechanical ventilation with heat recovery (MVHR) system. The Cre8 Barn was retrofitted to the EnerPHit standard, the Passivhaus standard for retrofit, by Green Building Store’s construction team in 2015. 

Passivhaus buildings can cut the energy needed for heating by 90% compared to the UK’s typical uninsulated housing stock. The Green Futures students were taught the principles of super-insulation, airtightness, continuity of insulation (ensuring that insulation wraps around the building like a tea cosy), how to utilise the energy from the sun, as well as ‘heat recovery ventilation’, which is an essential component of Passivhaus buildings. MVHR systems work by warming up the fresh air coming into a building with the heat of the outgoing air, helping to conserve the energy inside the building.  

Jill Delaney, People Director at Green Building Store, commented:  

“Educating the next generation on how we can build more sustainably is crucial—finding those minds who are inspired and passionate about building a better future has never been so important, especially if the UK is truly to lead the way in reducing our impact on the climate, tackling fuel poverty and creating energy security. We’re delighted to see the next generation of green visionaries graduate today. 

Green Building Store is committed to employing the best talent, and if we can help inspire future green builders and retrofitters, then we know we can continue our work into a future that will need such committed and imaginative students as those from the Climate Challenge College.” 

The Green Futures course hopes to inspire students to find careers in areas such as natural building, growing, sustainable products, consulting, environmental engineering, horticultural therapy, renewable energy, and retrofitting. 

Chelsie Naylor, Programme Leader for the Green Futures course, commented:  

“It is brilliant for our students to learn more from companies like Green Building Store about retrofitting and the Passivhaus methodology and to experience the warmth and comfort of a Passivhaus building first hand. The support of our partners makes today’s graduation possible.” 

One of the students, when visiting the barn, even described the warmth and comfort of being inside the Cre8 Barn as “like being in a hug”. 

Stephanie Turner, Inspiring People Officer at Yorkshire Wildlife Trust, added: 

“We’re very proud of our award-winning Cre8 Barn and pleased to share such a brilliant retrofit exemplar with the students during their course, thanks to funding from Veolia Environmental Trust. Buildings designed to the EnerPHit (Passivhaus retrofit) standard are more relaxed and receptive places to work, teach and learn thanks to their greater comfort and energy efficiency.” 

The green job market is growing rapidly, and as well as providing training, Green Building Store staff also spoke to the students about potential job opportunities in the company and the wider Efficient Building Solutions businesses.  

For more information on the current vacancies at Green Building Store, click here.

Comfortable, cheap and saving the planet

 

Dated: 11/10/2010

Link to future passiv filmPassivhaus (translated as ‘passive house’ in English) is an approach to designing ultra low energy homes and buildings that is beginning to sweep the nation. Today (Tuesday 12th October 2010) Green Building Store launches ‘Future Passiv’ a short 10 minute documentary which makes the case for Passivhaus as a standard for all UK new builds – and even for the refurbishment of existing buildings.

Presented by eco broadcaster Penney Poyzer (BBC2’s “No Waste like Home”), ‘Future Passiv’ features Green Building Store’s Denby Dale Passivhaus project in West Yorkshire and outlines the many advantages of the Passivhaus approach to low energy building. As well as offering incredibly cheap heating bills (heating costs for the Denby Dale Passivhaus are expected to be around £75 per year), Passivhaus buildings can also make a significant contribution to tackling climate change, as well as being very comfortable to live in. ‘Future Passiv’ includes interviews with the owners of the Denby Dale Passivhaus and looks at the way in which Passivhaus design is really beginning to take off in the UK including housing associations, schools, offices and community centres as well as private homes.

Passivhaus design can create buildings which use 90% less energy for space heating than standard UK buildings. Based on the principle that reducing heating loss to the minimum is the most cost-effective way of creating a low carbon building, Passivhaus design relies on a simple ‘tea cosy’ effect maximising the use of super insulation and stringent airtightness. By combining this with passive solar gain and mechanical ventilation and heat recovery (MVHR) systems, Passivhaus design can create healthy and comfortable buildings that require minimal heating.

Penney Poyzer said,

“Passivhaus is a philosophy in itself. It is a mix of applied physics, common sense and practical wisdom and it can be applied to any type of building, not just housing. It can be applied to new build or retrofit. It is a proven technique which shows that it is entirely practical and feasible to aim for buildings that use 90% less energy than typical UK housing stock. If the UK is to achieve massive reductions in carbon then it is essential that we tackle the built environment. Across Europe, buildings account for 60% of carbon emissions. I believe that Passivhaus can slash those emissions now.”

The ‘Future Passiv’ documentary is part of a larger film ‘Passivhaus low energy building in the UK’  project which includes a 60 minute technical film for building professionals, covering all stages of construction of the Denby Dale Passivhaus  – the UK’s first Passivhaus to be built using traditional British cavity wall construction methods. With a Foreword by Jonathon Porritt, the film sets out to offer the UK construction industry a template for building ultra low energy Passivhaus buildings using construction methods and materials familiar to UK builders and designers.

The Future Passiv documentary and Denby Dale Passivhaus technical film are freely available to view at Green Building Store’s website www.greenbuildingstore.co.uk. A free technical briefing (40 page pdf) is also available to those registering at: www.greenbuildingstore.co.uk/denbydalehouse

‘Future Passiv’ and ‘Passivhaus low energy building in the UK’ were filmed and edited by student film-makers and were made possible thanks to the kind sponsorship of Kirklees Council.

Notes for the Editor

Green Building Store

Green Building Store is a specialist manufacturer/ supplier sustainable building products as well as supplying a range of Passivhaus services including Passivhaus products, training, consultancy and construction. It won a Queen’s Award for Enterprise: Sustainable Development 2009 for its “pioneering approach to sustainability” and for delivering “cutting edge sustainable products to the market”.

Green Building Store, Heath House Mill, Heath House Lane, Golcar, Huddersfield HD7 4JW
Tel: 01484 461705; Fax: 01484 653765; [email protected]
www.greenbuildingstore.co.uk

Denby Dale Passivhaus

The Denby Dale Passivhaus project in West Yorkshire is one of the first certified Passivhaus homes in the UK and is the first to be built in the British vernacular style, using a cavity wall construction. The house will require minimal heating and will use 90% less energy for space heating than the UK average. Built to a tight budget of £141K, the 118m2 three-bed detached house aims to be an exemplar of how Passivhaus construction can be achieved inexpensively by a small, skilled construction team. The project was led and managed by Green Building Company (Green Building Store’s construction division).

Key features

* One of the first certified Passivhaus homes in the UK
* First certified Passivhaus built with cavity wall construction in UK
* £141K basic build costs
* 118m2 three-bed detached house
* Airtightness: 0.33 ach @ 50 Pa
* Space heating needs: under 15 kWh/m2/annum
* Minimal heating – using 90% less energy for space heating than the UK average
* Heating costs of around £75 per year.
* Subject of the popular ‘Passivhaus Diaries’ blog
* Shortlisted for RIBA Yorkshire White Rose Awards – Sustainability Award (results announced 26/11/10)
* Shortlisted for Sustainability Awards – Sustainable Housing Project of the Year (results announced 30/11/10)

More information at: www.greenbuildingstore.co.uk/denbydalehouse

Jonathon Porritt

Jonathon Porritt, Co-Founder of Forum for the Future, is an eminent writer, broadcaster and commentator on sustainable development.  Established in 1996, Forum for the Future is now the UK’s leading sustainable development charity, with 70 staff and over 100 partner organisations, including some of the world’s leading companies.
In addition, he is Co-Director of The Prince of Wales’s Business and Sustainability Programme which runs Seminars for senior executives around the world. He is a Non-Executive Director of Wessex Water, and of Willmott Dixon Holdings.  He is a Trustee of the Ashden Awards for Sustainable Energy, and is involved in the work of many NGOs and charities as Patron, Chair or Special Adviser.
www.jonathonporritt.com
www.forumforthefuture.org

Penney Poyzer

Penney Poyzer was recently hailed as one of 100 British women of the last century who have changed the world. She is an acknowledged expert across a broad church of green issues. She is an author, broadcaster and campaigner. She presented BBC2’s ground-breaking series “No Waste like Home” which has been seen in 27 countries.
She is patron of a number of green charities and was recently appointed as an expert to the EU. She is co-creator of the Nottingham ecohome, the UK’s first radical eco retrofit of a hard to treat home. Now in its eleventh year, Penney and her green architect husband Gil Schalom, are acknowledged as pioneers of the eco retrofit movement. Penney is an advisor and consultant to a wide range of organisations.
www.penneypoyzer.com

Kirkees Council

The production of ‘Future Passiv’ was made possible thanks to the kind sponsorship of Kirklees Council. Mehboob Khan, Leader of Kirklees Council said:

“Kirklees Council is at the forefront of local government efforts to reduce CO2 emissions from buildings and we are delighted to have the low energy exemplar Denby Dale Passivhaus project within the Kirklees area. We are fortunate to be able to benefit from Green Building Store’s expertise in this exciting new approach to low energy construction and we hope that the Denby Dale Passivhaus will offer a template for the construction industry to help deal with the urgent problems of climate change and fuel poverty.”

 

How to build or retrofit your own Passivhaus

Denby Dale Passivhaus

Following BBC Look North’s coverage of Green Building Store’s Denby Dale Passivhaus today (Thursday 20th May 2010), Green Building Store has created some advice pages on its website for individuals interested in building their own Passivhaus or refurbishing their existing home using the passive house approach. Passivhaus design can help create buildings which use 90% less energy for space heating than standard UK buildings. Green Building Store believes the passive house methodology offers the most effective – and cost-effective  – strategy for ‘low carbon’ construction in the UK. Passivhaus design is based on the principle that reducing heating loss to the minimum is the most cost-effective way of creating a low carbon building. Instead of complicated design and expensive bolt-on renewables, Passivhaus design relies on a simple ‘tea cosy’ effect maximising the use of super insulation and stringent airtightness. By combining this with passive solar gain and mechanical ventilation and heat recovery systems, Passivhaus design can create healthy and comfortable buildings that require minimal heating.

The Denby Dale Passivhaus has anticipated space heating costs of £75 a year and was built by Green Building Store to a tight budget of £141K. It is the first Passivhaus built using traditional cavity wall construction in the UK. Information on the Denby Dale Passivhaus is available at: www.greenbuildingstore.co.uk/denbydalehouse

Green Building Store’s new Passivhaus advice sections cover everything from finding land, getting planning permission and finding an architect to sourcing Passivhaus products.Passivhaus design can be applied both to new build and refurbishment projects.

Over the next few weeks the owners of the Denby Dale Passivhaus will also be launching a blog on the Green Building Store website,  which will chronicle their experience of living in a Passivhaus and explain what it is like livng with MVHR ventilation and ultra low gas bills!

For more information, go to: www.greenbuildingstore.co.uk/page–living-in-the-denby-dale-passivhaus-blog.html

Green Building Store offers a range of Passivhaus products and services including: building products, design and build and training. For more information, please ring the Green Building Store team on 01484 461705 or email: [email protected]

Passivhaus offers hope for Copenhagen talks

Denby Dale Passivhaus - exterior

While world leaders grapple with setting binding targets for CO2 emissions at the Copenhagen Climate talks next week and scientists call for up to 90% cuts, a small building project in West Yorkshire is demonstrating how these tough targets could easily be met by the majority of UK homes and buildings. The Denby Dale Passivhaus, currently under construction, will require minimal heating and will use 90% less energy to heat1 than the UK standard. Passivhaus design is already popular in continental Europe but is still relatively unknown in the UK. The Denby Dale Passivhaus will be one of the first certified Passivhaus buildings in the UK and is expected to be the first to be built in the UK using traditional cavity wall construction.

The Denby Dale Passivhaus is currently being built for private clients in the village of Denby Dale, West Yorkshire by Green Building Store‘s construction division  – Green Building Company. Passivhaus buildings can achieve 90% cuts in heating bills for their occupants, with the heat generated from the sun through windows, occupants’ (and pets’!) body heat, cooking and showering activities often all that is needed to warm a Passivhaus home.  Built to a tight budget of £140K, the 118m2 three-bed detached house aims to be an exemplar of how Passivhaus construction can be achieved inexpensively by a small, skilled construction team.

Passivhaus design was first developed in Germany almost 20 years ago and is based on well researched and proven building physics. Instead of complicated design and expensive bolt-on renewables, Passivhaus design relies on a simple ‘tea cosy’ effect of maximising the use of super insulation and stringent levels of airtightness. By combining this with optimum levels of ‘passive’ solar gain and mechanical ventilation and heat recovery systems, Passivhaus design can create healthy and comfortable buildings that require minimal heating.

Buildings (in construction and use) are responsible for a massive 50% of all UK CO2 emissions2 but this is also the sector where radical action is most easily achievable, as the Denby Dale Passivhaus demonstrates. Building and retrofitting buildings to Passivhaus standards would also offer politicians a relatively  ‘easy win’ as few voters would object to cosier homes and vastly reduced fuel bills, as opposed to the radical changes needed in the more controversial transport and aviation sectors. Unlike the overwhelming majority of buildings currently being constructed, the energy consumption of Passivhaus buildings is carefully modelled and monitored,  providing politicians with concrete evidence of reduction of CO2 emissions. Unless low energy buildings are properly monitored and measured, politicians will never know, and would not be able to say with any confidence, whether CO2 targets in the building sector are being met.

Green Building Store believes Passivhaus design offers the most effective (and cost-effective) way the construction industry can respond to the urgent threat posed by climate change. Bill Butcher, Green Building Store Director said: “The timescale for action on climate change is too short to ‘reinvent the wheel’ or experiment with untested low energy construction approaches. We need to work with effective and proven Passivhaus approaches which focus on retaining heat within buildings. We believe that investing in the energy efficiency of the building fabric is a much more  cost-effective way of reducing CO2 emissions than the current obsession with bolt-on micro-renewables.”

Blogs on the construction of the Denby Dale Passivhaus (The Passivhaus Diaries) can be found at:  www.greenbuildingstore.co.uk/denbydalehouse

Notes for the Editor

References

1. Passivhaus houses use around 90% less energy for space heating than the average UK home (15 kWh/m2/annum, as opposed to 139 kWh/m2/annum for average dwelling stock).

Average UK dwelling stock uses energy at rate of 278 kWh/m2/year with space heating making up 50% of all domestic energy use.

Source: DTI Digest of UK Energy Statistics 2004 and AECB Yearbook – The Sustainable Building Guide – 2006/7

2. Aviation figures not included in calculation.
Source:  AECB Yearbook – The Sustainable Building Guide 2006/7

Background briefings

Passivhaus in the UK

Green Building Store believes that urgent action is needed to integrate Passivhaus standards into UK targets for low and Zero Carbon buildings in the UK, through the Energy elements of Code for Sustainable Homes and upcoming revisions of the Building Regulations.  According to Bill Butcher, Green Building Store Director and project leader at the Denby Dale Passivhaus “We believe that the Code for Sustainable Homes in its current form (and in particular SAP 2005) is proving an obstacle to the introduction of Passivhaus buildings in the UK, as it is not sophisticated enough to accurately predict the actual energy use of Passivhaus and low energy homes. We would like CSH to replace SAP with the much more accurate Passivhaus Planning Package (PHPP) as its energy calculation methodology”.

For more information on the relationship between Passivhaus and Code for Sustainable Homes, go to: www.greenbuildingstore.co.uk

Support for Passivhaus design

Green Building Store is among a growing number of organisations that are convinced that Passivhaus building design is the direction that the UK construction industry (and the world) needs to be moving in. Tried and tested in over 10,000 buildings (homes, schools, factories etc)  in continental Europe over the last 20 years, Passivhaus design has also recently gained some heavyweight support. On January 31 2008 the European Parliament passed a resolution in which it called on the Commission “to propose a binding requirement that all new buildings needing to be heated and/or cooled be constructed to passive house or equivalent non-residential standards from 2011 onwards”. The AECB – also known as the sustainable building association – is also a vigorous supporter in the UK and offers a comprehensive training programme in Passivhaus design through its CarbonLite Programme (www.aecb.net).

Projected cuts in emissions

The AECB has calculated that if the UK adopted its standards (based on Passivhaus principles) wholesale then in 2050 domestic buildings, instead of producing 33 million tonnes of carbon dioxide each year would only produce 3.3 million tonnes. (Source: AECB Yearbook – The Sustainable Building Guide 2006/7).

About Green Building Store

Established in 1995, Green Building Store is a specialist manufacturer/ supplier of: FSC timber windows and doors; water-efficient toilets and sanitaryware; Passivhaus products; and natural building materials. Founded by three experienced building professionals Bill Butcher, Chris Herring and Steve Slator, the company grew out of their frustration with the poor availability of ecological building products. The company is committed to doing all it can to help tackle climate change and to act as a centre of excellence, championing best practice in low carbon and sustainable construction. Green Building Store is based in Heath House Mill, Bolster Moor, Golcar in the hills above Huddersfield.
www.greenbuildingstore.co.uk, Tel: 01484 461705

About Denby Dale Passivhaus

Latest blogs and information on the Denby Dale Passivhaus can be found at: www.greenbuildingstore.co.uk/denbydalehouse

Bill Butcher, project leader of the Denby Dale Passivhaus will be taking part in the Big Debate ‘ Is Passivhaus right for the UK’ during the Sustainability Now online conference on Wednesday 9th December 2009.

Queen’s Award ceremony

 

Green Building Store receiving the Queens Award for Sustainable Development 2009

Green Building Store receiving the Queens Award for Sustainable Development 2009

Green Building Store is celebrating its Queen’s Award for Enterprise: Sustainable Development 2009 at a ceremony today (Wednesday October 7th 2009) at its HQ in Bolster Moor, Huddersfield. The Lord Lieutenant of West Yorkshire, Dr Ingrid Roscoe will be presenting the award to Green Building Store directors and staff at a ceremony which will also be attended by the Mayoress of Kirklees, Julie Stewart-Turner and Colne Valley MP Kali Mountford.

The event will mark the culmination of several exciting developments at Green Building Store including the official launch of Denby Dale Passivhaus low carbon project in West Yorkshire.The Denby Dale Passivhaus is currently being built by Green Building Store’s construction division  – Green Building Company – and will be one of the first certified Passivhaus buildings in the UK and is expected to be the first to use traditional UK cavity wall construction. The Denby Dale Passivhaus will require minimal heating and will use 90% less energy for space heating than the UK average (15 kWh/m2/annum, as opposed to 150 kWh/m2/annum).  Built to a tight budget of £140K, the 118m2 three-bed detached house aims to be an exemplar of how Passivhaus construction can be achieved inexpensively by a small, skilled construction team.Passivhaus design was first developed in Germany around 20 years ago and is popular in continental Europe but is still largely unknown in the UK. Instead of complicated design and expensive bolt-on renewables, Passivhaus design relies on a simple ‘tea cosy’ effect of maximising the use of super insulation and stringent airtightness. By combining this with passive solar gain and mechanical ventilation and heat recovery systems, Passivhaus design can create healthy and comfortable buildings that require minimal heating.  Green Building Store believes Passivhaus design offers the most effective way the construction industry can respond to the urgent threat posed by climate change and is committed to providing the products and expertise to help facilitate its rapid adoption in the UK.

Green Building Store won its Queen’s Award for Enterprise: Sustainable Development 2009 earlier this year but will be receiving the award itself at a special ceremony and celebration today at its offices and workshops in the company of its 30 strong worksforce. The Queen’s Award recognises the role played by Green Building Store in developing the market for sustainable building products in the UK and its ‘pioneering approach to sustainability’. In addition to its new Passivhaus range, the company has pioneered sustainable practices in window manufacture with its Ecoplus range of timber windows and doors (made at its Heath House Mill workshops), and also offers leading edge water-saving products.Over the next few months Green Building Store will be launchng a DVD for architects and builders showing the detailed Passivhaus building techniques used to construct the Denby Dale Passivhaus. Regular fortnightly blogs of the construction of the Denby Dale Passivhaus are also being followed by BUILDING magazine (The Passivhaus Diaries) and can be found at:  www.greenbuildingstore.co.uk/denbydalehouse

For more information on Green Building Store Tel: 01484 461705 or go to www.greenbuildingstore.co.uk

Mill building office radical retrofit: Heating & ventilation

Our office retrofit scheme is nearing completion and the MVHR team is eagerly awaiting being able to move into its new cosy, efficient and well-ventilated offices. In this blog, we outline the heating and ventilation strategies for the retrofit.

MVHR mechanical ventilation with heat recovery

Unsurprisingly, our MVHR team undertook the MVHR designs for the new offices! Two separate MVHR systems have been designed for the space:  one for the open-plan office space and one for the conference room, kitchen, bathroom and hallway areas.  Two units were needed because of the variable potential occupancy rates.

 

Mill office radical retrofit MVHR design 1

 

The MVHR team has worked on new configurations of where supply and extract air valves go, in response to the open-plan space and drawing on the latest understanding of how to minimise the risk of infection from airborne diseases, taking advantage of ‘displacement ventilation’.

 

Displacement ventilation

Displacement ventilation essentially means supplying air slowly at low level and extracting at high level. The supply air might be supplied at ground floor level and the stale air from the room might be extracted from ceiling height. It is a ventilation strategy that also benefits from the fact that ‘hot air rises’ through convection.

Displacement ventilation is useful for open plan rooms where supply and extract air valves are located in the same room. If both supply and extract valves are located in the ceiling area there would be a danger that fresh the air will just travel along the ceiling and be extracted without circulating through the room – effectively meaning that the ventilation to the room is being ‘short-circuited’ and is not going to where it is needed. Displacement ventilation has also been cited as having a useful role to play in reducing the risk of transmission of airborne illnesses, especially in office settings minimising the horizonal circulation of air by mainly moving air vertically from the ground to the ceiling. Our friend Paul Smith at Greengauge has been very active in researching the positive benefits of displacement ventilation for minimising airborne infection rates, especially in office situations.

This is the first time that our MVHR team has used ‘displacement ventilation’ techniques as it is not usually the way we model airflows for private domestic properties. However, it seems a very useful approach for office/ open plan spaces and we would definitely consider replicating this approach when working on similar projects.

 

Open-plan office space

Mill office radical retrofit MVHR design 2

 

A Zehnder ComfoAir Q600 MVHR unit will be used for the open-plan office space.

The supply air ventilation has been designed to be placed at a low ground floor level and the extract valves will be placed at ceiling level as part of the displacement ventilation design.

Lindab CHA air diffuser

Lindab CHA air diffuser

The air valves for the supply ventilation are a new design to us (Lindab CHA) and are located at floor level. The CHA is described as a ‘semi-circular perforated displacement diffuser for installation against a wall or column’. We need to be careful with the location of these diffusers as we don’t want to create a draught near people’s feet, even though the fresh supply air is at room temperature, having passed through the MVHR heat exchanger.

A note on air valves and commissioning

As the CHA air valve is new to us, we are having to work out a few things such as to how to moderate the airflow through it, which is especially important during the MVHR commissioning process. When commissioning an MVHR system we need to adjust all the air valves in the MVHR system to release differing amounts of air depending on where in the system they are. In general, the air valves early on in the ducting system will need to be most closed to restrict airflow through, while the air valves at the end of the system would tend to be the most open. This adjustment of the air valves ensures that air passes through the ducting sufficiently to reach all air valves and is carefully modelled in airflow calculations.

 

Conference room, kitchen, bathroom & hallway

A Zehnder ComfoAir Q600 MVHR unit will be used for the second zone of the office, with the unit being located in the Conference room.

We have used a mixture of displacement and our normal ventilation strategies. The conference room has some of the CHA supply air valves at floor level (but not everywhere as we can’t put one in that position because of a radiator). There are more separated rooms in this section of the office and so our more normal approach of locating supply air valves on the walls and extract valves in wet room ceilings (kitchen and bathroom), with air passing through door undercuts is also part of the strategy. Nevertheless, the conference room does have some displacement ventilation approaches, with floor level supply and ceiling level extraction.

 

Mill office radical retrofit MVHR design 3CO2 sensors

As the building will have variable occupancy, with sometimes 1-3 staff and sometimes 20+, we are installing CO2 sensors to help ensure the MVHR system is delivering the correct volume of air changes. The MVHR CO2 sensors are connected to the MVHR  units and will set the fan speeds according to occupancy and CO2 levels in the building. The MVHR system will go into ‘Boost’ mode when the CO2 sensors pick up that occupancy is high.

Ducting

As is our preference on systems which require such a high air flow rate, we have designed using the rigid spiral wound ducting system. As the ducting is fully exposed, this option provides better aesthetics than what a plastic radial system would offer.

Air source heat pump

A heating system for the office is being designed by our sister company Green Building Renewables and is a 8.5 kW Mitsubishi EcoDan air source heat pump (ASHP) which will supply heat to the building via wall mounted radiators.  The ASHP fan unit will be installed outside on a concrete base, with a temperature thermostat and control installed in a central location inside.

Heat pump efficiency

The heat pump’s Seasonal Co-efficient Of Performance (SCOP) is 4.79. This means that on average over a year for every 1 Kilowatt of electricity the system uses it will output 4 Kilowatts of heat. Ignoring primary energy for a second, this compares very favorably with gas boilers which have an efficiency of around 96%. Crucially the national electricity grid is now, on average, delivering less CO2 emissions per kWh delivered than gas, so it’s already more sustainable to install a heat pump. The electricity grid is getting greener every year as new offshore wind farms are brought online.

A solution for hot water

We won’t be needing a hot water cylinder because the office space has minimal hot water demand and the internal gains from the cylinder and pipework would contribute to overheating in summer. Instead, we are installing a 15 litre capacity under sink immersion heater. This will supply enough water to the kitchen and 3 wash hand basins in the WCs. We are installing a shower for colleagues who cycle to the office but this is an electric shower so provides hot water on demand for the occasional use that it will get.

Sizing the radiators

Green Building Renewables has calculated the anticipated heat outputs for each room which enabled us to size the radiators accordingly. We have gone with ‘triple’ radiators which are 50% wider than standard radiators. These allow us to fit the correctly-sized emitter without taking up too much wall space. Heat pumps in retrofit typically need larger radiators because heat pump system run at a lower circulation temperature of 35°C, whereas a gas boiler will run at 60°C.

 

Bill ButcherAdam Harper, Green Building Companyblank

Rikki Jarnot, MVHR Design Manager

Adam Harper Construction Manager

Bill Butcher, Director

Green Building Store

Mill office radical retrofit

 

Green Building Store’s building team has undertaken a cost-effective and pragmatic radical retrofit of warehouse space into a cosy and energy efficient office space. The office space will accommodate up to 26 of Green Building Store’s own MVHR heat recovery ventilation staff.

Mill office radical retrofit: A ‘box within the box’

Office overspill

Green Building Store is outgrowing its existing office space at Heath House Mill (in Bolster Moor on the hills above Huddersfield), Fortunately, the Heath House Mill former woollen mill complex where we’re based does have some spare warehouse units that we can spill over into.

However, there are two challenges with this: we only rent the space and the space tends to be very basic, so to create office space will require investment that our landlord would not be prepared to undertake. We managed to negotiate a solution whereby our building team undertakes a retrofit of one of the former mill’s warehouse spaces in exchange for the landlord keeping our rent at the warehouse levels going forward (as opposed to a higher office rent level).

Pragmatic low-cost approach

We have therefore decided to undertake a cost-effective and pragmatic radical retrofit of 200m2 of groundfloor warehouse space (Unit 4 of Heath House Mill) into a cosy and energy efficient office space for up to 26 MVHR staff. Unit 4 has a separate industrial unit above, so our retrofit is just dealing with the ground floor.  Having another unit above gave rise to two particular issues, fire separation and noise transmission, both of which require careful thought, design and installation.

Strategy

Heath House Mill retrofit

The warehouse building was probably built around 1900 with stone outer leaf and brick inner leaf, with some rubble fill between. Effectively, we would therefore treat the wall as a solid wall. We decided that the easiest retrofit solution for this space was to replicate our retrofit strategy at the Cre8 Barn at Stirley Community Farm by creating a timber frame ‘box within a box’. This approach makes it easier to deliver the airtightness strategy and to minimize thermal bridging, without costly IWI solutions. As at Stirley Farm, it is important to have a ventilated cavity between the outer stone wall and the inner timber frame, so we will be inserting 60 X  75mm diameter louvered vents to the external walls at intervals of approximately 2.4m  Between the brickwork and the timber frame breather membrane we have a 50mm ventilated cavity to allow air movement.

Modelling and moisture mitigation

For once, we haven’t modelled the retrofit in PHPP or WUFI but are just going on our experience from the Stirley Farm project.  However, we may require an SBEM model for Building Control which will give us a benchmark as to the level of energy improvement. Though, like SAP, SBEM is not as detailed as PHPP. We know that the ‘box within a box’ approach we have chosen has worked well at Stirley Farm and has had moisture sensors monitoring it, so we are just replicating the approach just in a less exposed hillside location.

Airtightness strategy for ceiling and external walls

Whilst there is an industrial unit above our space, we know that it is very leaky. Therefore for the ceiling, we used Constavap 2.3 taped with Tescon Vana at the joints which we have installed over the top of ceiling joists in order to create a 100mm depth service zone between the top and bottom of the joists. The advantage of this is that we have an airtightness layer that doesn’t have any service penetrations going through it.

The walls have an 18mm OSB layer over the timber studs which has a reasonably good level of airtightness (though in hindsight we would have been better using Constivap under the plasterboard). The OSB board joints are taped and where the OSB meets the floor it is taped to the smooth concrete surface. This gives us a reasonably good ‘airtight box’.

Timber frame walls & ceiling

Timber frame panels at mill office retrofitExternal Walls U-Value 0.148 W/m2K

  • Timber stud walls at mill office retrofit500mmm solid wall, stone outer and brick inner
  • 50mm vented cavity with vents to the outside
  • Pro Clima Fronta Solitex WA breather membrane taped at joints with Tescon Vana
  • 140mm timber stud, filled with 140mm Knauf Frametherm 35 mineral wool insulation
  • 18mm OSB taped at joists with Tesco Vana
  • 62.5mm PU laminated plasterboard
  • Plaster skim finish

Surfaced fixed dado trunking for power and data to desks

 

Ceiling U-value 0.158 W/m2K

  • Wall ceiling detail at mill office retrofitExisting timber floor structure above
  • 100 x 50mm timber structure @400mm centres
  • 240mm Knauf FactoryClad Roll 40 mineral wool insulation 0.040W/mK for thermal and acoustic insulation
  • Pro Clima Constivap VCL, taped at joists with Tesco Vana
  • 2 layers 12.5mm fire-rated plasterboard, staggered joints
  • Plaster skim finish

Lights and MVHR ducting surface mounted on ceiling.

 

In our next blogs, we will look at floor, window, ventilation and heating strategies for the retrofit.

 

Bill Butcher, Director & Adam Harper Construction Manager, Green Building Store

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Adam Harper, Green Building Company

Room-by-room DIY retrofit

Room by room DIY retrofit project

An unassuming detached house in Chorley Lancashire has been transformed steadily over 4+ years into an eco exemplar retrofit project, thanks to the steady DIY efforts of its occupants. Diana & John Holland have undertaken a methodical room by room retrofit of the house, following advice from eco building consultant Eric Fewster at ColdProof UK, who developed a whole house plan for the retrofit. All of the retrofit work has been undertaken by the Hollands themselves, with guidance and support from Eric Fewster along the way and the involvement of local builders, electricians, plumbers and plasterers when needed.

Green Building Store supplied the triple glazed timber windows and doors and MVHR system for the project, as well as offering some consultancy advice at the outset of the project.

Inspiration

The Hollands were inspired to undertake the retrofit to reduce the carbon emissions from their home.

Diana Holland commented: “We face a climate emergency and we are very scared for the future of our children and grandchildren, but turning that fear into action on the things over which we have control has given us hope.  We continue to reduce our carbon emissions as we progress with our retrofit and have the bonus of creating an extremely comfortable home.   At the start the challenge seemed overwhelming but nibbling away at it bit by bit, room by room has made it manageable.  We feel very lucky to have had the time and resources to be able to carry it out.”

Design

The home is a detached house built in 1991 with cavity wall construction with ‘dot and dab’ plasterboard internally.

The Hollands started improving the house in by installing solar thermal and solar PV systems on the roof between 2006-10. Diana  commented: “We started the wrong way around by installing renewables and ways to generate energy, instead of thinking of fabric first options to minimise energy use in the first place.”

After a visit by Green Building Store Director Bill Butcher in 2013 the Hollands realized that they had to take more drastic action to improve the energy efficiency of their home by undertaking an energy efficient retrofit, including removal of plasterboard and addition of internal wall insulation and airtightness measures.

Eric Fewster subsequently helped draw up a whole house plan after modelling the house in Passivhaus Planning Package. This gave a strategic direction to the overall project. Eric also offered practical step-by step advice as to how the Hollands could undertake the retrofit on a room-by-room basis.

The Room-by-Room approach

Undertaking the retrofit themselves on a room-by-room basis was a practical and affordable way of making it happen, helping to spread the cost over several years.

Diana commented: “This was the only way we could afford to do the retrofit and it meant that we didn’t have to move out. Another positive has been that the mess was also only confined to one room at a time.”

The Hollands started out on the utility room as a practice run. They hacked off the dot and dab plasterboard and installed 140 mm wood fibre internal wall insulation (IWI) with Intello membrane added on top as the airtightness layer. Green Building Store’s triple glazed timber windows were installed mostly on a room by room basis as well. with the IWI wrapping the frame to help reduce thermal bridging.

As they have moved through the rooms in the house over the last few years they have gained in confidence with their retrofit skills. The retrofit has involved mainly wood-working, screwing the timber insulation into the walls and then adding timber batons for service voids.  John  Holland was already a competent amateur carpenter so has been able to build on that for the project.

The Hollands have tried as far as possible to re-use materials during the retrofit. When they retrofitted the kitchen they managed to remove and re-instate their existing kitchen units, which had, coincidentally, been made out of reclaimed timber from a ship-yard. They replaced the conservatory with a garden room and managed to re-use some French Doors from another room for that. The floor in the garden room is reclaimed wood from a school gymnasium.

By the summer of 2020 the Hollands have only got 2 more rooms to retrofit before the project will be completed. The bathroom is one of the last rooms to go because it is potentially expensive as it could involve replacing the bathroom suite. Insulating the ground floor has been missed out of the retrofit, so far, as it its very challenging and would involve substantial disruption, including removing and re-installing an oak floor. By not being able to tackle the floor the project will miss out on the chance to go for EnerPHit (Passivhaus retrofit) certification but it feels just a step too far for the Hollands after their epic retrofit efforts.

The Hollands are already feeling the benefit of the retrofit: “The retrofit has made a huge difference already and the house feels cosy and comfortable.”

Joined up thinking

By doing the retrofit on a room-by-room basis the Hollands have also needed to be aware of avoid ‘unintended consequences’. For example, with some rooms insulated and others not there could have potentially been a danger of condensation and mould growth in the uninsulated rooms, which would have been acting as ‘thermal bridges’ for moisture-laden heat from the insulated rooms. Fortunately, the Hollands had the foresight to install an MVHR system for ventilation in the middle of the retrofit work which has helped keep the air fresh and avoided any mould and condensation issues.

Detail to create a continuous airtightness barrier from room to room in energy efficient retrofit projectAnother important consideration was the need to ensure that the insulation and airtightness strategies continuous between the separate rooms. The whole house plan developed by Eric Fewster was essential for this, knowing that every element of the retrofit was contributing to the whole. For example, cutting back the ceiling in the downstairs rooms to allow IWI to be fitted between the joists and up to the floor of the room above. Then covering the IWI with Intello with enough spare to pull through to the upstairs room when the  floor is cut back and the IWI is fitted.

Triple glazed timber windows & doors

The Hollands chose triple glazed timber windows from Green Building Store, which have been installed in four phases as the retrofit has progressed. The project has included Green Building Store’s former Ecoplus3 range and more recent PERFORMANCE triple glazed range.

Diana Holland commented: “The windows and doors are fabulous and they feel very warm. There are no draughts or down-draughts coming from the windows and we get no internal condensation – only external. The noise reduction is very good too.

We like the way you really get looked after by the Green Building Store team throughout the process. There have been a small number of snagging issues but they’ve always been dealt with by the aftersales team. Over the long process of the retrofit we really feel like we’ve got to know the Green Building Store team – from Jason the surveyor who comes to measure the windows to Chris and the fitting team and everyone in the office.”

MVHR heat recovery ventilation

Green Building Store supplied and designed the MVHR heat recovery ventilation system at the project. The system will be finally commissioned when all the retrofit work has been completed.

Diana commented:

“The MVHR system is really good. We have constant fresh air inside and it has helped prevent any condensation issues while the house is still half-completed. The MVHR system is also very quiet – it is located in the ultility room and we only ever hear it when we are in there or when we need to boost the system after cooking.”

Case study 2020

More information

Eric Fewster, ColdProof  www.coldproof.co.uk/

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