Tag: sustainable design

  • HPH169 : Embracing contemporary vernacular design – with Clare Nash

    HPH169 : Embracing contemporary vernacular design – with Clare Nash

    Clare Nash from Clare Nash Architecture talks about various responses by small developers in the UK and abroad to the challenges of creating modern communities through better design.

    Interview with Clare Nash

    Clare Nash set up Clare Nash Architecture six years ago. The team operate differently to other architects, working remotely or in co-working spaces and meeting up once a week. Her book, Contemporary Vernacular Design, How British Housing can Rediscover its Soul, naturally followed on from her Masters thesis where she researched the uses of vernacular materials and technologies in modern, sustainable housing in the UK and abroad.

    In the past, houses were inherently green

    Clare says, “Vernacular [design], I think, doesn’t really exist anymore, apart from in developing countries where people are literally just self-building.” Buildings used to be sustainable and varied in their design, using local materials and low energy out of necessity. She adds, “We seem to have lost all these really good ideas in modern housing design.”

    In the UK, there are a few exceptions including Ashley Vale where a group of self-builders actually got hands-on and developed such a strong community that others really want to live there.

    Contemporary vernacular design is a hybrid of old and new

    Clare likens contemporary vernacular design to being a mixture of the best of the old and the best of the new. She cites an architectural ‘taste test’ that was carried out in Holland, where members of the public, architects and design professionals all found this ‘third way’ preferable to super modern or a pastiche of the old.

    The residents Clare interviewed in Europe abroad unanimously liked modern homes, whereas she found people in this country quite suspicious of them. She believes this is because they tend to think of the poor quality housing stock built in the post-war period.

    Incorporating good landscaping encourages people to talk to each other

    Clare talks about contemporary vernacular design as a way to have mass produced housing that retains a sense of identity through the varied design of the homes and getting the landscaping right.

    She cites an example in Holland where a group of architects took inspiration from a Mondrian painting to create different types of good-quality houses dotted around bisecting canals and green spaces. Clare compares how this development felt like home, whereas the new build houses local to her in the UK feel like a toy town, soulless, hence the subtitle of her book.

    Faro Architekten project in Biesland, Holland

    Another case study in Wales had open-ended gardens that led to a lake at the back where residents got to know each other because they often walked there. The design further encouraged interaction by incorporating a shared garage rather than individual drives.

    Great House Farm project in Wales

    Only residents really know whether housing design works

    As well as interviewing architects, designers, housing associations and property developers, Clare made sure to speak to a good selection of the residents at each housing scheme to find out what actually worked.

    While she often heard about teething problems, these resolved themselves and some of the small developers even had the foresight to anticipate and make provision for them. Resident feedback was summarised into four categories:

    1) Comfort – is it warm enough and is it light enough?

    Clare found the levels of insulation and daylighting were better than building regulations dictate. She comments that it’s really important to have bigger windows because seasonal affected disorder could be caused by being inside so much of the time.

    2) Appropriateness – how appropriate is the scheme for the area?

    Good design takes into account culture and context (i.e. the surrounding buildings and landscape, local materials and craftspeople). Therefore you need different types of housing for different types of area. Clare gives the example of a Norfolk development where they rejected the aesthetic of individual suburban plots; the site meant the front gardens were south facing and the architects chose to only separate them minimally with green wire fencing. The result was like a barn in a landscape.

    3) Sustainability – does the design consider the embodied energy as well as the cost of running the home?

    The focus in the UK is to save on energy bills but materials should matter too. Clare found examples such as Sieben Linden in Germany where they built everything out of straw bales and timber frame.

    Sieben Linden eco village in Germany

    4) Improvement – is the housing an improvement on what is currently built locally?

    Clare deliberately sought out developments that she felt did better than the status quo, and found that on the whole residents were really happy with the quality of life afforded by the housing and sense of community. “They were just very happy to live where they lived and they didn’t want to move. Which I think says it all really.”

    The current dominant building culture in the UK restricts progress

    Clare was really excited to meet some progressive and interesting developers who are trying to do things differently with their residents and the planet in mind, but notes that the existing culture prevents widespread expansion of such practices.

    She observes that in the UK six big housebuilders are dominating the landscape and what the edges of our towns and cities look like, adding that everyone she talks to seems equally frustrated with what she calls ‘the standard redbrick box plonked everywhere’. Clare compares this with Europe where individual developments respond to local demand.

    European governments regulate development differently

    In Sweden, no more than 100 houses can be built by any one developer in any one area, which creates a diversity in housing. And in Vorarlberg in Austria, anyone who owns a piece of land can build on it as long as the design (which can be modern) is considered appropriate for the region.

    There are cultural differences on the continent as well. In Germany, people often build together in ‘baugruppen’, and they think long-term so they build very good quality homes typically passed on to the next generation.

    UK decision makers are beginning to value ‘community’

    Historically, councils have gone with the highest bidder when selling land for housing development, and the big companies can outbid the smaller ones. However, councils are now starting to see that a slightly lower bidder can deliver much higher long-term benefits. For example, mixed-use schemes improve the sense of community, making people want to stay and resulting in less maintenance and increasing the scheme’s longevity.

    Gavin Barwell, Minister of State for Housing & Planning, has said that the government is going to make it easier for smaller developers to get land and to start developing. Clare finds this encouraging and hopes it will become easier for self-builders too.

    Self-builders need to register their interest

    At the moment, planning authorities have to find out if there is a need for self-build land and then if there is, they have to provide it. In some cases it’s proving difficult to actually get councils to follow through, but Clare thinks the housing white paper will help to move things forward, saying: “I think it’s quite exciting times now. I’m really hopeful for the future of housing and house building in Britain.”

    Find out more

    Visit the website of Clare Nash Architecture

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    Transcript

    Download a transcript of the interview with Clare Nash

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  • HPH094 : 10 Insulation Types and When to Specify Them – with Brian Murphy from Green Building Encyclopaedia

    HPH094 : 10 Insulation Types and When to Specify Them – with Brian Murphy from Green Building Encyclopaedia

    Brian Murphy from Green Building Encyclopaedia runs through the most common types of insulation and explains why they each have strengths and weaknesses.

    BRMShoulders

    Interview with Brian Murphy

    Brian has spent 40 years in the industry, as an architect and as a specification writer. In that time he has specified over £2400 million worth of work, so knows a thing or two about insulation!

     

    Insulations Can Be Categorised Into One of Three Groups, According to How Heat is Transmitted

    These groups are conductivity insulation, convection insulation and radiation barriers. They each have different characteristics, and for this reason there might be a need to use more than one type for a situation.

     

    Brian talks us through the characteristics, and pros and cons of 10 of the most common types of insulation.

     

    1. Glass / Rock Mineral (Stone Wool) Insulation

    Usually the lowest priced, this tends to be the most widely used insulation. Its main use is for conductivity thermal insulation. It also rejects water and is fairly versatile in where it can be used, though it isn’t ideal for timber roofs or timber frame. Stone wool is often used when fire resistance is needed, and glass wool in an acoustic performance situation. Enormous amounts of energy are used to make the glass or stone wool products, for example to melt stone and then blast it with air to turn it into a fibre.

     

    Glass wool
    Glass wool
    Rock wool
    Stone wool

    2. Polystyrene and Other Plastics

    The plastics all have different characteristics, formats and some have different gases within them, and legislation over time has made those gases less harmful to the environment. The gases inside produce the bubbles, which is what makes the material insulating.

    They are versatile in that they can be blown in, sprayed on, expanding, applied as a solid material and cut to a concertina, etc. Some are water resistant and durable and can be used under floor slabs, in roofs and others used in Structural Insulated Panels (SIPs). The SIPs panels have very little of the radiant protection from solar gain but a lot of the required characteristics for conductivity thermal insulation, so heat that gets in is slowly let out and could risk overheating.

    Polystyrene foam
    Polystyrene foam

     

    3. Cellulose Fibre

    This is recycled paper or magazine waste which has been flaked and is blown into open or closed timber framed cassette cavities, either in a wet or dry method. It is blown in powerfully in order to reach every corner of the cavity. Blown in methods reduce the risk of heat loss or condensatioin the imperfection gaps created by cutting insulation boards and batts to fit frames.

    CelluloseFibre

     

    4. Sheep’s Wool

    As well as being hygroscopic and effective in terms of moisture buffering, Brian says that some research has found sheep’s wool strangely warms up when wet and cools down when dry.

    It’s eco credentials are challenged however by some quarters focusing on the high methane levels from the sheep! Historically, also, UK sheep have been dipped, leaving chemicals in the wool which have needed to be processed out. Modern farming practices have moved on.

    Brian explains that another issue is that sheep’s wool can be squashed whilst packed, though some products on the market have plastic fibre added in to bounce back to full thickness. Sheep’s wool is used in timber framed construction and roofs.

    SheepsWool

     

    5. Cellular Glass

    Brian explains that this is versatile but can be more expensive than many other insulation materials. It is fire resistant, rot resistant, animal and rodent resistant. It has vapour resistance and is watertight but should always be encapsulated with water resistance to avoid frost damage. It has conductivity resistance, and has radiant heat barrier properties.

    It is ideal in roof, gutter, basement and foundation construction. Because of the cost, Brian recommends using it where you can afford to, with damp places being ideal.

    FoamGlass

     

    6. Dense Wood Fibre

    This is extremely versatile and comes as a rigid, soft or combination material. It has acoustic, conductivity and radiant barrier performance, and can be used in or on timber frame or roof and for external insulation with render or rainscreen weatherboarding.

    It is also ideal for retrofitting old properties with solid wall construction which need to be able to breathe inwards or outwards. Exceptionally one manufacturer has developed a version for partial ventilated cavity masonry walls; not normally recommended.

    Dense and soft wood fibre
    Dense and soft wood fibre

     

    7. Aerogel

    This is a silica based product that was invented by NASA. It can be very thin and exceptionally high conductivity performance and is popular when used with other materials for dry lining walls. Comparing it in price to some of these other materials it can be expensive and therefore Brian suggests again using it only in the places where it is needed; such as at thermal bridges that risk condensation and mould. Examples include: at door and window surrounds and where rainwater and soil pipes interrupt external wall insulation and below DPC; but they need specially developed weather and ground water protection to survive.

    Aerogel+Boards

     

    8. Calcium Silicate

    This is a very lightweight material that was designed for historic buildings. It is low impact, high performance with good moisture transport characteristics allow in solid walls to breathe.

    CalciumSilicate

     

    9. Vacuum Insulating Panels

    Air is sucked out of a silica ball filled, aluminium foil wrapped panel to create a vacuum. They’re ideal for a modular design where things don’t have to be cut to size. In a retrofit situation they would probably need to be combined with another material, such as aerogel or dense wood fibre; but bespoke sized panel services are also available.

    These panels would need to be used in areas where there would be no risk of someone accidentally nailing or drilling a hole into them!

    vacuum_insulating_panel

    10. Insulating Render

    This is a fairly new material to the UK market, and is a render which is insulating throughout its thickness. It’s applied like a render and doesn’t need vapour barriers or special membranes. It is a mixture of special earth and other ingredients, such as a cork aggregate, which would need to be applied to a thickness of around 100mm or more and can accommodate an uneven existing surface.

    DiathoniteInsulatingRender

     

    Find Out More

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    Download a transcript of the interview with Brian Murphy.

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  • Google+ Hangout – Should We Optimise Housing Density for a Sustainable Future?

    We’re pleased to announce our second debate session on Google+ Hangouts. Previously we talked about finding the balance between heritage and sustainable design.

    This time: Should We Optimise Housing Density for a Sustainable Future?

    We’ll explore the benefits and drawbacks of creating high and low density housing, whether there is actually an optimum housing density and if so, would it make sense for all housing developments to aim for it?

    San Francisco Neighborhood

    The Panel (so far)

    Matthew Cutler-Welsh from Home Style Green

    Ben Shideler from Elan Construction

    Philippa Richard

     

    As before, I’ll be hosting the debate, which we’re hoping to bring to you in video this time. Last time there were a few bandwidth issues (which forced us into audio only) but we think we’ve overcome these now (famous last words!).

     

    The discussion takes place on Friday 16th August 2013 at 8pm GMT+1 and you can watch it here live.

    After the event it will also be available on our YouTube Channel.

    If you have a good idea for a future debate or you want to join in another time, then please get in touch.

  • HPH020 : An Introduction to Ventilation in The Home – with Andy Simmonds from Simmonds Mills Architects

    HPH020 : An Introduction to Ventilation in The Home – with Andy Simmonds from Simmonds Mills Architects

    Andy Simmonds from Simmonds Mills Architects explains ventilation in the home, why it’s important and what the options are if you’re looking to retrofit a property for energy efficiency.

    Andy-Simmonds

     

    Interview with Andy Simmonds

    Aged 12, Andy got his first taste of sustainable construction taking a few courses at the Centre for Alternative Technology. After attending architecture college, Andy worked with engineer Chris Wallis, son of Barnes Wallis, on numerous interesting projects including stonework, timber frame construction, repairing windmills, etc. With a love of nature and the countryside, he developed an awareness of the importance of ecology when designing and building. As well as running Simmonds Mills Architects he is part time Chief Executive of the AECB (the sustainable building association).

     

    The AECB is a Network of People with a Common Aim of Promoting Sustainable Building

    Andy gives some background about the AECB. It was set up by a builder and his wife in 1989, focussing on construction but with an awareness of ecology and the environment. It’s got a very broad mix of members and there are many resources, such as the low energy buildings database, the technical discussion forums, the annual conference, local groups and so on. With about 1500 members, this vibrant group of people share their practical experience and expertise with each other. Andy says it’s a very fast way of learning, getting to grips with things and improving your business as well.

     

    Ventilation is Necessary to Get The Air to Breathe, But Also to Remove The Pollutants

    Andy uses an example of the International Space Station to illustrate the fundamentals of ventilation. They are in a sealed unit (although not completely airtight) and need air to breathe, but also a way to flush away pollutants. These could be carbon dioxide or other gases created by equipment, etc.

     

    Early Buildings Just Let The Wind Blow Through

    Although early buildings had a lot of natural ventilation, some stone and brick buildings with solid floors were actually pretty airtight. As people found new ways of building, some constructions (from 60s, 70s and 80s, for example) were potentially leakier and more open to the elements than some of the older buildings. Draught proofing without thinking of ventilation can create quite unhealthy environments.

     

    Over Ventilating and Under Ventilating Are The Two Extremes

    A house with all its windows open could be an example of over ventilating. This might be useful to clear a fug but if it’s cold outside, a lot of heat energy from the house will be wasted during ventilation. The reverse situation could be keeping all the windows shut and draught proofing well, so any pollutants from off-gassing carpets (for example) or from cooking with gas hob, etc., cannot escape. In the heating season neither of these extremes is an effective way of ventilating a house and getting good air quality.

    andy-simmonds-(by-window)

     

    In a Retrofit, Mechanical Ventilation Lets You Control The Situation

    Mechanical ventilation is an approach that’s becoming used much more often. Two systems worth considering at are extract-only or mechanical ventilation with heat recovery (MVHR).

     

    Extract-only Mechanical Ventilation

    This approach extracts air from wet rooms, kitchens, bathrooms and so on, and then the fresh air is drawn in through trickle vents in the windows. These are slots in the windows, which will provide a background level of fresh air coming into the house. However, with the extract ventilation system, which is basically a box with a fan in it, the air is continually pulled through at a very low level. Even with a peak load during cooking, for example, this background ventilation can cope without turning up the fan.

     

    Incoming Air From Trickle Vents Will be at The Outdoor Temperature

    Andy explains that on a cold winter’s day, you might feel that incoming air as a cold draught if you’re sitting near the window. This is why radiators have often been positioned underneath the windows, so as the cold air comes in it falls down and to some extent warms up. Andy outlines a good approach used in Scandinavia, where they put an air inlet through the wall, maybe behind the radiator, so as you pull in air from outside it comes and warms itself on the radiator and doesn’t feel like chilled air.

     

    Mechanical Ventilation with Heat Recovery Provides Fresh Air and Keeps The Heat

    Mechanical ventilation with heat recovery both extracts the air from the wet rooms (kitchens, bathrooms and so on) but also puts it back in via ducts and air terminals throughout the house. This is therefore a balanced system. Although the heat is taken out of the outgoing air and put back into the incoming air, the air itself doesn’t mix. The heat is transferred as the air crosses through a matrix, a plastic honeycomb for example. So just the heat is transferred. The warmed incoming air is fresh.

     

    In a Low Energy Retrofit, Ventilation Air and Air Leakage are Considered Separate Issues

    Andy points out that until recently ‘ventilation air’ and ‘air leakage’ (the air that finds its way in through cracks, gaps and holes in the building) were much the same thing. However, in a low energy retrofit where the objective is to make the building as airtight as possible, the issues are considered separately. Creating and designing a system specifically for ventilation is vital.

     

    Think About Ventilation From The Outset

    Your ventilation strategy will depend a lot on the building you’re hoping to retrofit. Once you have a professional assessment of how airtight you can make the building, then you can make an appropriate strategy. British houses from the 1970s and 1980s can be difficult to make airtight, whereas solid-walled properties with solid floors are often much easier. This year the AECB aims to release a retrofit guidance programme to help in this process.

    grove-cottage-front

    Grove Cottage meets the EnerPHit standard

    Larger MVHR Units Are More Efficient

    Andy talks through the MVHR unit he has at Grove Cottage, which has two low voltage, low wattage fans, one for extracting air from the house and one for pulling air into the house. The largest part of the box is the heat exchanger. Andy’s unit is situated behind cupboard doors in a utility room. While it does take up a fair amount of space, Andy points out that the larger the unit, the more efficient. This is because the more space the air has to move through, the less work the fans have to do, so very small units tend to be much less efficient than Passivhaus certified units.

     

    Mechanical Ventilation Only Makes Sense With Certain Levels of Airtightness

    Andy generally only recommends mechanical ventilation with heat recovery when the air change rate for the house is less than 1.5 air changes per hour. This is because the savings must warrant the investment in electrical energy. However, for the extract-only system an air change rate of 3 would be acceptable. Part of the difficulty is in planning for the air change rate when you’re deciding what sort of ventilation system to have, because after construction you may not have achieved the level of airtightness you had hoped for!

    grove-cottage-(snow)

     

    Externally Insulating Grove Cottage Was an Easy Route

    Andy explains his approach to retrofitting Grove Cottage, which is a solid brick house. As the brickwork was of no particular architectural quality – it was painted white – externally insulating was the easier option (compared to internally insulating). The starting point was to mark on the plans in a red pen where the continuous air tightness plane goes, forming a strategy of how to deal with weak points. Andy describes how he sealed the brickwork to the roof membrane (which is basically a plastic sheet) with bitumen tape, which proved to be very successful. He emphasises the importance of a clear strategy and not leaving it to the last minute.

    grove-cottage-(back)

     

    The Right Advice Can Save You Money

    It is essential to spend time early on thinking through the detail of the retrofit. This could stop all sorts of problems arising on site and prevent a poor result at the end of the job. Andy reflects on how people can be reluctant to spend money on these services, preferring to invest in the measures instead. However, this upfront thinking could actually save a lot of money.

     

    Maintaining a Ventilation System is Not Onerous

    Andy’s MVHR unit runs throughout the year and supplies fresh air which is slightly warmed by the outgoing air (although it’s not a heating system) to about 21 degrees. The system has been set so that the fans go up to a higher speed around mealtimes, etc. While you can adjust it manually on the control panel as required, most of the time no intervention is necessary. The one exception to this is when the cardboard and fleece filters need changing. A light on the unit may even indicate when to do this.

     

    Make Sure You Have Easy Access to Your Ventilation Unit

    Think carefully about where the ventilation system is located. If it’s positioned in the loft or screwed down behind a panel, this will make the simple maintenance jobs more of a pain. Equally, in a retrofitted house like Grove Cottage (that has been well-insulated and has triple glazing, etc.) and is therefore peaceful, you want to locate the ventilation units away from quiet spaces. There will be a slight hum, so keep it away from sleeping areas, for example.

     

    Ventilation Systems Must be Properly Commissioned and Balanced

    When these systems are put in, it’s very important that they are commissioned and balanced properly. There’s a number of reasons for that, but in terms of comfort, over ventilation could mean that you start to notice draughts!

     

    Not Considering Ventilation Could be a Health Risk

    Andy outlines his concerns about the choices some people are making with their homes. He gives an example of putting in a wood stove. Leaving aside the combustion products and air pollution, Andy suggests that without an external air supply vent for the wood stove, you will be pulling in cold air up through your basement, through the floorboards and cracks and gaps. This will create cold draughts, which will add to discomfort, but the whole reason the stove was installed was to be more comfortable!

     

    MVHR Systems For Retrofit Likely to be a Small Niche

    Andy believes that we need to be much more conscious of ventilation because air quality is very important. He sees mechanical ventilation with heat recovery as being a relatively small niche for retrofit, but that extract-only ventilation could have a bigger role to play.

    grove-cottage-(grass-roof)

     

    Useful Links

    Download a PDF About Retrofitting Grove Cottage 

    Simmonds Mills Architects

    Follow Andy Simmonds on Twitter

     

    Transcript

    Download a transcript of the interview with Andy Simmonds.

     

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  • Google+ Hangout – The Balance Between Heritage and Sustainable Design

    At the start of the year we mentioned that we wanted to host some Google+ Hangouts to debate issues that are not so clear cut.

    We are pleased to announce that our first forum will be on Monday 18th February 2013 at 8.30pm.

    google-plus

    A panel of experts and home owners will get in front of their webcams for the debate and the programme will be transmitted live on YouTube. A pre-recorded version will also be available to review after the event.

    Our subject for this first session is:

    The Balance Between Heritage and Sustainable Design

    What’s more important – preserving heritage architecture or retrofitting it to high energy efficiency? There has to be a balance between the past and the future, particularly if we accept that we have to reduce our fossil fuel dependency. Where is that line?

    Our panel consists:

    Writer and blogger Roger Hunt (who appeared in our 10th podcast)

    Writer and Passivhaus consultant Adam Dadeby from Passivhaus Homes (who appeared in our 5th podcast)

    Homeowner Ross Atkin (who has recently retrofitted his Victorian house)

     

    Ben Adam-Smith will be leading the discussion and it is scheduled to be 30 minutes long.

    The programme will be available on our YouTube Channel.

     

    Would you like to get your voice heard on this topic? Either get interactive as the broadcast goes out or send an email with your thoughts in advance.