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CNA visit to Straw Bale House by Sarah Wigglesworth Architects

Recently Clare Nash Architecture Ltd. (CNA) visited the famous Straw Bale House in North London designed by Sarah Wigglesworth and Jeremy Till. With sustainability and eco design at the centre of CNA’s design approach, we were excited to be given a tour by Jeremy himself who explained how their pioneering project came about.

The team met outside the house-come- office’s tall wicker gates at the very end of Stock Orchard Street in London. With the railway on one side and Victorian terraces on the other, a building on gabion stilts with sand bags on one elevation is not quite what you would expect to find at the end of the road!

Luckily it was a dry (if a little chilly!) day as the tour started outside, with Jeremy explaining how the design concept for the Straw Bale House was developed through Sarah and him sharing stories, before any drawings were even started. Once the design was established through drawings the next challenge was getting it through planning, which was perhaps aided by one of Jeremy’s anecdotes involving a party for local residents. The building is well known for being the first straw bale house to be granted planning permission in the UK, however there are many other materials at play here including sandbags and stone gabions which certainly challenged ideas on conventional building materials at the time. The talk outside lasted for about an hour discussing structure and sustainability.

Turning the corner around the house it was a pleasant surprise to find their garden, a surprisingly green and spacious area for central London. As lovers of fresh vegetables, it was great to see what crops they were growing in their garden and to hear the clucking of chickens too! Mid-construction decisions led to only having a back door which is now the front door and works well as it encourages you to walk through the garden before entering the house.

Walking inside and up the stairs I was not sure what to expect of a space which is both living and office, shared and private. However, the top of the stairs greeted us with a warm open plan living space that was cleverly divided into functional spaces; making sense of the unusual floor layout which was organised around an organically shaped larder inspired by Malawi cooking ovens. The use of natural wood and exposed white painted steelwork could have had a cool industrial feel to it but was complimented by splashes of warm orange furnishings and large amounts of glass allowing natural light to flood the space enhancing the feeling of homeliness. One of my favourite areas was the kitchen which was again homely and quirky too as each item seemed carefully considered, perhaps handcrafted, all the way down to the papier mache lampshade suspended over the table.

A fairly large group were on the tour with us but after admiring the first floor, we ascended the (perhaps not quite building regs approved!) staircase into the tower. Lining the stairs were shelves and shelves of books which seemed to change in levels of architectural relevance the further up you went. So at the bottom were architectural text books while at the top, nearing Jeremy’s office, were fiction books and novels. Having a library like this might get tiring in reality but as a visitor it was a very charming idea!

On our way out we popped into Sarah Wigglesworth’s attached (Quilted) office where she was working. It was an impressive space, both organised and bright and surprisingly quiet despite being on the railway track side- the sandbags must be doing their job!

Although the project is known for having challenged ideas of structure and materials in terms of sustainability, it was very interesting to hear Jeremey Till say that the construction methods and material composition are actually not that sustainable in the context of what is possible today. Technology has moved on since the house was originally built; even the double glazing is no longer as efficient as it could be!  Nonetheless, the choice and composition of the interior materials and spaces has a certain quality to it that, while you could probably Google ‘Sarah Wigglesworth House’ or something similar; would just not be the same as experiencing in reality.

 

 

 

5 Designs that Challenge our British Perceptions of “Home”

While researching abroad, Clare discovered that no matter what culture you live in, our needs from a home are quite similar. However British perceptions of home are known to be fairly conservative, especially in comparison with more contemporary living styles seen in Europe.

Below are 5 case studies taken from Clare’s book highlighting some interesting challenges to these views, with better quality housing as the result.

Last year, the RIBA ran an exhibition called “At Home in Britain: Designing the House of Tomorrow”, that explored how three common types of home (cottages, terraces and flats) can be reimagined for modern living.  The challenge of updating these familiar housing types involves a response not only to a housing crisis, but also a crisis of identity.  Home is not just where we are, but who we are.

As our lifestyles change, so do our perceptions of “home”.  In her new book, Contemporary Vernacular Design, How British Housing can Rediscover its Soul, Clare Nash investigates a number of housing designs that take a familiar concept or design feature and adapt or update it to meet current needs and desires.

So what are British perceptions of home and how do the below housing schemes challenge them?

Open-ended gardens

Why does a garden have to be enclosed on all sides?

Gillard Associates’ Great House Farm is a terrace of homes with open-ended gardens, joined by a communal green space beyond.  The chance encounters and easy interactions created by removing a barrier have generated a lovely sense of community.

Why do garages all have to be individual and accessed by separate drives?

This requirement for privacy and ownership by the British public creates the unattractive sea of tarmac we see in most new-build housing schemes today. But it needn’t be like this. The open and shared garages at this housing scheme, offer opportunities for people to get to know each other, to strengthen the community, something we know reduces crime and improves happiness and wellbeing. It also provides more efficient use of space, something badly needed with our growing population.

challenging British perceptions of Home

Gillard Associates’ Great House Farm

The front garden is the garden

Outdoor space is often considered secondary to the indoor space of the “home”, and many modern forms of housing do not have the option of a garden, especially in urban environments.  Mole Architects’ Broadland houses in Fulmodeston only have front gardens, with little “sentinel” bike sheds acting as gatehouses facing the street.  Bringing the main outdoor space to the front of the house is a simple and subtle way of not only respecting traditional local house layouts, but also challenging any distrust or reclusiveness that could damage the social aspects of the scheme.

contemporary vernacular housing

Mole Architects’ Broadland Housing in Fulmodeston

broadland housing gatehouse

Communal green space improves security & combats loneliness

Patel Taylor have used outdoor space in their Courtyard Housing in Barking as a way of overcoming the stigma associated with bungalows, especially for the elderly.  Each house has its own south-facing private courtyard – a small space for the residents to stamp their own identity on and enjoy.  In the centre of the scheme is also a communal green space, visible from the private courtyards and resident’s living rooms.  This combats loneliness and brings a sense of space to an area of quite high density. It also increases security due to easy surveillance opportunities.

patel taylor courtyard housing

Patel Taylor’s Courtyard Housing

Challenging traditional housing form

Faced with the challenge of designing something urban yet homely, Mæ Architects took the concept of the typical semi-detached house and tinkered with it in their housing scheme “The Guts” in Manchester.  To achieve density and room for parking, the houses are turned 90 degrees, spanning the length rather than the width of the plots.  These create the ‘back to back’ terraces seen below, themselves providing not only parking but also roof terraces. Not usually a feature of social housing, the roof terraces add something special, normally only possible for the self-builder. A direct result of thinking outside of the box and challenging British traditions.

Mae The Guts

Mæ Architects’ “The Guts”

No more plastic chimneys please

Our over the top conservatism has sadly created a world where planners require chimneys and developers provide plastic ones, a huge waste of resources and only adding to the superficial nature of new-build box homes that litter the edges of suburbia. We are missing an opportunity to improve well-being. At “the Triangle” in Swindon, Glenn Howells Architects took the instantly familiar typical terraced house and gave it a huge eco-upgrade.  The chimneys are used to reduce overheating and provide fresh air using the chimney for passive stack ventilation (where heat rises and causes the air to circulate). There is no doubt that real chimneys (not plastic) do improve the appearance of homes, particularly terraces, but it is daft to include them purely for aesthetic reasons. The Triangle scheme offers the benefits aesthetics and improved health. One of the residents interviewed for Clare’s book said that his asthma had almost disappeared living in a fresh air environment.

In addition, a low-impact, high-performance building fabric (Tradical Hemcrete® and lime render), combined with enlarged windows and ceiling heights, has produced a recipe for terraces with a “classic” appearance and a high level of comfort and satisfaction.  Outdoor space is again a major factor in the success of the scheme.  The landscaping strategy by Studio Engleback includes sustainable drainage, water harvesting and food production, raising the value of the housing both financial and social terms.

The Triangle Glenn Howells

Glenn Howells Architects’ “The Triangle”

All these schemes have used familiar representations of “home” as their starting points, but reinterpreted them through a contemporary lens.  This is the essence of Contemporary Vernacular architecture, and something the team at Clare Nash Architecture Ltd hope to see much more of in the future!

The Community Infrastructure Levy and what it means for self-builders and barn conversions

Community Infrastructure Levy Barns

A piece of legislation has recently been adopted by South Northamptonshire and South Oxfordshire district councils affecting certain developments that have been granted planning permission on or after the 1st April 2016.  This is a charge called the Community Infrastructure Levy (CIL) which applies to new residential and retail developments. Most other councils will also now have starting applying this charge.

The Community Infrastructure Levy (CIL)

The Community Infrastructure Levy (CIL) is a charge that local authorities in England and Wales can choose to place on new developments, usually those with over 100m2 of floorspace, or that create one or more new dwellings.

Please note; this charge only applies if you are creating new-build floor space such as a new-build dwelling or a large home extension (over 100m2). This can also be a mezzanine level in a barn conversion. The CIL charge will apply to the new build floor space only (so the area of the mezzanine or extension) and not to any existing floor area.

It came into force in 2010 and coincides with restrictions on the use of planning obligations (also known as Section 106 agreements).  A CIL enables the local authority to raise more money for local infrastructure improvements than Section 106 obligations. It also provides developers more certainty about costs, as it is a fixed charge.

Section 106 agreements and CIL

The CIL regulations can be complex. However, it is important to consider how it may affect you if intending to convert an existing barn or build/extend a new residential property in the future.

How might the CIL affect a barn conversion?

The good news is that changes of use, such as the conversion of a barn into a dwelling, do not usually attract the CIL for two reasons.  Firstly, a barn conversion does not usually involve creating 100m2 or more of new floorspace.  Secondly, floorspace that has been in legal use for a continuous period of at least six months within the 12 months preceding the granting of planning permission is disregarded when calculating CIL (See Section 40 of the Community Infrastructure Levy Regulations).

Section 40 of the CIL Regulations

But, you might be liable for CIL if your barn conversion involves creating additional new-build floorspace (e.g a mezzanine or extension to the barn). Here the levy would only apply to the additional floor area, not the total building area.

How might the CIL affect self-builds/extensions?

A government initiative to stimulate the self-build market means that a development can also be exempt from the CIL if it is a self-build/extension project.

There are three types of self-build exemptions; for a whole property, for a residential annexe and for a residential extension.

  1. Whole Property

Those claiming exemption must own the property and use it as their primary residence for a minimum of three years post-completion. If the self-builder sells or rents their property within this period, they will be charged the full levy of their area.

  1. Residential extension

If certain criteria are met (see regulations 42A and 42B), then a self-builder will be exempt from paying the levy for extensions. For example; the main house must be the self-builder’s primary residence and only if the proposed extension enlarges the primary residence i.e. it is not an additional unit. Extensions less than 100m2 are already exempt according to the minor development exemption.

Regulations 42A and 42B

In both cases it is important that the correct procedure is followed in order to receive a notice of exemption; including not starting works before this is received. It is important to note that even if these types of projects do not require planning permission, the CIL will still be charged unless exemption applies.

Ultimately, the landowner is responsible for seeking CIL exemption, or, is liable for paying the levy within 60 days of commencement of the works. CIL payments are usually made in cash, but can also be paid “in kind”, for example through land.

CIL charges

Both councils use Charging Zones to determine the CIL cost, and have produced corresponding maps. In South Northants there are three main categories for charges; rural, urban and Sustainable Urban Extensions (SUEs) which range between £50/m2- £200/m2. In South Oxfordshire residential development can be liable for a charge of up to £150/m2. Both councils have produced Charging Schedules that set out the charges and answer FAQs.

South Northants CIL Information

South Northants CIL Charging Schedule

South Oxon CIL Information

South Oxon CIL Charging Schedule

 

October 5, 2016
The Community Infrastructure Levy and what it means for self-builders and barn conversions

A Contemporary Vernacular Housing Development Design

As Clare has spent so much time researching what makes a great housing scheme for her book, the team was excited to have the opportunity to have a go at designing a contemporary vernacular housing scheme ourselves!  Earlier this year Clare Nash Architecture Ltd (CNA) was approached by a developer looking to build eight houses on the site of an old farmyard in Cambridgeshire.  The intention was that young families looking to move out of the city could settle down here.  Although the extent of CNA’s involvement was just to produce a quick sketch scheme, it was a terrific chance to design collaboratively and apply some of the principles of contemporary vernacular design.

contemporary vernacular housing development

Overview of proposal

Daylighting, visibility and privacy

Daylight is top priority for any architect, and in a scheme based around a courtyard such as this one, it is important to make sure that everyone gets their fair share.  Some occupants benefit from south-facing gardens, so in the interest of fairness it is important to be creative with the shape of the other homes so at least part of their gardens benefit from bright sunlight.

The CNA team liked the idea of openable walls, like the Tekapo Shed by C Nott Architects in New Zealand, so that the building can adapt to the weather, and play with the boundary between inside and outside.  We experimented with a few ways of using glazing to maximise natural lighting, yet maintaining a sense of privacy.  We were keen to achieve a “Goldilocks” level of visibility, not so little that residents don’t interact with each other and don’t feel secure, and not so much that they feel encroached upon and under surveillance.

contemporary vernacular housing corner window

Corner window idea

contemporary vernacular housing angled shutters

Angled shutters idea

“Bang for your buck”

Creating value for money is not synonymous with scrimping on the quality of materials and craftsmanship; it can often be a matter of thoughtful and careful design. Embracing the industrial nature of the site and keeping to a tight material palette is a good way of creating a striking aesthetic, yet at the same time keeping costs down.  Another feature that increases the appeal and value of the proposal is that each house is unique in some way, yet they all have a coherent identity and it is clear they belong to the same scheme.  This affords each house a sense of individuality, allows future occupants a choice of features in their homes, and enhances the character of the development, making it stand out from the rows of “cookie cutter” houses we have become used to seeing.

contemporary vernacular housing sketch plan

Each house would have a feature that makes it unique

Material palette

Identity and character are ways in which a neighbourhood defines itself within its context, and also how it can set itself apart and be distinctive. Brick, dark timber, and clay tiles are traditional, inexpensive materials used a lot in this part of the world.  They are also easy to reclaim and reuse, and to update for use with a more contemporary aesthetic.  This simple material palette set out our intentions for the scheme: a friendly, familiar character that offers the benefits of a modern lifestyle in a rural setting.

contemporary vernacular housing green courtyard sketch

View into the internal courtyard space

Access and movement around the site

How people move around a housing scheme is a crucial design element.  This is one of the greatest contributing factors to the sense of community within the scheme, as circulation dictates how people interact with one another.  The scheme is based around a central green courtyard, which is distinctly public.  Trees ensure that houses facing each other do not directly overlook each other, and shade the shared space below.  This courtyard is a pedestrian area, although there is room for cars to drive up to the house entrances if this is necessary, cars would usually be parked in garages close to the site entrance.  The houses each have their own private back gardens, and these can be accessed through alleyways leading off the main square, signalling the transition between public and private outdoor space.

housing scheme sketch alleyway

Central alleyways idea

housing scheme sketch alleyway

Possibility of live/work

The dream of settling down in the countryside becomes dampened somewhat if you still have to commute to the city to work.  The possibility of working remotely has meant that “non-office” ways of working are becoming more usual (just as we do at Clare Nash Architecture Ltd!).  The housing scheme we proposed offers offices along with the houses to create a live/work scenario, in anticipation of the lifestyle that suits young families today.

open garages with offices above

Garages with space for offices above

“Sense of place”

The notion of “sense of place” is a key theme running through Clare’s book and was a key factor for her in choosing case studies.  Although it can be difficult to define, a strong sense of place is the result of a strong identity, relationship to surroundings, and ultimately the behaviour of a place’s inhabitants.  An absence of this sense leads to an eerie, quite uncomfortable feeling – the opposite of “home”.  At the end of the day, it is people and communities who create a “sense of place”, but this does not absolve architecture and design of responsibility for this!  Working on even short projects such as this, and helping to research the case studies in Clare’s book, has brought home how even the smallest of design decisions can have a huge impact on how people behave, and their mental wellbeing.

 

CNA Away Day (Part I: NewhallBe Housing)

It’s not all work and no play at Clare Nash Architecture Ltd (CNA)!  This summer the team had an “away day” in which we visited the NewhallBe housing Project near Harlow and the new extension to the Tate Modern by Herzog & de Meuron Architects.

We were all extremely interested in seeing the Newhall Be housing designed by Alison Brooks Architects.  Having assisted Clare in researching and editing her book, Katie and I were keen to experience an exemplary housing scheme off the page.  The team caught the train to Harlow and then the bus to Newhall, passing by typical utilitarian New Town architecture set on the unforgiving flatness of the East Anglian landscape.

Essex barn Newhall

Traditional Essex barn

When we got off the bus we walked down a pleasant pedestrian/cycle route into fields, away from the bustle of the main road.  One of the first buildings we came across was a traditional Essex barn, reminiscent of rural Dutch architecture with its striking black boarding and half-hipped roof.  Alison Brooks has said that barns like this were her inspiration for the materiality and form of the Newhall Be housing, so this was a nice piece of foreshadowing on our approach.

Newhall Be housing

Alison Brooks’ Newhall Be housing

Newhall Be Alison Brooks

Upon entering the Newhall development we found Brooks’ houses very quickly – each “neighbourhood” designed by a different architect is very distinct, and the Newhall Be houses are instantly recognisable by their distinctive dark cladding and angular roof shapes.  It was a Wednesday lunchtime, so most people were at work, and there was a real sense of stillness about the whole site.  It felt almost like looking around a film set, or perhaps a model village.  Although there are lots of street-facing full-height windows and doors, most houses had their blinds drawn.  There is plenty of green planting around the site, and this did mitigate the “empty” feeling somewhat.  Although none of the houses have back gardens, people had made use of their balconies and patios as spaces to bring in some colour and greenery.  There is also a large playing field very close by, which serves as a common green space for everybody.

Alison Brooks Newhall Be housing   Alsion Brooks Newhall Be housing

Newhall Be (and the wider Newhall project) could be described as an updated version of the New Town philosophy.  It meets people’s needs and thus creates a quite urban feeling in a rural setting, rather than imposing a twee imitation of a traditional village onto bright young professionals.  It doesn’t fight the difficulties that arise in creating a community from scratch, and in accepting these challenges it has produced a new type of community.  People are able to maintain their “metropolitan” outlooks and behaviours, while still living in a small suburban neighbourhood.  Using vernacular architectural styles and methods of place-making as inspiration, rather than a rigid template, Newhall Be offers something that feels modern, yet also familiar.  I would just like to go back on a warm summer’s evening and see it come to life a little more!

October 1, 2016
CNA Away Day (Part I: NewhallBe Housing)

‘Non-Office’ Working – Designing Collaboratively

'non-office' working‘Non-office’ working

People are often very interested by the ‘non-office’ working approach at Clare Nash Architecture Ltd (CNA).  Rather than working from a fixed location (and dealing with all the associated overheads), the CNA team work remotely, with weekly meetings to share updates and assign tasks.  These meetings often run back-to-back with site visits or client consultations for time efficiency, and take place in cafes or coffee shops in whatever location happens to be most convenient that week, be it Oxford, Banbury, or further afield.  We feel there are many advantages to this way of working: it allows a great degree of flexibility, the variety of locations we work in gives us inspiration and keeps us fresh, and there is no daily commute!  Meeting up as a team for just a few hours a week means our meetings have to be focussed and efficient.  Therefore when we do get together in the same room we can each bring bags of energy and ideas, and we have found it the perfect atmosphere for intensive brainstorming sessions.

Creative energy

Earlier this year the CNA team had a great opportunity to apply some of the principles behind the inspiring housing schemes in Clare’s book to a design of our own.  The proposal was for a housing development in Cambridgeshire on the site of an old farmyard.  The development would be intended for young families, moving out of the city to a more rural location to settle down.

The proposal required a sketch scheme to be drawn up in a very short space of time, and therefore a different design process to our usual way of working.  Normally CNA proposals are the outcome of conversations with our clients, followed by carefully thought out designs tailored to their personal requirements.  Only one or two team members will be working on a particular set of drawings at any given time.  In this case however we were working to produce a more general design, and very quickly, which called for a giant collaborative brainstorm!  Getting our coloured pens and tracing paper out over the table together meant we could bounce ideas off each other and come up with something we were all happy with at a very fast pace, not to mention having fun at the same time!

contemporary vernacular housing development

An overview of our imagined scheme in Cambridgeshire

Although CNA will not be taking this project further forward, due to the rate of delivery required by the developer, our sketch proposal stands as a great example of the benefits (and enjoyment) that come from short but intensive collaborative design.

September 1, 2016

AECB Conference 2016

Anne Thorne Architects straw bale house

Fran’s strawbale house

The AECB conference 2016 was held at the UK’s greenest building – The University of East Anglia Enterprise Centre designed by Architype. The most exciting thing for me was that the walls are clad in thatch (a vernacular material) and that all materials were sourced as locally as possible. When designing buildings, there is a lot of focus on keeping energy bills low, but not so much on keeping embodied energy low. Embodied energy is the energy required to manufacture and then deliver the product. Today we can import materials from anywhere, in stark contrast to the vernacular builders of the past who would have been limited to their local area. The latter is far more sustainable, but often overlooked as a necessary part of eco-building. The Enterprise Centre also achieves Passivhaus levels of comfort and air quality. It is a beautiful building, proving that eco design need not be ‘wacky’, it can fit well if it is well designed.

I learnt a lot from Bill Butcher of Green Building Store’s talk about their latest deep (meaning very eco) retrofit of a house in Cumberworth, West Yorkshire. The owners had been paying £3000 a year just on heating (not including wood burning stoves) and were freezing, on this exposed Yorkshire hillside. Having come into some inheritance, they decided if they wanted to stay put, something had to be done. So they enlisted GBS who have achieved a 67% reduction in their heating requirements. GBS used a combination of capillary active Tectem insulation, fibreglass and a new product called Diathonite, all internally. The airtightness result (2 air changes instead of 1) was not as good as they were aiming for. Bill said this was because they should have treated the partition wall as an external wall.

David Gale and Tomas Gartner from Gale and Snowden Architects launched the new Building Biology course in the UK. This teaches practitioners how to mitigate the effects on human health caused by radiation, dust, off-gassing from synthetic materials such as MDF and plastics and alternative materials to use in construction that will not create problems. Our indoor environments have a huge impact on our health including allergies such as asthma.

Fran’s straw bale house

AECB conference 2016 straw bale houseA great highlight of the AECB conference 2016 was a visit to Fran Bradshaw (of Anne Thorne Architects),  house in Norfolk. It is Contemporary Vernacular Design at its best, with locally sourced materials (even the reeds for the thatch which due to poor water quality in the UK, often has to come from abroad), and a design that is a contemporary interpretation of a thatched cottage. Using renewable and low embodied energy materials (timber frame, straw bale walls, roof insulated with thatch, cellulose (recycled newspaper) and wood fibre board) it is also an eco-house in the truest sense. The house also very nearly achieved Passivhaus, showing how energy efficient this way of building can be. it is a brilliant example of how to achieve a beautiful house and an eco-house. All of the AECB visitors agreed, this is the way forward.

I can’t wait to build my own straw bale eco-house!

Hemp prefabricated construction

Greencore Construction

I also attended a seminar by Greencore Construction on hemp and timber frame prefabricated construction. This was very fortuitous and perfect timing as my blog about a CNA visit to one of their houses describes.

Gary Wilburn, Director at HPW gave a talk about some of their larger projects, including a Peppa Pig tourist attraction and a shopping centre with restaurants at Rushden Lakes. While a bit controversial at an event about eco-building (do we really need another shopping centre/tourist attraction to enjoy these natural environments?), Gary’s message about methods of persuasion to clients not yet sold on the benefits of building sustainably was a good one. After all, these types of commercial projects are going to happen whatever we at the AECB might prefer. At least if there is a green architect whispering in the client’s ear, things such as miles of extra cycle paths, wind-catchers providing passive ventilation and removing the need for air-conditioning, use of renewable energy sources and renewable materials as well as wildflower roofs will mitigate the overall environmental impact.

August 30, 2016

Hemp, Lime and Timber Frame Prefabricated Panels

Greencore construction

 

 

Hemp, lime and timber frame prefabricated panels are an exciting way of creating eco-homes. I recently visited a ecohouse (that doesn’t look ‘eco’) completed in August 2016 and built by Greencore construction and was given a guided tour by Julia Bennett and Ian Pritchett.

Prefab or craft, can you have both?

Having written a book on Contemporary Vernacular Design, I am very keen to retain craft skills as much as possible. However, as part of my book research, I interviewed architects Alan Dickson of Rural Design and Neil Stevens of Dualchas, both situated on the Isle of Skye and both producing beautiful contemporary vernacular dwellings, well suited to the tough conditions in the Highlands. What was intriguing to me was that both firms provide their own pre-fabricated dwelling options (coming under R-House and Hebridean Homes respectively) in addition to their usual bespoke dwelling design. These still look beautiful, and as Alan Dickson explained; there are 101 ways to get timber cladding wrong and one way to get it right, pre-fabrication is a way to get it consistently right. These prefab houses look beautiful and crafted.

Inspired by this, I have been keen to explore pre-fabricated construction to reduce time and worry on site (especially with Passivhaus builds). Which is why I was so pleased to attend the Greencore seminar at the recent AECB conference in July 2016. (strange how you have to go all the way to Norwich to discover what you need is only on your doorstep in Abingdon!)

Having provided the hemp construction system for The Triangle, Swindon (link), which was not prefabricated and built on-site during the cold and wet winter of 2010-11, Ian Pritchett could see that prefab, where panels are built in a dry factory, had to be the way forward (having been a doubter himself).

The natural prefab panels

Hemp, lime and timber frame prefabricated panelsGreencore offer a timber framed, hemp-lime filled, factory-made panelised system. But this is not SIPS – which is high in embodied energy, not breathable and studies in America have highlighted issues with poor airtightness detailing causing internal rotting. The hemp and lime lock up carbon and are both renewable and breathable offering a superior living environment. Greencore offer a bespoke design, working with architects at an early stage to ensure that design and construction are in synergy and there will be no surprises on site (or at least they are vastly mitigated – there are always surprises on site).

Commercially viable…

Ian is keen to point out that although you can use clay or lime plasters internally to complete the full breathability of the wall (and therefore a lovely atmosphere as well as very low environmental impact). You can also use standard plasterboard and emulsion paints and that these more commercially viable materials will still offer a pleasant living environment when combined with an MVHR system. I was surprised to discover a lack of fresh paint smell and assumed eco-paints had been used, but no, standard emulsions and an MVHR ventilation system delivering constant fresh air allowed smells to disperse very quickly.

Lots of light in a hemp prefab house

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The house is simple in design, with an attractive L shape, lovely open plan spaces, lots of light and beautiful vaulted ceilings with large rooflights in the bedrooms and bathrooms.

Simpler to achieve Passivhaus detailing…

Unlike the wide masonry cavity wall Passivhaus construction that I have previously used, the hemp-lime timber frame construction is easier to build in many ways. Windows are best situated in the middle of the insulation to retain best thermal performance and this can be achieved by sitting them on plywood boxes in masonry cavity construction, however stone reveals are not possible and aesthetically clients are not so keen on the deeper external reveals. The hemp-lime system allows you to position the windows centrally without ply-boxes as that is where the timber frame is situated. However, to fulfil client expectations (and this house is a commercial project), Greencore have used pure-nit boards to cantilever the windows closer to the external face of the wall. Purenit® boards, though more expensive than plywood offers much better thermal performance.

Using PHPP (Passivhaus Planning Package) software as standard they are able to predict heating requirements and always beat the predictions of the software on site. This means that the performance of hemp-lime beats the predictions of the PHPP and the heating demand is lower once built than was predicted by the software. This is very advantageous and defies the industry norm of as-built energy performance being lower than predicted in SAP (the industry standard for assessing energy performance of building as required by building regulations for all new buildings).

I am looking forward to working with Greencore on future projects.

 

 

August 30, 2016

Contemporary Vernacular Housing Book out!

My new Contemporary Vernacular Housing Book is out in November!

Contemporary Vernacular Housing Book

My new book, Contemporary Vernacular Design – How British Housing Design can Rediscover its Soul will be available in November 2016. It is available to buy using the link below.

After two years of visiting case studies in the UK and Europe, my Contemporary Vernacular Housing Book has finally gone into production with RIBA Publishing. These two years were challenging because the research involved visiting case studies, interviewing residents, architects and developers or housing associations as well as writing and editing. During this time I was also running a busy practice and teaching a day a week at Oxford Brookes University. The book also contains 5 case studies from further afield, researched as part of my masters thesis. Julia Phillips (architectural assistant at CNA) helped me  with editing and organisation of the book and Katie Reilly (architectural assistant at CNA) gave me useful feedback prior to submitting the manuscript when I was too tired to read another word!

The research has been hugely rewarding and I have met some wonderful architects as well as inspiring housing associations and developers. This research informs our work at the practice and is very much a part of our ethos.

I am also excited to announce that architect Piers Taylor (of £100k house: The Final Fix TV series and founder of the Invisible Studio Architects), is currently writing the foreword.

Buy here

August 20, 2016

Barn use classes & ‘agricultural unit’ clarification

Barn use classesBarn use classes

I have received queries recently about certain elements of permitted development for barns. The first is about how existing barn use classes affect the permitted development. A current project helps to explain this. Two neighbouring barns, each is to be converted for residential use, have slightly different prior approval permissions.  The difference is actually quite minor, and lies in the barns’ original use classes.  One barn conversion is permitted under Class P (change of use from a storage or distribution centre to a dwelling house), and the other falls into Class Q (agricultural buildings to dwelling houses).  Both of these Change of Use Classes have a cap on the area of building that can be converted – for Class P it is 500m2 and for Class Q it is 450m2.

This brings me onto the second query on this subject, which was to do with a Class Q conversion. The official wording states:

Agricultural buildings under 450sq m are permitted to change to Class C3 dwellinghouses, together with some building operations necessary to facilitate the conversion. This is subject to meeting certain criteria, including no more than 3 dwellings within an agricultural unit.

So what constitutes an “agricultural unit”?

The General Permitted Development Order defines an agricultural unit as:

agricultural land which is occupied as a unit for the purposes of agriculture, including— 

(a) any dwelling or other building on that land occupied for the purpose of farming the land by the person who occupies the unit, or 

(b) any dwelling on that land occupied by a farmworker.

This is quite an open definition, the main gist of which seems to come down to whether the buildings and land in question are all a part of the same business enterprise.  For some projects this definition is very straightforward, whereas for others it can be a little more complicated and the boundary of the agricultural unit may not be so clear.  In case of doubt it is best to consult a local authority planning officer.

written by Julia Phillips – architectural assistant at Clare Nash Architecture

June 3, 2016