Friday, 20 November 2020

Pegboard Kitchen

Pegboard panels are a very versatile way to transform a space.  Here we took a small kitchen in a holiday let and gave it new life as a fun, playful space.  The same ply was used on the base unit fronts, with pegboard accessories used as handles.  A variety of lighting compensates for the lack of direct natural light.  Happy cooking!!

Pegboard and by Kreis Design
Installation by Steven Shaddick Building & Maintenance

Wednesday, 28 October 2020

Regenerating Scotswood

Trans on Scotswood Road. On one side are shops and houses. 

On the other side are the railway line, river and the factories 

of Vickers, Armstrong’s for shells and tanks.

I uncovered this note from my late Dad describing life as a young child in the Scotswood area of Newcastle in the late 1930’s.  The area was adapting to rehousing, changing communities and social engineering.  Although this was more than 80 years ago I believe many of the expectations and aspirations of the residents are still of value today.

The Scotswood area started to the west of the Central Station and Scotswood Road ran along side the River Tyne until it reached the Scotswood Bridge.  It was a long road that I remember walking when we visited my Aunt’s house.  It was long, busy, black sooted but had some good shops and lots of pubs.  My Aunt lived in the back to back houses that stretched from the Scotswood Road up to the steep banks of the Tyne towards Elswick and Benwell.  Elswick, Benwell, and a bit further up the bank, Wingrove and Stanhope Street were a bit posher than the areas of Scotswood.  However, some of the houses in Scotswood dated back to early Victorian times and boasted cellars, an imposing entrance up a number of stairs, big windows and big rooms.  My Aunt by comparison lived in a small ground floor flat with a living room, a kitchen and two bedrooms.  There was no bathroom; the lavatory was in the back yard next to the coal house.  Lighting was by gas and in the evening the lamps hissed above the general conversation.  My cousins were noisy and street-wise.  They had black hair like their father and were dark skinned.  Uncle John was fierce and tough and stood no nonsense from the neighbours but was always ready to help if there was anyone in trouble.  He was a great union man and capable of nicking anything left lying about.  Scotswood was a bit like my Uncle John; tough, without airs and graces, fierce in defence of his beliefs and a bit suspect when it came to living by the law of the land.  

My family was moved by Newcastle Council from Elswick and with other families from Scotswood were given new homes on the Blakelaw estate next to the northern parts of the Town Moor.  The house had an upstairs and downstairs, a living room, scullery with a pantry, three bedrooms and a bathroom.  It had a garden at the front and at the back which were roughly marked out by wooden posts and wire.  It was 1938 and we had electricity!  All of our neighbours were new to us. None of us had moved with people they had lived closely with in Scotswood.  We were from the Elswick area, top of the West Road bank from Newcastle’s Snow Street.  We thought we would know some of our new neighbours but we didn’t. We were a new community that had to get along with each other in our cul-de-sac of houses in Murrayfield Road.  We were a motley lot.  Some found adjusting to the new houses very hard.  Our immediate neighbour was a rag and bone man.  He housed his horse in the scullery until the Council found out.  Bugs from the heaps of old clothing he piled up outside his back door began crawling along the back walls of the houses.  I had never seen bugs like those before.  Adjusting to having a front and a back garden was a novelty for the residents.  Agreeing the extent of each patch and keeping them cultivated and tidy became a new focus of communal attention and  contention.  Another change was the lack of shops.  A lean-to hut and a house converted into a shop were the only facilities for the whole estate.  These were located at the far end of the busy Portland Road which was a hike for both adults and children.  A Co-Op existed even further away in Cowgate.  We attended Cowgate School near Fenham which was another hike each day. The Council improved housing but neglected community amenities in their plan, especially for the kids. 

The Moor was a great boon for us.  Its space and freedom were something novel, and we enjoyed it.  As a gang, the children of Murrayfield Road discovered that over the Moor, in the South Gosforth ‘posh’ houses, there was a small park with swings and a slide.  We trecked there for a while and enjoyed the playground until we were chased off by the South Gosforth residents.  Acceptance of the community did not come easily, after all they had come from Scotswood!  Even on public transport there was a separation social groups.  The No. 4 bus to the centre of Newcastle was always crowded.  The No. 5 service to Newcastle ran on the same route but the closest stop was outside Blakelaw which missed out our estate. You paid more on this bus and it was used by people from Ponteland and Darras Hall.  

Newcastle Council were recognising that they had to address the amenities of our estate when the war came along and all plans were shelved for 5 yeas.  Apart from a new primary school, change was slow.  The community had gelled well but self help was expected. 

Later, in the 1950s, more people from the Scotswood were decanted in to the Montague Estate and Denton area and the new residents seemed to experience similar issues of cultural  change as us.  Money was scarce, the post-war years were lean and Newcastle council at that time was not really tuned to think of community assets to attract residents to the area.  

The original community of Scotswood was tough.  It was not always pretty, but it was alive and vital.  Planning and action by the Council tied to breathe life in to the Scotswood community with improved housing, but also in the process, a re-engineered community culture and controlled social hierarchy.  I wonder how much of what they delivered to this community was working for the community’s benefit.  

July 2007

Friday, 16 October 2020

Finding Form: Using Paper to Realise Architectural Ideas

Working regularly with children and school groups running architectural workshops, I use techniques on paper folding and paper engineering.  The work involves investigating design in 3D to help develop spatial cognitive skills. Folding paper and card helps develop children’s dexterity and the fine motor skills in their hands, which is something easily neglected with the use of iPads and games consoles. The workshops regularly take the children’s design ideas and scale them up to full size with large-format corrugated card and plastic, so the students can experience their creations full-scale.

Products of a design workshop in the Design Technology 
department of Graveney School, London SW17

I think working with paper in this way identifies a gap in the architectural work-flow for professionals as well as being a study focus for school workshops.  Architects don't really play with paper and card to test 3D ideas.  Too often it’s done through 2D or 3D computer models.  UCL's 'Fabricate 2020' conference this year addressed a wealth of computer technologies, parametric software, rapid prototyping and CAD-driven machinery.   Foster & Partners are also investing significantly into large-format 3D printing.  We're handing over our creativity to AI.  The human brain and hands are more sophisticated and articulate than any software or machinery.  A goal of this post is to encourage architects to ‘play’ with paper and card more freely.

Play is the highest form of research - Albert Einstein

I normally work with school students in local authority schools where resources are limited.  Simple paper and card is hugely effective and gets quick results.  I aim to 'lead' the workshops with examples and pre-made kits but the emphasis is on experimentation and play.  It’s not long before they flip the script and student’s creativity takes over.  What children have in imagination out-strips anything I can offer in design experience.  They unpack what experienced designers consider normal or take for granted, and re-structure the work in ingenious ways. 

My enthusiasm for this hands-on paper-based approach to 3D design led me to reach out to Paul Jackson, a world-renowned origami artist and author of over 40 books on the subject.  We discussed the subject and he offered lots of advice on teaching methods and workshop exercises, to get the best results out of this working method.  His advice was very insightful, offering a lot of strategies to work with in the classroom.  Paul said:

There are many reasons to want to manipulate paper, and many methods to work with.  Folding and cutting are the two most basic mechanisms and are creative opposites: Folding makes a sheet smaller and cutting makes it bigger.  This expanding and contracting are two sides  of the same coin but do very different things with the paper.  Folding is geometric and a controlled process.  Cutting can offer a lot more freedom creativity but can be without the same discipline and control as folding.  Paul focuses on folding as it offers more creative control and is a reversible process, which cutting is not.  

Playing with variations on one of Paul's standard folding motifs.

Secondly, start with the reasons for wanting to fold.  Is it to create a structure, a shelter, a pavilion, a bag to piece of furniture?  This should be the starting point of the process.  From there, let play and experimentation drive the investigation to see what the paper offers through your mind and fingers.  

Paul often begins workshops teaching  generic folding techniques.  These are outlined in his books and offer many many possibilities and applications.  Using A4 paper makes work simple and accessible.  Students are less concerned about making mistakes.  Trial and error is important.  The process involves making a mess in the classroom; creating a large body of studies from which the more successful examples can be extracted to form a vocabulary of 3D geometries to develop design proposals with.  

Developing variations on standard folding motifs

This process gets students working three dimensionally, realising studies they can hold in their hands and developing their understanding of 3D geometry which they can then apply to multiple applications.  It’s a process which also seems to work for different design subject areas such as Architecture, Sculpting, Textiles, etc., because the basic principles are transferrable.  Improvisation is an important part of the workshop process because the design sequence will always be different and individual; creativity unpacks what we think we know and offers new possibilities for achieving the design goals.  

Some other very simple exercises include the use of post-it notes.  Asking the students to make one fold only in the sheet might not seem too creative, but assemble them in sequence in a grid and they can transform in to am impressive composition.  Examining the pattern with changing light adds to the dynamic and can be really exciting.  

Options on the theme.  Even crumpling a sheet makes a versatile

Paul says that a simple fold offer more design possibilities than complicated folds.  They can be used in many applications.  Two to three folds can offer a great base for creative design.  Start simple and play.   Test the designed forms in changing light and the environment of the workshop.  

Simple folds establish modules, units, simple patterns and folding motifs which can be arranged in a variety of ways and at different scales to create a huge variety of forms.  Experiment with variations on the same pattern; repositioning nodes, angles of folds and changing the shape of the paper etc.  This offers yet more variations and possibilities.  Different arrangements achieve entirely different forms and results.  

Paul’s advice is to keep the investigation simple and work up to a level of complexity comfortable with the class.  It’s a visual and tactile process that enables students to understand 3D form directly like no other activity - but play is a must:  Play play play!  Paul adds that origami might have been around for thousands of years but there are novelties, new discoveries and new creations that emerge with every investigation.  

Translating folds in to sheet patterns to create pleats and structures

There is something magical about taking a piece of paper and from a starting point of nothing, creating a form, structure or an object with your hands and a few quick folds.  Paul describes it as modern day alchemy.  It's also a reversible process which can transform between one state as another, something which is unusual and special in creative processes.

There is nothing in a sheet of paper that suggests what the form is going to be before it is folded.  It is usually very difficult to visualise a resultant 3D geometry from looking at a folding pattern.  This is a learnt skill. We are not born with it.  We are used to 2D and 3D patterns and forms but we are not trained to perceive the transition between the two.  Perhaps because this needs to be learned we find it easier to rely on computers, CAD, parametric software and 3D printing etc.  But automation and digital technologies are not the same as having something that you can create, hold in your hand and manipulate from one stage to another.  This is not something achievable with 3D CAD.  Computers produce one item at a time and these are not immediately accessible as items you can hold in your hands.  

For primary school pupils, paper folding is important for developing fine motor skills and dexterity in the children’s hands.  Muscular strength required to hold a pencil with early years classes could run in parallel with basic origami skills.  

For architects and design professionals it should be second nature to have a stack of paper to hand by the desk, to enable design issues to be investigated with folded paper exercises.  

For me, this makes workshop planning more focused and efficient.  I look forward to testing these principles out in the classroom soon, when restrictions allow. 

Paul Jackson and his work can be found at:



YouTube:  (Although Paul stresses that books on the subject are a much better source for ideas and learning skills) 

Monday, 27 July 2020

Architecture runs on STEAM

Architecture involves just about every subject in the National Curriculum. It is not limited to STEM subjects and relies as much on arts based and practical subjects to create balanced results.

Architecture demonstrates that it’s important to have a full spectrum of subjects for creativity.  Subjects are important in themselves and in integration to support design and architecture related disciplines.

Architecture demonstrates the importance of the full spectrum of
academic subjects; individually, integrated and from the connections in between.

STEM subjects (Science, Technology, Engineering and Maths) promote left brain thinking.  They are important objective subjects but often teach us how the world is supposed to be, rather than prompt us to consider how it could be or challenge the knowledge.

STEAM subjects include The Arts, adding creativity, subjectivity and a challenge to what we think.  This is important for adding depth and additional dimensions to the more objective subjects.  It can present a challenge to our thinking and make some uncomfortable departures from our comfort zones, but the results are worth it.  It's a key component to innovative and creative thinking.

A full spectrum of subjects, including practical courses, are important for creativity.  This allows thinking around problems and realising solutions which would otherwise prove difficult to unlock.  Young minds are diverse thinkers And incredibly creative which is important to recognise and encourage.  Education can help train the mind to harness and develop that creativity.  This makes it important to support STEAM subjects in education and promote connections between each subject discipline.  Art based subjects help us to question, conceptualise, visualise and describe our thoughts, not just illustrate them.

Sunday, 5 July 2020


DesignBox Architecture with Graveney and Glenthorne Schools are delighted to have been shortlisted for the Empowering Platforms competition held by the London Festival of Architecture, with Westminster Council.

The competition called for proposals to reimagine the experience that people have with the River Thames along the Westminster north bank:  A design centred around inclusivity and accessibility, creating a stimulating experience at the river-front for all.

Our proposals sought to capture the imagination and creativity of secondary school students with a response reflecting the cultural diversity and ideals from the students, our next generation of London citizens.

With the student team we developed 'YouScape'; an urban outdoor garden library.  It's a place to sit and relax and escape from the pressures of London.  It is designed to be a simple platform to connect to nature within the heart of London and engage with literature.  An oasis within the city.

Site investigation, design considerations and brainstorming

It is designed as a catalyst for community involvement, to draw people to the installation to engage with others and read a book, surrounded by greenery.  Relaxing in the installation, people can observe the passage of time, watching the activity on the river and passers-by.  A screen with planting and a wall of books separates people from the noise and bustle of the traffic behind.

'Put your feet up and read a book' was a key reaction to the site from the student team.

Initial concept ideas and MoSCoW analysis

The concept was developed to capture the scenic river views whilst isolating people from the noise of the city.  The project seeks to capture light and encourage the growth of plants, to help make it an engaging and interactive installation for everyone.  

Student concept perspectives

The selection of materials examined the practicalities of the surfaces required with opportunities to introduce colour and light into the installation.  The team selected plants which are ideal for horizontal and vertical surfaces, require little maintenance and can be easily trained.  They were identified for their variety of types, colours, flowers and even fruit.

Materials for practicality, durability and fun

Planting selected for variety of type and colour, and for ease of maintenance

The proposals were drawn up in CAD to create a measurable set of drawings for discussion with suppliers and fabricators.  The team discussed the advantages of simplifying the range of materials and number of assembly processes to enable a simple procurement route with as few supply chains as possible.  This was of increased importance in the period of social and economic lock-down because of Covid-19.

Plans, sections and elevations of the proposals for
discussions with suppliers to resolve price
and programme issues

The proposals involved a stressed skin structure in timber and polycarbonate sheet.  Each component performs several tasks.  The structural frame doubles as the book case and the polycarbonate sheet stabilises the overall enclosure and let light in.  The installation is self-supporting and can sit on rubber levelling mats, set directly on the pavement.  The installation is designed to be as simple as possible so it can be fabricated by a joiner or general builder and assembled by the student team.

Structural developments in discussion with a Structural Engineer at Price & Myers
and with feedback from timber fabricators

The proposals included solar cells with localised batteries to supply power for lighting.  A small back-up battery similar to that used in EV vehicles was proposed to keep the overall system energised.  This could be topped up periodically either by a portable charging system or swapped out for a fully charged unit.

Low energy LED strip lights concealed within the flange of the ribs were selected with colour temperature gradients to work with the changing colours of natural daylight.  An integrated photocell allows the lighting to respond to natural daylight patterns.

Services developments kept simple to be easily managed.  Proposals developed with AECOM.

The budget for the installation was £20,000+VAT, which was to include a nominal design fee of £2,000+VAT.  This left £18,000 for fabrication, installation, one relocation during the LFA 2020, maintenance whilst on site and removal at the end of the festival. With a Quantity Surveyor, we worked back from the logistical and site requirements of the project and determined that £12,000 was available for materials and fabrication to achieve the proposals. 

Exploded Isometric:
1 Structural ribs,
2 Bracing,
3 Flooring with anti-slip surface,
4 Central tower book case
 5, Rear wall book case,
6 Metal grid for training plants,
7 Polycarbonate coloured transparent roof

The proposals considered that the installation might be fabricated off-site, transported to site and lifted in to position as a single unit, with lifting eyes similar to that of a 20ft ISO container.

A place to sit, relax and read a book and engage with nature
in the heart of London

We are all stakeholders in the design of our surroundings.  YouScape, designed by our team of secondary school London students demonstrates this.  We hope that the proposals demonstrate how we all can take a greater role in working to create a more inclusive, accessible and cohesive environment.

Value engineering: Investigating options with geometry,
materials and fabrication methods to reduce costs

Discussions with suppliers identified that the curved geometry was adding a premium to the price and exceeding the budget.  The team discussed options to reduce costs without compromising the concept.

Amended scheme to meet the competition budget

The value engineered option is designed to save costs by replacing the curves geometries with faceted panels, sizing all items to work with full 8'x4' ply boards, and fabricating the installation for flat-pack assembly so it can fit into the back of a large luton van.

Value engineered scheme, exploded isometric:
1 Four base panels bolted together,
2 Six rear panels,
3 Two panels bolted together to form the lower walls,
4 Two panels with polycarbonate roof to form the upper walls on each side,
5 Central book case tower,
6 Four panels with polycarbonate sheets to form the roof

The process of working with the student team was thoroughly enjoyable and enlightening.  As our next generation of London citizens, the values and insights they brought to the project, along with commitment and collaboration was a delight to experience and work with.  We produced a very exciting and achievable design proposal despite the restrictions we worked through.  The student team was brought together in the first lockdown of 2020.  We raised the team from volunteers, reaching out through the School's Google classroom platform and we never actually met face-to-face to work on the proposals.  The project progressed through a combination of daily Zoom meetings and emailed files.  I am extremely proud of the team, firstly for rising to the challenge and secondly, for persevering through these difficult circumstances.  I'm told they thoroughly enjoyed the process and I worked to allow the students to lead the design conversations and have fun with the design.  

In addition we had assistance from the industry specialists listed below, which gave the zoom discussions an additional dimension and grounded their proposals in reality.  I understand that one student now wants to pursue a career in architecture and another in design-based engineering.

Professional Design assistance:

Structural Engineering: Price & Myers, London

Services and Sustainability Engineering: AECOM

Cost Consultant: Morham & Brotchie (Oban)


Buildability assistance:

Phil Cooper, Cooper Joinery & CNC Services

Michael Acey Furniture & Bespoke Interiors


A professional Architectural drawing class was presented by Phil Buckingham: Drawing Classes for Architects.  The class took place over Zoom and focused on interior and exterior perspective techniques to help the students develop the proposals.  


By Chris Curtis,, developed from the student’s drawings.

Our scrap-book of ideas which we used in the design discussions can be found on our Pinterest page.

I hope there will be an opportunity to repeat the process with another competition soon.

Thursday, 4 June 2020

A Window to the Future (in a nutshell)

I asked my son for a list of things he had seen on the internet which interested him.  It was partly to get an understanding of what makes him 'tick' now that he is 16 and shaping his own views of the world.  It was also because the interests and values held collectively by our next generation of adults will shape the future of our business and industries.

This is the response below with his notes:  A set of nine youtube clips mostly about technology, economics, health and the future of our nations. 

How we can harvest the energy of the sun on a galactic scale and push onto the next level of civilisation:

How we can use the energy of the sun and move the whole solar system in any direction:

In-depth explanation of the recent pandemic:

How we could utilise this as antibiotics become obsolete:

Infusing glass with uranium to create luminescence: 

How we could turn a black hole into a bomb hahahaha:

Information on the EU:

The moral discussion of whether to allow robots to have rights as humans:

Where valuable minerals are created and the conditions needed:

It addresses an ambitious set of ideas which reflect the areas of technology we are entering in to now, including GRAIN (genetics, robotics, artificial intelligence and nano-technology) supported by Tier-0 technologies, and beyond with astrophysics and energy creation.

I thought it was a neat little exercise and might prove valuable as a wider student study to form a perspective on the valued held by our younger generation and what the world might be like in the future.

Sunday, 10 May 2020

Innovations with Building Materials

I wrote a literature review on the innovation of  materials in the building industry some time back.   Then period architecture, especially Victoriana was considered more desirable than contemporary builds in popular culture.

Meanwhile, the rest of the world was on the start of a technological wave involving the internet, information technology and world wide communications.  The innovative products of this were conspicuous in their intent to introduce us to their brave new world.  By comparison, innovations in building materials were often hidden behind more familiar or traditional materials with reference to the past.  Other industrial sectors such as aircraft, train and car manufacturing appeared more confident about displaying a design aesthetic which marked their place in the present, looking forward.  

With the current generation of technological innovations progressing with the involvement of A.I., automation, genetics, 5G networks and nanotechnologies, it is worth taking a look at the position of the building industry in this context, to speculate what the affect might be on Architecture. 

Barriers to Innovation

Barriers to innovation arise from the balance of the relationship between producers and consumers.  The products of this relationship provide evidence of how innovation is managed and tells a lot about the producer / consumer relationship.  Back at the turn of the century, there was a strong reliance on design as a tool to reinforce the values of known materials rather than experimenting with the possibilities of the new.  There were and have been since, lots of innovations in building materials and building systems, but the finishing layers usually default to a familiar material with a commonly held value, with the innovation hidden behind.  There are many excuses that might be given, such as a building has a long design life so designing it to fit in to a known period style is safer than exposing innovation that might look dated in years to come, and innovative design presents a risk because new building systems can fail with serious consequences, but I believe the key issues lie within the structure of the building industry which and its knowledge and understanding of its consumer base and stakeholders. 

The building industry is very fragmented with a lot of independent business entities involved.  Clients appoint Architects to represent their requirements and aspirations with aesthetic designs.  Architects also have one eye on their position within the Architectural profession and standing with their peers, PI insurance, resource schedules and project risk assessments.  Other design team members are similar.  It is difficult to establish an integrated and cohesive R&D programme to a relationship which gathers for one project over the course of a year or two, then disbands.  Instead, design is used as the key tool to balance functional requirements and aesthetic aspirations, largely with materials and building systems available to the industry; products developed specifically by companies to ensure a successful uptake. 

Innovating with building materials

Knowing the market place and the customer base is a key item.  Typical examples where bold innovation has changed societies and industries are often characterised by single businesses which have carefully controlled their innovation processes and managed their risks to achieve great results.  The public face of these companies looks simple and understandable, even though the processes and supply chains behind are not. 

Brand value and standing within the market place reportedly accounts for a lot of credibility with the public.  It is hard won and easily lost, but represents customer loyalty and trust.  With the public's engagement in a company brand, the risk associated with bold innovations can be greatly reduced and more effectively managed. 

Opportunities for Innovation

Developments in technologies are progressing at an ever increasing rate and we are on the verve of a next wave of changes to society with Tier 0 technologies.  This will no doubt have an affect on the building industry with regard to how we design and produce buildings, how the services will operate, how they will be maintained and lots of stuff to do with what goes into them, but hopefully it will also mean more than a smarter way of producing a brick wall.  It's a chance for the building industry to catch up to other industrial sectors but for this to happen, it might require a new business model in the industry to present an integrated and cohesive offer; a Google or Netflix of the building industry.

Wednesday, 25 March 2020

An Introduction to Designing Facade Walls (or The Secret Life of Moisture)

Facade design can be a bit of a challenge.  Specific project requirements require different responses in design.  The basic parameters requiring consideration include:
  • Different building types,
  • Differences in functional and aesthetic requirements, 
  • Specifics of the local environmental climate,
  • How the building is to perform in relation to thermal mass, thermal resistance, air tightness and resistance to wind-chill etc.
One key performance factor is the behaviour of moisture within the building envelope, which if not designed out thoroughly could lead to deterioration of the building system and rot.  The secret life of moisture in external building envelopes is something I wanted to investigate further, so with the help of Will MacDonald, Head of Facades at AECOM, we have the following answers to unlock how how it all works.

Looking at moisture:
Water vapour in the air condenses on to the face of a cold glass of water, when the temperature on the glass reaches the ‘dew point temperature’; the temperature at which air can no longer hold all the water vapour which is mixed with it, and forces it to condense.  The dew point temperature is always lower or equal to the air temperature.  Water vapour particles hit the surface of the glass and stick instead of bouncing off.  

The amount of condensation created depends on the amount of water vapour in the air, temperature changes and the dew point.  Condensed water has to evaporate again which depends on the temperature of the water in relation to the temperature of the surface it is on.  Therefore, condensation depends on temperature and moisture content, while evaporation requires temperature, as long as the relative humidity of the surrounding air is less than 100%.  If cold enough, the condensation becomes frost.

There are two types of condensation in buildings: 
  • Surface condensation, found normally on an internal or external finished surface, and 
  • Interstitial condensation which occurs between the layers of the building envelope; inside the composition of roof, wall or floor build up.  
Adequate protection and ventilation os required to reduce the risk of moisture causing problems within the building fabric.

Surface condensation depends upon the surface energy balance of the building and the moisture content of the ambient air.  A higher level of insulation increases the risk of condensation on building facades in humid climates, especially in humid climates on clear nights where maximum heat loss occurs.  The risk of micro bacterial vegetation (algae) can accumulate on surfaces.  Variables affecting this include:
  • Internal vapour transmission,
  • Thermal gradient and level of insulation, 
  • Heat transmission and sky emissivity

So what happens to moisture when it migrates in to a building structure?  These are Will’s explanations of how moisture content can be controlled with facade design: 
There are two main sources of moisture that have to be considered when designing a façade. These are: 
  • Water from the external environment, usually in the form of rainwater, but may also include the diffusion of moisture from a wet surface, and,
  • Moisture vapour diffusion. 
In temperate climates such as the UK, the air inside the building usually contains more moisture than the air outside. Therefore, moisture vapour will tend to migrate outwards through the building envelope. 

Water penetration resistance: 
There are two main approaches to water penetration resistance:
  • Face sealing, otherwise knows as a curtain walling system 
  • Secondary defence construction, otherwise known as a rainscreen system 
Face sealed systems rely on the outer skin of the construction alone to prevent water penetration. If there is any moisture ingress past the external skin, there is usually no provision to allow the water to drain back to the outside. 

An alternative approach to water penetration resistance is to provide a secondary defence rainscreen. This usually takes the form of a cavity behind the external face of the wall. The cavity allows moisture that ingresses through the external face to drain back to the outside through openings in the outer surface. The cavity may also have sufficient capacity and openings to allow ventilation, for increased moisture removal. 

A drained and/or externally ventilated cavity may also be beneficial in the removal of any moisture that migrates through the wall from the warm moist internal environment.

Classification of air cavities:
Air cavities may be classified according to a number of different factors. These include the position of the cavity in relation to the main insulation layer, and the size of the openings in the outer surface. 

Cold cavities: 
Cold cavities are located to the cold side of the main insulation layer. Because they are cold the moisture content should be kept low to reduce the risk of condensation forming. A vapour control layer (VCL) on the warm side of the insulation will reduce the moisture ingress in to the cavity.  They should be ventilated to the outside to remove moisture and keep moisture level close to the outside levels. 

The following classifications are taken from BS 5250: 2002 - Code of practice for control of condensation in buildings: 
  • Vented air space cavity or void is that which has openings to the outside air, placed to allow some limited but not necessarily through movement of air. 
  • An air layer having no insulation layer between it and the external environment but with small openings to the external environment shall also be considered as an unventilated air layer, if these openings are not arranged to permit air flow through the layer.
  • Drain openings (weep holes) in the form of open vertical joints in the outer leaf of a masonry cavity wall are not regarded as ventilation openings. 
  • A slightly ventilated air layer is one in which there is provision for limited air flow through it from the external environment by openings meeting a specific area. 
  • A well ventilated air layer is one in which the openings between the air layer and the external environment allows air circulation.
Warm cavities: 
Warm cavities are located to the warm side of the major insulation layer. The cavity surfaces will be warmer than those of a cold cavity and the risk of condensation very much less. A vapour control layer may still be required to the internal face of the cavity in order to keep it dry. 

Thermal resistance of air cavities:
A still air layer in a cavity construction will add to the overall thermal resistance of the element and improve its U-value. The contribution that the cavity makes will depend on the level of ventilation between the cavity and the external environment and the direction of the heat flow. 

The U-value of a cavity construction will vary depending on the type of cavity present, and its location with respect to the main insulation layer.   The values given by manufactures are generally 1-dimensional U values and therefore do not include the additional heat loss due to brackets, fixings and cavity ties that may be present in the construction. The constructions are considered to be vertical with horizontal heat flow. 

Notes on cavity construction: 
A cavity that is neither vented or ventilated presents a serious risk of moisture collection. For example, an insulating glass unit requires a hermetic seal and the provision of desiccant in order to remain condensation free.  The higher the level of possible ventilation in a cavity, the more moisture may be removed from it. Liquid water will be removed by drainage and evaporation.  Moisture vapour will be removed by diffusion and mass transfer. 

A fully-ventilated cavity will provide the most reliable means of removing moisture in the cavity. Air movements will remove moisture vapour that has migrated from the internal environment, encourage evaporation of any liquid water and promote drying of the cavity.   

A vented cavity will have less capacity to remove excess moisture. It relies on the diffusion of water vapour in the cavity. Its performance will therefore be dependent on the vapour resistance of all materials to the cold side of the cavity and the size of the openings between the cavity and the external environment. The lower the vapour resistance and the larger the openings, the higher the rate of transportation will be. 

The removal of moisture in a vented cavity may be increased by using a wider cavity. This will improve the air circulation by convection as there will be relatively lower frictional forces to resist the air movements. 

Internally ventilated cavities:
Warm cavities are not externally ventilated and might have openings to the internal environment.  This will allow warm moist air to pass into cooler parts of the wall.  Although this is a warm cavity, the surfaces will be cooler than those of the room, and therefore there will be an increased risk of condensation. 

The risk of condensation will be minimised if there are enough openings so that the cavity is fully ventilated to the inside. This will ensure that the surfaces of the cavity are as close as possible to the internal surface temperatures. 

Building Envelope Energy Transfer:
Energy is gained or lost from a building by: 
  • Radiation or convection from the outer surface of the building, and
  • Air leakage (mass transfer) into or out of the building. 

Energy efficient facades have to be insulated to keep the external surface as close as possible to the external temperature, be sealed to prevent gross air leakage (reduce mass transfer losses/gains), and shield internal surfaces (reduces radiation losses & gains from or to internal surfaces).  They also should allow sufficient daylight in to the building to reduce energy required for artificial lighting. 

Energy transfer mechanisms:
Conduction is the mechanism by which heat energy travels through solids and stationary fluids and gases.  Materials such as metals are good conductors while materials such as mineral wool are poor conductors  but are good insulators. 

Radiation heat transfer occurs because all bodies at temperatures above 0ºK emit heat energy. Two surfaces at different temperatures will emit energy at different rates and energy transfer will occur. 

In a layered construction all layers resist heat transfer but a layer that has a significantly greater resistance to heat flow is usually be specified as the insulation layer, to reduce heat flow through the wall. 

Heat transfer through a sandwich panel:
Assuming that a sandwich panel comprises a 120mm thick core of mineral wool with thermal conductivity of 0.035 W/mK and is faced on both sides with a 1.5 mm aluminium sheet with thermal conductivity of 160 W/mK, the heat transfer can only occur if heat is gained at one surface and lost at the other by convection and / or radiation (otherwise known as surface resistance).

In practice when a building element is exposed to the environments, the surface temperature on the cool side will be warmer than the air on that side.  The surface temperature on the warm side will be cooler than the air on that side.  These temperature differences exist and cause convection and radiation heat transfer at the surfaces.  It is possible to calculate the surface temperatures but it is more convenient to calculate heat transfer knowing just the air temperature on each side of the construction.  The thermal resistance for convection and radiation at each surface can be combined into a surface resistance measuring the total resistance to heat flow.  Temperatures through out a layered construction can be calculated from the resistance of each layer. 

Thermal bridging:
A thermal bridge occurs where a material or component of high conductivity pierces an insulating layer of lower conductivity. This allows heat to bypass the insulation with two effects:

1. The rate of heat transfer through the combined materials is greater than it would have been through the insulation alone, and
2. The warm surface is cooler and the cool surface is warmer. 

The second effect gives rise to the term ‘cold bridging’.  In cool climates thermal bridges cause localised cold patches on the inner surface of the building envelope and are associated with problems of condensation, dampness and mould growth. 

Isotherms are lines of equal temperature and these may be plotted to show how temperature is distributed through a construction system. 


Design principles:

Moisture is introduced into buildings through life processes such as heating, cooking, bathing etc.  Water vapour may be removed by natural ventilation or air conditioning, however, there must be water vapour in the air to make a room comfortable for habitation. 

Water vapour disperses through the air and migrates through porous solids in an attempt to give a uniform vapour pressure.  In the UK external air moisture contents are lower than internal levels and water vapour, which then  migrates outward through the wall.  For air-conditioned buildings in some warm and humid climates water vapour moves inward through the wall. 

Water vapour should not migrate past the first vapour control layer only to be captured by a second vapour control layer or a breather membrane which incorrectly acts as a vapour control layer.  

Cavities formed on the warm and humid side of a vapour control barrier may be affected by severe condensation. Cavities may be formed as part of the internal building fit out when window boards and internal panels are added. These will often provide insulation so that the cavity is cooler than the room but provide very little resistance to vapour movement. Solutions include ventilating these cavities to the room so that they are warm, and incorporating a vapour control layer to the inner wall panel such as a foil-backed dry lining. 

Rainscreen cavities should be ventilated so that any water ingress stopped by a breather membrane will dry out after drainage has removed most of the water. 
Two layers having a similar vapour resistance should be avoided.  A metal sheet might be perforated to avoid the creation of an unwanted vapour barrier and it might be necessary to provide a breather membrane to prevent external water ingress by-passing the perforated sheet. 

Mould growth on the internal surface is prevented by limiting moisture levels at the internal surface.  This can be achieved by ventilating the room or improving the wall insulation to raise the 
temperature of the internal surface.  BS EN ISO 13788 recommends that the relative humidity at the internal surface should be less than 80% to avoid mould growth. 

Condensation assessment:
Condensation assessment requires knowledge of the moisture contents and temperatures within a wall.  Building envelopes containing a single well-defined layer offering high vapour resistivity at the warm side of the construction can often be acceptable. For walls with no well-defined vapour control layer, or one that is in a cooler part of the construction, an analysis will be required. 

The behaviour of moisture:
Condensation occurs in the ventilation cavity and not on the outside face because the heat flow direction is from inside to the outside. The warm air in the cavity has a higher lever of water vapour and as it cools it forms condensation. The temperature difference is very small between the cavity and the outer face, hence no condensation.  On some well-constructed unitised façade system (front sealed) you can often see condensation on the metal spandrel panel.  

The higher the value of insulation, the greater the risk of condensation.  The value refers to heat flow of the material. The higher the value the more heat will be lost. As more heat is lost you will get more vapour changing to liquid, promoting a risk of condensation.  The condensation isotherm lines change with the different value of insulation.  Good practice with rainscreen design recommends these lines are kept within the cavity.

Looking at different cladding systems and why those used in Antarctica are different to each other, and different to solutions of other climates:
Interstitial condensation a risk of material breakdown with the build-up of a wall in an environment which experiences freeze-thaw cycles is caused when warmer air is trapped in an unvented cavity and is cooled so that moisture is formed. Warmer air has higher relative humidity levels and more moisture than cooler air, and as it cools the problem occurs. This is often a problem on rainscreen systems when EPDM is used to seal up a façade before the cavity.  It was a principle carried out in Canada which has caused major problems.  The extent of material breakdown depends on the type of material used. Past projects suggest that precast concrete has no problems, however dry lining showed signs of mould after a relatively short time. Any seals and gaskets at the interfaces of the façade should be robust because they could suffer damage in freeze-thaw cycles and allow moisture to ingress the building fabric from the inside. 

The cladding system at the American South Pole base does not have a ventilated cavity or use membranes in the same way as cladding systems do in temperate climates.  Finished panels are applied directly to timber sips, but the outside temperature never rises above freezing.  The only natural heating affect might be from solar gain. The moisture risk here is mitigated because the South Pole cladding system  is a front sealed, air tight system which stops air-driven ice and snow at its outer surface.  The temperature on the inside of the building would be 20ºC and so the heat should flow would from the inside to outside. As the outside air temperature is always below 0ºC the relative humidity is either very low or zero, hence no condensation.  As the aluminium covering the SIP are impervious the only area moisture that can be a problem is the interfaces, or at cold bridging points, although these were carefully designed out. 

Similarly, Halley VI for the British Antarctic Survey was built with closed panels encapsulating their insulation core.  They intend to eliminate moisture ingress from both inside and out, that could degrade the insulation under freeze-thraw action. The solution resolves a lot of the problems of the natural environment which includes resisting the accumulation of wind driven particles of microscopic ice, known as spin-drift.  GRP was used as the outer skins to the panels.  It is a workable material to shape and make bespoke complex panels and eliminate cold-bridging.  Closed cell insulation was also used for the core to resist any accumulation of moisture.  The fixing details were carefully detailed to prevent cold bridging and create a robust structural skin. 

Could the cladding principles of the Halley system and its ability to lock out moisture be replicated in cladding systems in temperate environments, either with GRP panels or with a timber SIP system, and eliminate the ventilation cavity?  Yes, however you relying on workmanship and you do not have a second line of defence.  The application of the single ply membrane is depending on workmanship, weather conditions, application methods, location and material used.  The vented cavity system acts to equalise pressure.  When there is a difference in pressure on a façade, some areas will suck in air and other area allow air to be exhausted, which happens in the cavity.  This system reduces the pressure on the façade system.  Due to the temperature difference between the inside and outside of the building, there always will be a pressure difference. 

Different environmental conditions pose different design problems to be resolved with cladding systems.  Even across a single country (albeit a continent) varying and localised environmental conditions might require specific and bespoke design responses.  Importing a fabricated system used in a different country for a project in the UK might not necessarily be suitable if it performs differently because of differences in local climatic conditions.  The conclusion is that we need to thoroughly and carefully study how cladding systems work for each project.  It is not enough to work on a basic understanding of system types, and where relevant, involve a Cladding specialist to help ensure the designed proposals are robust.

Thanks to Will MacDonald, Head of Facades and AECOM for their input in to this post.