James Rennie, university of Nottingham, architecture K100, 2011, unit 1A,
This blog site aims to document my experience at Eco-build 2011. I was there from Monday to Wednesday morning . I then explored and researched some of the ideas presented further. It is important, I feel to have an awareness of new technologies, assess their impact and their uses. I wanted to ask how I could apply some of the technologies seen to studio design projects. I also wanted to assess there aesthetics, sustainability factor, their use in design and to criticallycomment on how it impacted my structural knowledge and my outlook on eco design and structure.
The audios where recorded on my Olympus DM450 recorder and uploaded them to dropbox and , I ask questions and recorded the replies, I have annotated the audio, and expanded on the information explained in the audio. The recorder was an extremely useful note taking tool. enabling me to record my interaction at Eco build. The clips are between 2 minutes and 30 minutes but I have highlighted important aspects of the clip, if you have the time I encouraged you to listen to the whole of the clip as you get a feel for the process and the way I experienced the show.
I wanted to produce a blog as it allows me to share useful links, information and audios. It is an excellent research tool good allowing me to go back update and add to information as required.
Blog contents
1.lighting v.s nature
2.Straw bale construction
3.How PVs work
4.Green roof construction
5.Rammed earth, the process
6. Glulam beams
Saturday, 14 May 2011
Lighting v.s. Nature- Not too relevant to my subject matter, but important to appreciate in future design.
-should wildlife take preference over human visual needs- impact and value
-relative impact on animals and relative needs of humans. High value on humans, and high impact on animals.
-Humans must address safety and security. Lighting reduces crime rate. Lighting has been shown to be more cost effective than cctv
-This is the 2D diagram he mentioned in the video
I asked a question at the end, on lighting in architecture, my question wasn't returned with a fulfilling answer however the whole topic is an interesting one to consider in the design process. One which hasn't been covered in my architectural education so far.
audio demonstration by www.amazonails.uk.org. the information bellow was also found on there website.
Nebraska (also called Loadbearing) this is the method described in the demonstration I watched at Ecobuild
Advantages:
•A simple, straightforward and accessible building method
•Easy for non-professionals to design, following readily comprehensible basic principles.
•Designs from one room to two-storey homes can be created using a simple, step by step approach.
•Curves and circles are easy to achieve, for little extra cost.
•Ideal for self-builders because of its simplicity, accessibility, ease of design, and low cost.
•The straw is very forgiving. Total accuracy in plumb is not a design goal but wilder variations can be brought back into shape easily!
•Great versatility of design shape.
•It's fast!
Disadvantages:
•The straw must be kept dry throughout the whole building process until it is plastered, which can be very difficult on a large building, or one that is being constructed slowly.
Openings for windows and doors should not exceed 50% of the wall surface area in any wall (but hybrid methods can be used in these cases).
The following table shows how the insulation values of an amazonails standard build* complies with the new Building Regulations (the lower the value better the insulation):
Specifications determining houses without any need for heating or cooling take the requirements for the building insulation much further:
•The Association of Environment Conscious Builders (AECB) silver standard specifies measures leading to overall 70% reduction of CO2 emissions compared to the UK average for buildings of each type.
•The AECB golden standard aims at reducing overall CO2 emissions by 95% and is almost identical with passive house standard, that describes the buildings insulated to such a level that they could be heated by mere presence of people without any internal source of heat.
•BRE Zero Heating House Standard defines a similar goal.
Following table shows how the insulating values of different specifications comply with insulating values of amazonails standard build.
The sustainability and use of renewable materials
Reducing carbon emissions
High insulation and low heating bills
Good sound insulation
Low fire risk
Low cost
Healthy living environment
Creative and fun places to live
I think this was one of the most honest stands at ecobuild, I think like rammed earth it is very labour intensive, but the human interaction with the building process is visable in the final product
I do not know very much about photovoltaics so my visit to Ecobuild was my chance to learn about them as they are currently one of the most accessible ways of generating renewable energy
PV (arraysturning radiation into electrical energy)
Most common are silicon cells, they work when exposed to the sun (direct current DC flows). PVs respond to both direct sunlight and diffused radiation. Cells are combined to form modules these cells which are of a very low voltage are joined in series to form modules of a higher and more useful voltage, a line of modules are called strings and groups are called arrays. Power from the array goes to the power-conditioning unit. A PCU is a general term for a device that converts the electrical energy into a suitable form for the building. An inverterchanges the DC current into AC which then goes to a distribution board in the building to supplement the electrical demand or be connected into the electrical grid.
The output of the array depends on
-Seasonal conditions
-Location in terms of sunlight
-Tilt
-Shadowing
-Temperature
The use of PVs should be part of the overall energy strategy for the building and should be considered particularly important if certain key factors are in place:
-Location – the radiation at the site is important (access).
-Usage – the building should have the electrical requirement.
More expensive than buying from national grid – factories and offices have a high daytime use so can utilise the benefits more effectively, houses however are used day and night and are forced to depend on the national grid
When exposed to sunlight the modules heat up, this is normally removed by ventilation, but the heat can be used to help supplement the buildings total heat requirement.
Array positioning
-Roof based systems
-Façade systems
- Purpose built
- Sizing depends on the site available
- Required energy consumption
- Contribution to overall electrical load
- Availability of area
- Budget
The modules will normally be connected in such a way as to produce a more usable higher voltage from the array with the exact voltage being dependent on the system
Monday, 9 May 2011
Green roof and brown roof construction
There where many contractors selling there ideas on green roofs, I spoke to a representative from http://www.blackdown.co.uk/. I found out some of the possibilities of green roofs and researched the topic further
Assuming you have a supporting structure- does it take the weight of the foliage and the water (irrigation) as soon, any green roof beyond sedum(http://en.wikipedia.org/wiki/Sedum)needs a strong structural strategy.
Sedum supports one species. The brow roofs support more)
In planting a Special foliage can be used to attract a certain types of wildlife.
further research;
Green roofs deliver benefits to urban areas in particular. They insulate and they protect roofing materials; they clean the air and help fight climate change; they create rich micro climates. In urban areas they create necessary green spaces for work and leisure. Scandinavia has had green roofs for centuries, it has now become trendy and attractive to promote biodivercity, particularly in the UK.
Green roofs can be divided into 3 catorgerys
a.Intensive - a 1000mm plus layer of soil in which a variety of plants and trees are grown. As I discovered in the conversation I had with a representative representative of http://www.blackdown.co.uk/ these roofs are the best option to encourage biodivercity they need to be maintained regularly. The loads produced are significant, so an effctive structural strategy needs to be considered.
b.Extensive - 25 - 100mm shallow layer, often referred to as sedum because of the low growing moss or alpine species such used in the planting. The lightweight systems requires little to no maintenance
c.Semi-extensive – 100 - 200 mm- inbetween intensive and extensive, there focus however is on allowing little maintenance and reducing structure constraints an intensive room would put on the building, but maximumizing biodiversity.
Green roofs can effectively be created on any surface. any pitch that exceeds 9.5° will however have specific water retention requirements.
Construction requires a series of layers which have different functions; to retain the necessary water that will sufficently support the plants, but to also allow drainage, the roof needs to be pretected from roots and plant growth.
4.Drainage layer (such as Isola Platon DE 25 membrane, supplied by Triton. This membrane has a special 23mm deep stud design which combines drainage and water storage to maintain long term roof planting.)
5.Root barrier
6.Waterproof membrane
Other ways of promoting biodiversity in a building;
Green infrastructure, such as habitat walls provide multiple benefits for both people and wildlife. Habitat walls are one of the most important wildlife resources. They can be characterized as a hotel where insects can shelter and lay their eggs. They can also be feeding places for insects, amphibians, reptiles and small mammals, and provide them with nesting materials. Through the habitat walls the relationship between people and natural world is enriched. A healthy natural environment provides the foundations for future growth and prosperity and provides the setting for healthy and happy communities.
Green roofs are significant to my studio sites, and believe they should be seriously considered. Carsington Waters is extremely biodiverse, this biodivercity atracts visitors. a green roof could be a way of encoraging this biodivercity www.carsingtonwater.com
I had the pleasure of helping set up the rammed earth building stand (s1260) The hands-on experience helped enormously in understanding the processes and stages involved
The stages
1. Erection of formwork
2. mixing
4. filling
5. ramming
6. removal of formwork
Mixing
the video shows what we did but on a larger scale- we used shovels and a watering can instead of a digger and hose, it has the same effect and achieves roughly 10% water mix by weight. this is considered best practice. A rule of thumb test can be done by dropping a 1cm size chunk of mixed earth from head height, if it breaks into 4 or less clean pieces it is ready to be filled and rammed
Corners in the formwork are often achieved with different tools- there are delicate indentations, a thinner rammer that is shaped appropriately would be used for corners
The art of an even and uniform result is achieved by following the sequence fill-ram, fill-ram etc., circulating the wall using this sequence to attain a moderate and even density. By bringing the walls up evenly there is less pressure on the formwork and the walls can be moderated and start to support themselves.
Measuring tool. The measuring stick rests at the base of the wall or on an area that has been rammed. A filler would fill to the appropriate depth, the depth that is used continuniosly throught the project at each point on the wall. 60cm for example.
We where taught that when filling we should push the earth against the edges of the formwork, this stops the stones from forming the visable face of the wall. (achieving the opposite of what happened in picture 8)
The importance of force- by pushing the rammer down you ram everything that’s just been filled, so not just the top layer is effected, this application of strength and thoroughness is very important, the effectivness of this is denoted by the change in tone the rammer makes when it hits the compacted earth, this is demonstrated at 12.00 of the audio above
This process of fill ram, fill ram continues up methodically until the wall or building is completed, the formwork is then moved (on the wall we were constructing we filled on one side then rammed then filled and rammed the other side then returned to the previous side to fill and ram and so on (see picture 2) the result Is a solid load bearing wall.
Adding colour audio DM450010 We were briefly shown methods on adding colour and embossing logos onto the walls. interesting questions are asked in this video about shape, formwork and how different finishes or paints would react to the wall
There are many advantages to rammed earth construction however labour intensive it is. I spoke to Rory the person leading the workshop about client issues with this method. he said one of the biggest issues he finds is that they don't realise how the colour changes and "dulls". After 6 months when the building has fully dried and combined they expect what was erected in the first place to be the final place.
-Gluelam is composed of several layers of timber, stuck together with water proof adhesive, the composition of several small layers means curved forms can be articulated and reproduced may times. As a result they are very lightweight
Its more sustainable and effective when compared to solid sawn timber. Solid sawn timber has a large amount of waste in its attempt to get the best sectional cut. Glulam takes advantage of smaller sections stuck and arranged in the beams advantage.To get the same effect as Glulam solid sawn timber needs much larger trees that have a longer growth time. the overall effect of harvesting trees is much smaller for glulam as the process is faster.
Glulam is 2/3 the weight of steel and 1/6 the weight of concrete. This makes transportation costs less
The only limitation is perhaps access to the site and size of the beams. However they are usually used only to articulate certain elements.
I spoke to Pasquill (www.pasquill.co.uk). They provide glulam timber solutions for projects which do not want to use steal or concrete. I recorded a conversation with a representative for the company at their stand Ateco build, in the audio I asked how the product compares to both concrete and steal and if transport is factored into its embodied energy. I apologise, at some point the back ground noise blurs the conversation. but the audio elborates on the pros of the product.
In reply to a question about sourcing timber from the UK they replied that the timber from Scandinavia is stronger and they can get higher yields.Rather than depleting the UK' wood supplies, they can rely on forestry rotation in Scandinavia. Although this effects transportation costs this would be far more if you where transporting steel or concrete.
Benefits of Glulam –(from the company’s brochure)
-suitable for large spans
-high strength to weight ration
-malleable
-the appearance of timber over concrete and steal – in reference to my studio project I would prefer timber, concrete and steal would contradict the organic elements in the site
-good fire resistance
-good chemical resistance
-can be worked using ordinary tools
-surfaces can be treated
-sourced from well managed forests, chain of custody certified
-recyclable
-generates less co2 than many other building products
-thermally efficient compared to many other building material
-dimensionally stable
the company has a good green stratergy
the technical info illustrates there parameters, but in general they are suitable for many facilities and uses
I’m considering using gluelam beams in my current studio project, they span maximum 22m, im constructing a relatively small building- similar to a market space, the beams would hold a tent fabric that would be adjusted seasonally. The rest of the structure world be cladded by recycled or reclaimed timber.
