Designing A Garden Shed In Barrington: Objectives And Material Requirements

The Learning Objectives

• used appropriate terminology to describe materials and their properties defined materials properties and their design considerations
• used appropriate classification systems to categorise materials used in construction
• acknowledged the environmental implications of materials and their manufacture made informed decisions about materials in specific design situations
• identified a range of commonly used construction materials and describe the rationale for their application
• described the manufacturing processes which provide the predominant construction materials

As a student in university taking construction related course, I was approached by Rosemary to help her propose on an aesthetically pleasing and functional garden shed in his property in Barrington. The size of the design is preliminary planned to be approximately 24 feet by 18 feet. According to the client’s requirement, the garden shed will house a number of spaces, which include a glass house where Rosemary can grow edible plants since the temperature in Barrington is cold and the plants need a warm effect of the green house to grow healthy. Other spaces will include a simple preparation space and cool rooms where the fresh food can be cleaned, cut, and stored since the produce are mainly perishable. A small area should also be cleared to include a patio that can be included as part of the project. The garden shed will be supplied with electricity from the 4-bedroom straw bale home and the structure must be constructed according to the Australian codes and guideline.

• The main goal of this eco-shed design is to strike a balance between cost effectiveness and eco friendliness.
• Design and build the garden shed using ecofriendly building materials that have no or minimal effect to the environment and the building inhabitants.
• Design functional and secure spaces that will require enough storage for tools, produce; and cold frames.
• Hope that the garden shed will provide a future reference for an ideal requirement and design of green building on a smaller scale.

Choosing a perfect site location for our garden shed is a very important factor to be considered. In our case, the shed will be built on a rural block of land in the town of Barrington.

The most important aspect of building design is the trust between the client and the architect. Without trust in a building project, there will be huge losses incurred that might lead to the incompletion of the project. However, in my case, the client is friendly and open on what she really wants. Her illustrations and requirements are very clear. Since Rosemary is a gardener, she wants a modern garden shed that will house her garden tools, glass house, and a cold room. The client has enough budgets for the project and as the designer; it gives me freedom to explore on the quality of finishes and the level of details of the shed design since there is no budget restriction.

For the proposed design to be successful, it is important to carry out a site analysis. This involves taking an inventory of the elements on site and analyzing them relative to the client’s needs. Information gathered on the site properties includes topography, climate, and vegetation. These elements are then analyzed and incorporated into the design.

A graph showing Barrington rainfall and temperature throughout the year

Source: (Green, Stein, & Driessen, 2008)

The type of climate experienced in Barrington is cold and temperate. This means that the place receives reliable rainfall all year round. According to Koppen, this kind of climate is referred to as Dfb, which is humid continental climate (Green, Stein, & Driessen, 2008). The average rainfall and temperature in Barrington is 1123mm and 7.6 degrees Celsius respectively (Green, Stein, & Driessen, 2008). With this type of climate, it will be worth it to use the roof for harvesting the rainwater to be used in the cleaning room for washing the produce. A water butt will be installed to help in this process.

Objectives

A chart showing Barrington wind rose

Source: (Green, Stein, & Driessen, 2008)

Barrington wind rose shows the number of hours wind blows per year from a certain direction. An example is South West. Wind blowing from SW to NE. The southern part of land mainly points to South America, which has strong winds coming from the west, which makes it difficult to sail East to West (Green, Stein, & Driessen, 2008). This information plays a very important role on the orientation of the shed how the shed to optimize on the design.

The type of soil below the foundation always determines the stability of the structure. Most part of Barrington is made up of deep, moderate, and well-drained soil formed in water laid silty material and underneath calcareous loam outwash, that is stratified (Green, Stein, & Driessen, 2008). With this type of soil, it is appropriate to use strip foundation and the depth of the foundation to be determined on site.

Infrastructure facilities 

Other services to be considered on site is the water supply, waste disposal, electricity supply, and drainage connection are very important factors to be considered during planning the zoning.

Locally available resources 
The available material on site include timber and straw bale. This means the cost of transportation will greatly be reduced. The extra straw of bale used in construction the 4 bedroom can be used if there is need to explore their usability in the shed construction.

The garden shed will be made of mainly hardwood timber. There will be square or rectangular prefabricated wood panels that can be joined using bolts. The roof material will be waterproof cedar shingles. Alternatively, the roofing felt can be used. Shingle tiles are also eco-friendly to the environment and can be incorporated into the roof.

To build the frames, we need pallets, nail guns, nails, tape measure, and a circular saw. In most cases, lightweight construction is the most appropriate for garden shed construction (Halliday, 2008). To frame the floor we need to lay two pallets on the ground. The wall will be framed using the wood to get the skeleton of the garden shade. Wall framing will then help to support the frame of the roof truss since the roofing material have to be laid on the roofing frame to achieve the desired outcome. Wood frame will be appropriate for the truss structure and adding wood slate to the frame to be able to support the roofing material.

Site Location

The preferred material for wall construction will be square timber panel because of its environmental benefits. Timber are from a renewable source, sustainably sourced, non-toxic during its use, is low in embodied carbon, thermal bridging, low waste rates, appropriate for life span, flexible and adaptable. The timber panels will be lime rendered in white to help in reflecting any excess heat from the sunrays. From a sustainable point of view, timber is a renewable building material able to absorb carbon from the atmosphere, and this makes it able to sustain the life of the building (Haselbach, 2008). However, timber used should be treated from termites and since the temperature in Barrington is cold, the timber used should be free from moulds and any kind of rot.

It is important to consider the right roofing material for roofing shed considering that Barrington receives heavy rainfall all year round. The first consideration should be a material that is waterproof, environmental friendly, affordable, pleasant, and durable. The best material to be used in roofing the shed is cedar shingles made from pine, cedar, redwood, or the western red cedar (Kibert, 2016). However, it is important to note that roof shingles are not fire resistance and should be treated with flame retardant to prevent any form of fire accident. On the other side, wood shingles are visually appealing, high degree of thermal insulation, have low carbon footprint, and are made from a natural source that is renewable (Kim & Harries, 2010). To install the cedar shingles, we shall first have the roofing felt lying on the rafters to achieve the desired quality finish. The attic space will also be high to give more space for air circulation that can result into the stack effect in the room.

Getting the right floor material for the garden shed is very important, considering that the floor will have to handle water; it is therefore advisable to use a waterproof material. The proposed material for the floor is wood parquet; however, it should be treated to prevent the floor system from root to make it durable. Treating the floor system to being waterproof should start from the floor framing system including the outdoor deck. The best approach is to use the treated lumber floor joist that is raised 6 inches off the ground (Madurwar, Ralegaonkar, & Mandavgane, 2013). This helps to keep away animals such as the mice. The wood parquet can be improved by applying 3 coats of polyurathane clear lacquer vanish to make the material aesthetically pleasing and adding to its property of being waterproof.

Brief Analysis

Doors will definitely require lintels. The best-engineered timber solutions will use laminating, gluing, and jointing techniques to increase the tensile and compressive strength of the grades of the timber on the lower side and overcome natural weaknesses such as warping, bowing, and splitting (Matthews et al., 2014). The materials to be used include plywood, and glass.  It is important to take care of these materials internally in order to ensure that they have no adhesive that can interfere with the indoor air quality. The cool room will have insulated panic doors to maintain the low temperature required while the main doors to the glass house will be made of glass due to its sustainability and helps to control the climate change.

During the construction of the buildings, the bales should be stored in dry areas to prevent the development of mold. Windows tend to be a point of failure due to water invasion, so they should be well detailed.

Due to the cold climate in Barrington during the winter, appropriate measures need to be taken in the design of the garden shed. The shed will be built largely by the use of wood in order to marry with the design of the house and add to the appearance of the yard.

The glass part of the shed should have a north or northeasterly aspect and free from shadow cast from neighboring buildings or trees. The roof will also have a steep pitch of 48⁰ also to ensure maximum transmission of light into the enclosure.

  Cooling of the glasshouse is very important in the summer hence vents should run throughout the whole length of the highest point of the roof and a corresponding area of vents at the bottom to allow the intake of air. To ensure that the light is absorbed fully once penetrated into the glasshouse, the interior and heat storage should be dark in color to improve on thermal mass of the building. The floor will be insulated from surrounding soil and heat lost through the glass by conduction to the outer surfaces and thereafter through convection to the air can be retained by the use of insulating shutters or blinds, which are lowered at night (Pan, Gibb, & Dainty, 2007). Double-glazing the windows can also solve this problem.

Due to the need of a cold room, a blend of construction materials will be required such as polyurethane sandwiched between stainless steel to control temperatures inside.

Material Requirements

Conclusion

The proposed garden shed will be located in a rural block of land in Barrington. The spaces accommodated inside the shed will include a cleaning area, a storage room and a glass extension incorporated into it. The shed would be elevated from the ground to prevent loss of heat to the ground and from rot and pests. The materials used in the construction of the shed are lightweight construction materials comprising of timber, glass, and straw bales. The shed shall be built using a timber frame and straw bales as in fills form the walls to conserve the theme with the main house and strike a balance between cost effectiveness and eco friendliness. The floor shall be made of wood parquet and the roof shall be made of wood shingles. The glass extension shall have special treatments in terms of its design including high-pitched roof for maximum sun penetration, dark interiors for heat absorption and high level and low level vents for ventilation. The glazed enclosure wood use the timber framing to continue the wooden theme in the shed

The cold room shall also receive special treatment in terms of its design where the walls shall be composite walls made of polyurethane and stainless steel to preserve cool temperatures. A small area should also be cleared to include a patio that can be included as part of the project to improve the entrance in terms of aesthetics.

The shed will be located far from the main house and far from the sources of firewood to prevent spread of fires.

The straw bales should be preserved in a dry place during construction to prevent the growth of moulds. The walls should also be water tight to ensure no water sips into the straw.

The wooden members used in construction should be appropriately treated to prevent attack from rodents and other pests

The windows and doors should have a special detailing as they are considered weak points and therefore more susceptible to leaks into the walls

The orientation of the building should be such that the glass enclosure faces the north or northeast direction for maximum sun transmission. The glass windows should have blinds installed on them to prevent heat loss through conduction and thereafter through convection in the air or the glass panels should be double-glazed.

The floor of the glazed area should be well insulated to prevent heat loss during the winter and increase the thermal mass of the floor.

The roof should have a gutter system to ensure that the rainwater is harvested and used when it is needed. The threat of bushfire is a real concern in Australia and the shed should be sufficiently weather proofed and protected.

The use of a waterproof paint with a flat, satin, or eggshell finish should blend into its natural surroundings. The shed should be slightly detached from the ground –create a substructure and ensure the shed cannot be damaged from below

The windows and doors should have screens to prevent entry of pests and help in keeping it fireproof. A solar chimney or exhaust fans may be needed as supplementary shading from a shade cloth or whitewash.

References

Coulson, T. (2012). Integral projections models, their construction and use in posing hypotheses in ecology. Oikos, 121(9), 1337-1350.

Green, K., Stein, J. A., & Driessen, M. M. (2008). projected distributions of Mastacomys fuscus and Rattus lutreolus in south-eastern Australia under a scenario of climate change: potential for increased competition. Wildlife Research.

Halliday, S. (2008). Sustainable construction. Routledge.

Haselbach, L. (2008). The engineering guide to LEED-new construction: sustainable construction for engineers. McGraw-Hill.

Kibert, C. J. (2016). Sustainable construction: green building design and delivery. John Wiley & Sons.

Kim, Y. J., & Harries, K. A. (2010). Modeling of timber beams strengthened with various CFRP composites. Engineering Structures, 32(10), 3225-3234.

Madurwar, M. V., Ralegaonkar, R. V., & Mandavgane, S. A. (2013). Application of agro-waste for sustainable construction materials: A review. Construction and Building Materials, 38, 872-878.

Matthews, B., De Meester, L., Jones, C. G., Ibelings, B. W., Bouma, T. J., Nuutinen, V., ... & Odling-Smee, J. (2014). Under niche construction: an operational bridge between ecology, evolution, and ecosystem science. Ecological Monographs, 84(2), 245-263.