Cem 154 – Design and Evaluation
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Cat Graduate School of the Environment
Design and Evaluation
Student name Iver Salvesen
Student Number U0958360
Seminar Group A Jason Hawkes and Gerry Jones Ceinws Forest Village
Module date June submission date 12th September
Given account of the design process adopted by your group and comment on its merits and defects
Our design group chose to follow a traditional approach to designing the community space and homes , at Ceinws Camp. In doing this we chose to follow the design stages adopted by the RIBA.( Clifton 2011) i.e Work Stage A : Inception, Stage B: feasibility , Work Stage C: Outline Proposals, Work Stage D: Scheme Design and Work Stage E: Detail design. We knew that out brief could not at this stage also encompass much of the further design stages, i.e the preparation of bills of quantities, product information tender documentation and project planning through to on site activities as the scope of the brief and time constraints of the weeks design module prevented much work in this area. Thus in my evaluation of the design module I will not include much in the way of reference to these later stages. This process of design has been working well as a model for client work for Architects for many years. We consulted a member of the community, master-planned the site, re-consulted and re-considered the brief after outline proposals however recent changes are being adopted by Planners after the publication in 2007 of CABE “Its our space” and more recent legislation, (Communities 2011) has brought greater emphasis on much deeper local community consultation . These more recent documents were not considered in our design process.
Our site is located in a wooded area of Wales on the edge of the Dyfi Forest,( Forestry Commission 2010) part of the site is overshadowed by hills covered in maturing conifers and much of the site is crossed by low pylons. While the site is on the edge of a region beginning to be populated by some major new wind farms ( CUP 2011) the local wind resource is not great. The solar resource is in the region of 1150kwh/m2 (Photoenergy 2011) so this resource was seriously considered. We also looked at the local water resource, there is a stream through the site and a river at the site base, where potential for a closed loop heat pump was discussed and a hydro scheme briefly considered. However in our design process we believed that to design out power need as far as possible by the adoption of passive house standards (Kolle 2010) for the construction of new units and thus reducing the power need we would achieve the optimum solution. In a world context we are in a period of climate change due to CO2 emissions caused by human energy use (Guggenheim 2006) and must seek to reduce human impact as far as possible.
We chose to provide the energy need for the site from a centralised Biomass Boiler system. This has the advantage of actually, on our initial calculations, actually making money for the site under the Renewable Heat Incentive ( DECC 2011) after an 8-10 year payback on initial investment. The wood resource is local, it could not be much closer in fact with the forest edge starting across the road from our site. In terms of overall efficiency compared to Fossil Fuels ( Dr Kenneth Means 2010 ) the cost per million BTU of waste timber is less than that of Coal Gas Oil and Electricity , though using pelletized wood is not ( Rapier 2010) So the choice of system for creating the heat is important. We can obtain the timber locally under a Firewood Framework Contract from the Forestry Commission, so the fuel is not only nearly, but accessible. The maintenance and running of the system may create a part time job within the community on an ongoing basis maintaining and running the plant. Using local skills of the technicians at the nearby CAT facility has some distinct advantages as this may be able to be done to the economic benefit of both parties. We decided that a CHP plant would not provide sufficient Electricity for the site as the power output is generally 2:1 (FC 2011) and the electrical need of an occupied domestic sized dwelling is higher proportionally than its heat requirement (González et all 2011) Thus for electrical need we assumed that we would be grid connected and that the Biomass plan would only produce Heat. We looked at electricity production from a Wind Turbine and believe that a community wind turbine for the whole community would be a viable option. There are already local wind turbines to the Ceinws site producing surplus power to the grid. If I compare the site to the experience at the Findhorn community of a centralized power grid.(Findhorn 2011) I believe that we could find a local location off the site up a hill where the community could using the power on a private grid produce 100% of the electrical needs of the community and still export some power to help defray costs of the initial infrastructure installation. This is possible in the current Framework of Feed In Tariffs available under contract with government and local power companies (DECC 2010) The third power source we looked at was the local river. We looked at both electricity and heat from an open loop heat pump through the river Dovey. While there is great merit in using water to supply a heat pump and more for the supply of continuous electricity as the source is so local (US Department of the Interior 2005) “The key to the usefulness of such units is their ability to generate power near where it is needed,”Page 11 There are significant environmental issues with hydro installations, less so in rivers than for large Dams (Baird 2010), ownership water head and red tape may prove to be stumbling blocks.
Our group chose passive house standard as it offers flexibility in terms of design suited to the linear nature of the homes we chose to create around a central space. This allowed us to orient the main run of homes to the south and west where they could capture what there is of the solar resource passively. The increased costs of insulating the homes and the detailing for air-tightness far outweigh the heat losses that would otherwise occur ( Sartori 2007) over the lifetime of the building creating a benefit and reducing the energy required to run the home by a factor of four. We were limited in terms of orientation and design layout in capturing all the passive solar gain we could in the initial design phase but I feel by careful placement of the homes in a review phase we could have further increased the energy performance of the homes while keeping the same feel of the site.