Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.

Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.

The concept of adaptability in architecture is one that very often bears technical rather than social connotations. What are the mechanisms and systems that allow buildings to adapt to fluctuating environmental and climatic conditions? These responses are often the driving force behind design considerations, placing emphasis on the manner in which the technical resolutions facilitate appropriate adaptability and environmental response. This adaptability is generally addressed through the building envelope, which acts as the mediator between the interior conditions of a building, and the exterior conditions of its environment (Lovell, 2010). However, beyond addressing these environmental conditions, there are greater urban and social conditions that bear equal weight within any design inquiry. Building adjacencies, ethnographics, social development and imageability of spatial ordering are all fundamental factors that need to be addressed within building envelope design (Lovell, 2010). The design dissertation inquiry explores the multi-faceted nature of building envelopes as well as an architecture of internal and external thresholds. The inquiry examines ways in which building envelopes respond to both the environmental and social complexities of a context, as well as how internal and external threshold and edge conditions can be design generative and communicative; expressing spatial organisations, conditions of privacy and mechanisms of adaptability. This topic of adaptive envelopes and defining thresholds in relation to social complexities has been explored in an architectural design project, which aims to practically address social and environmental issues. This exploration yields a set of key findings into an architecture of thresholds and adaptability in response to the sociotechnical conditions of a context where the lines between the formal and informal are blurred.

The aim of this study was to investigate the effects of windows and building envelope materials on the thermal performance of residential buildings, for the climatic conditions of Ankara. The effects of the thermal mass of the building envelope, together with the effects of glazing type and shading conditions of south-facing windows on thermal performance were investigated using two computer-based thermal analysis programs called: ECOTECT 5.0 and ENERGY-10. The hypothetical building model used for computer simulations was based on the sample residential building defined in the Turkish Standards on the Regulations for Building Insulation, TSE 825, as prepared by the T&uuml / rk Standartlari Enstit&uuml / s&uuml / (TSE, Turkish Standards Institute). Simulation studies were first conducted with ECOTECT 5.0, but since the results did not conform to earlier researches and, since this discrepancy could not be explained even by the support forum prepared by the authors of this software, it was decided to continue the simulations with ENERGY-10, which proved to be more consistent. The results of 240 program runs of ENERGY- 10 were explained through graphical and statistical analysis on the basis of annual heating, cooling, and total energy needs of the building model. The study showed that building envelope materials having high thermal storage capacities together with high-performance glazing, in terms of increased thermal resistance, provided significant energy savings, which could be augmented by increasing the size of south-facing windows. The study also revealed that shading devices in the form of fixed overhangs applied to a south-facing window of any size did not provide substantial reductions in the energy demands of residential buildings, when annual total energy demands were considered for the climatic conditions of Ankara.

abstract: Natural resource depletion and environmental degradation are the stark realities of the times we live in. As awareness about these issues increases globally, industries and businesses are becoming interested in understanding and minimizing the ecological footprints of their activities. Evaluating the environmental impacts of products and processes has become a key issue, and the first step towards addressing and eventually curbing climate change. Additionally, companies are finding it beneficial and are interested in going beyond compliance using pollution prevention strategies and environmental management systems to improve their environmental performance. Life-cycle Assessment (LCA) is an evaluative method to assess the environmental impacts associated with a products' life-cycle from cradle-to-grave (i.e. from raw material extraction through to material processing, manufacturing, distribution, use, repair and maintenance, and finally, disposal or recycling). This study focuses on evaluating building envelopes on the basis of their life-cycle analysis. In order to facilitate this analysis, a small-scale office building, the University Services Building (USB), with a built-up area of 148,101 ft2 situated on ASU campus in Tempe, Arizona was studied. The building's exterior envelope is the highlight of this study. The current exterior envelope is made of tilt-up concrete construction, a type of construction in which the concrete elements are constructed horizontally and tilted up, after they are cured, using cranes and are braced until other structural elements are secured. This building envelope is compared to five other building envelope systems (i.e. concrete block, insulated concrete form, cast-in-place concrete, steel studs and curtain wall constructions) evaluating them on the basis of least environmental impact. The research methodology involved developing energy models, simulating them and generating changes in energy consumption due to the above mentioned envelope types. Energy consumption data, along with various other details, such as building floor area, areas of walls, columns, beams etc. and their material types were imported into Life-Cycle Assessment software called ATHENA impact estimator for buildings. Using this four-stepped LCA methodology, the results showed that the Steel Stud envelope performed the best and less environmental impact compared to other envelope types. This research methodology can be applied to other building typologies. / Dissertation/Thesis / M.S. Architecture 2013

The internal thermal climatic condition of a house is directly affected by how the building envelope (walls, windows and roof) is designed to suit the environment it is exposed to. The way in which the building envelope is constructed has a great affect on the energy required for heating and cooling to maintain human thermal comfort. Understanding how the internal climatic conditions react to the building envelope construction is therefore of great value. This study investigates how the thermal behaviour inside of a simple house reacts to changes made to the building envelope with the objective to predict how these changes will affect human thermal comfort when optimising the design of the house. A three-dimensional numerical model was created using computational fluid dynamic code (Ansys Fluent) to solve the governing equations that describe the thermal properties inside of a simple house. The geometries and thermophysical properties of the model were altered to simulate changes in the building envelope design to determine how these changes affect the internal thermal climate for both summer and winter environmental conditions. Changes that were made to the building envelope geometry and thermophysical properties include: thickness of the exterior walls, size of the window, and the walls and window glazing constant of emissivity. Results showed that there is a substantial difference in indoor temperatures, and heating and cooling patterns, between summer and winter environmental conditions. The thickness of the walls and size of the windows had a minimal effect on internal climate. It was found that the emissivity of the walls and window glazing had a significant effect on the internal climate conditions, where lowering the constant of emissivity allowed for more stable thermal conditions within the human comfort range.

The overall heat transfer coefficient of a building wall, the U value, is an interesting parameter to deduce the heat loss rate through the wall. The current method to determine this U value is well known, but is requires a lot of time to be performed. In this work a new idea of methodology is presented to get an accurate idea of the U value in a really smaller time, using an IR camera. IR thermography is a non destructive method that is mainly used today to carry out qualitative observations. In this work it is used as a quantitative tool to determine the conductivity of a wall knowing the external heat transfer coefficient. The error obtained on homogeneous and heterogeneous walls are smaller than 10 %, which is accurate enough for a fast measurement. The thermal mass of the wall can also be estimated with errors between 5 and 20 %, but only if the user has a good first guess of the real value. Finally some ideas are proposed when the heat transfer coefficient is not known, leading to less reliable results. More work is necessary to transform it as a usable method in everyday life. A part of the report concerns some attempts done with a simulation of the experiment, leading to no concrete results but it is still presented as it took some time to be studied.

Broiler production requires significant expenditures for heating fuel year round. Poor thermal envelope performance leads to reduced live performance, increased energy use, and reduced profitability. Poultry house building component thermal resistance (R-value) is subject to change over time. To characterize the thermal envelope heat transmission and building component R-value of two broiler houses of different ages, conductive heat flux (W/m2) and temperature gradient (Delta T °C) were monitored with heat flux meter (HFM) arrays and temperature sensors over a 13-month period. Net heat loss and building component (walls and ceiling) thermal resistance were determined from the data. Results showed differences in net heat loss were observed for the ceiling zones where 84% more heat was lost through the ceiling of the older house than that of the newer house (P < 0.05). R-values determined from field measurements for both houses were below estimated theoretical composite R-values. Observed R-values were greater for ceiling envelope zones of the newer house when compared to the older house. Increased heat loss and reductions in ceiling envelope zone R-values for the older house were attributed to shifting and settling of the looseill cellulose attic insulation material, which was especially prevalent at the ceiling peak zone. To verify the feasibility of using sol-air temperature in lieu of outside air temperature to account for radiant load during warm conditions, field measurements of temperature (°C) (interior air, exterior air, and exterior surface) and solar radiation (W/m2) were recorded of a broiler house. Sol-air temperatures were calculated from these data. Observed maximum daily air temperatures were significantly different (P<0.0001) from maximum surface and sol-air temperatures. Maximum surface and sol-air temperatures were not significantly different (P=0.2144, P=0.1544). Simulations of conductive heat transfer by air and sol-air temperatures using climatic data showed heat gain as calculated by sol-air Delta T was considerably higher when compared to heat gain calculated by air Delta T. This study supports the rationale that the sol-air temperature concept results in improved estimates of conductive heat transfer during daytime conditions which can be used to optimize insulation and ventilation requirements for broiler houses during warm conditions.

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Sustainability of the built environment is one of the most significant challenges facing the construction industry, and presents significant opportunities to affect change. The absence of quantifiable and holistic sustainability measures for the built environment has hindered their application. As a result, a sustainability performance metric (SPM) framework was conceptually formulated by employing sustainability objectives and function statements a-priori to identify the correlated sustainability indicators that need to be captured equally, with respect to the environment, the economy, and society. Projection to Latent Structures (PLS), a latent variable method, was adopted to mathematically formulate the metric. Detached single-family housing was used to demonstrate the application of SPM. Datasets were generated using Athena Impact Estimator, EnergyPlus, Building Information Modelling (BIM), Socioeconomic Input/Output models, among others. Results revealed that a holistic metric, such as the SPM is necessary to obtain a sustainable design, where qualitative or univariate considerations may result in the contrary. A building envelope coefficient of performance (BECOP) metric based on an idealized system was also developed to measure the energy efficiency of the building envelope. Results revealed the inefficiencies in the current building envelope construction technologies and the missed opportunities for saving energy. Furthermore, a decision-making tool, which was formulated using the PLS utilities, was shown to be effective and necessary for early stages of the design for energy efficiency. / Thesis / Doctor of Science (PhD) / Sustainability of the built environment is a significant challenge facing the industry, and presents opportunities to affect changes. The absence of holistic sustainability measures has hindered their application. As a result, a sustainability performance metric (SPM) framework was formulated by employing sustainability objectives and function statements a-priori to identify the indicators that need to be captured. Projection to Latent Structures was adopted to mathematically formulate the metric. A housing prototype was used to demonstrate the application of the SPM utilizing a bespoke dataset. Results revealed that holistic metric, such as the SPM is necessary for achieving sustainable designs. A building envelope coefficient of performance metric was also developed to measure the energy efficiency of the building envelope. Results revealed the inefficiencies in the current building envelope technologies and identified missed opportunities. Furthermore, a decision-making tool was formulated and shown to be effective and necessary for design for energy efficiency.