Building information modeling based building design optimization for sustainability

Environmental problems, especially climate change, have become a serious global issue waiting for people to solve. In the construction industry, the concept of sustainable building is developing to reduce greenhouse gas emissions. In this study, a building information modeling (BIM) based building design optimization method is proposed to facilitate designers to optimize their designs and improve buildings’ sustainability. A revised particle swarm optimization (PSO) algorithm is applied to search for the trade-off between life cycle costs (LCC) and life cycle carbon emissions (LCCE) of building designs. In order tovalidate the effectiveness and efficiency of this method, a case study of an office building is conducted in Hong Kong. The result of the case study shows that this method can enlarge the searching space for optimal design solutions and shorten the processing time for optimal design results, which is really helpful for designers to deliver an economic and environmental friendly design scheme.

Climate Adaptation: The future of extra-care housing for the elderly in the United Kingdom.

This paper describes the result of a project to develop climate adaptation design strategies funded by the UK’s Technology Strategy Board. The aim of the project was to look at the effects of climate change in the distant future (2080) on a vulnerable group such as older people with special needs and see how architectural design strategies and technologies may be used today to help mitigate problems ahead caused by climate change.
Older people are the most vulnerable sector of society and are particularly at risk in extreme weather, either excess cold in winter or continual high temperatures in summer. In the UK it is predicted that average temperatures may rise by as much as 8 degrees in Summer by 2080 and there will be a 20% greater chance of extreme weather events. This will place extreme stress on the building stock which is designed for today’s mild maritime climate.
The project took a current proposal for an extra-care home for the elderly designed to 2010 regulations and developed a road map to 2080 using climate models developed by the UK Meteorological Office. This allowed the current design to be assessed using future climatic data, proposals for improvement of the scheme to be made within existing constraints and also a new scheme to be developed from first principals using this data, and projections of new technologies that will be available. By comparing these schemes, the approach allowed a reassessment of the initial scheme, and allowed a new design to be developed that offered a more flexible solution incorporating future retrofit which allows new renewable technologies for heating, cooling and water storage to be added at a later date.

The Lake House Extension

The project comprises of the re-ordering and extension of a 19th century country house in the extreme south west of Ireland. The original house is what can be termed an Irish house of the middle size. A common typology in 19th century Ireland the classical house of the middle size is characterised by a highly ordered plan containing a variety of rooms within a square or rectangular form. A strategy of elaborating the threshold between the reception rooms of the house and the garden was adopted by wrapping the house in a notional forest of columns creating deep verandas to the south and west
of the main living spaces. The grid of structural columns derived its proportions directly from the house. The columns became analogous with the mature oak and pine trees in the garden beyond while the floor and ceiling were considered as landscapes in their own right, with the black floor forming hearth stone, kitchen island and basement cellar and the concrete roof inflected to hold roof lights, a chimney and a landscape of pleasure on the roof above.

Aims / Objectives / Questions
1To restore and extend a “house of the middle size”, a historic Irish typology, in a sympathetic manner.
2To address the new build accommodation in a sustainable manner through strategies associated with orientation, micro climates, materiality and engineering both mechanical and structural.
3To explore and develop an understanding for two spatial orders, the enfilade room and non directional space of the grid.
4The creation of deep threshold space.
5Marbling as a finish in fair faced concrete
6Concrete as a sustainable building material

Experimental investigation of thermal inertia properties in hemp-lime concrete walls

Hemp-lime concrete is a sustainable alternative to standard building wall materials, with low associated embodied energy. It exhibits good hygric, acoustic and thermal properties, making it an exciting, sustainable building envelope material. When cast in temporary shuttering around a timber frame, it exhibits lower thermal conductivity than concrete, and consequently achieves low U-values in a primarily mono-material wall construction. Although cast relatively thick hemp-lime walls do not generally achieve the low U-values stipulated in building regulations. However assessment of its thermal performance through evaluation of its resistance to thermal transfer alone, underestimates its true thermal quality. The thermal inertia, or reluctance of the wall to change its temperature when exposed to changing environmental temperatures, also has a significant impact on the thermal quality of the wall, the thermal comfort of the interior space and energy consumption due to space heating. With a focus on energy reduction in buildings, regulations emphasise thermal resistance to heat transfer with only less focus on thermal inertia or storage benefits due to thermal mass. This paper investigates dynamic thermal responsiveness in hemp-lime concrete walls. It reports the influence of thermal conductivity, density and specific heat through analysis of steady state and transient heat transfer, in the walls. A novel hot-box design which isolates the conductive heat flow is used, and compared with tests in standard hot-boxes. Thermal diffusivity and effusivity are evaluated, using experimentally measured conductivity, based on analytical relationships. Experimental results evident that hemp-lime exhibits high thermal inertia. They show the thermal inertia characteristics compensate for any limitations in the thermal resistance of the construction material. When viewed together the thermal resistance and mass characteristics of hemp-lime are appropriate to maintain comfortable thermal indoor conditions and low energy operation.

Development of sustainable, innovative and energy-efficient concrete, based on the integration of all-waste materials: SUS-CON panels for building applications

The building sector requires the worldwide production of 4 billion tonnes of cement annually, consuming more than 40% of global energy and accounting for about 8% of the total CO2 emissions. The SUS-CON project aimed at integrating waste materials in the production cycle of concrete, for both ready-mixed and pre-cast applications, resulting in an innovative light-weight, ecocompatible and cost-effective construction material, made by all-waste materials and characterized by enhanced thermal insulation performance and low embodied energy and CO2. Alkali activated “cementless” binders, which have recently emerged as eco-friendly construction materials, were used in conjunction with lightweight recycled aggregates to produce sustainable concrete for a range of applications. This paper presents some results from the development of a concrete made with a geopolymeric binder (alkali activated fly ash) and aggregate from recycled mixed plastic. Mix optimisation was achieved through an extensive investigation on production parameters for binder and aggregate. The mix recipe was developed for achieving the required fresh and hardened properties. The optimised mix gave compressive strength of about 7 MPa, flexural strength of about 1.3 MPa and a thermal conductivity of 0.34 W/mK. Fresh and hardened properties were deemed suitable for the industrial production of precast products. Precast panels were designed and produced for the construction of demonstration buildings. Mock-ups of about 2.5 x 2.5 x 2.5 m were built at a demo park in Spain both with SUS-CON and Portland cement concrete, monitoring internal and external temperatures. Field results indicate that the SUS-CON mock-ups have better insulation. During the warmest period of the day, the measured temperature in the SUS-CON mock-ups was lower.