The performance of award winning houses (original) (raw)

Perceived and prescribed environmental performance of award winning houses

This paper investigates the thermal performance of three RAIA award-winning houses. It compares the occupants' assessment of the thermal environment with thermal comfort defined in ANSI/ASHRAE Standard 55-1992. Actual household energy use is compared with AGO figures for standard houses in that location and the house compliance with the recently introduced energy efficiency provisions of the Building Code of Australia is also assessed. The study found that all three houses do not conform to the above Standard and Code. It was predicted that unacceptable amounts of heating and cooling energy would be required to achieve thermal comfort. Despite this, the actual energy consumption of these houses was lower than standard houses in the same regions. The occupants were largely satisfied with the houses' thermal performance and indicated they had no plans to modify the building or install air-conditioning or other systems to achieve the prescribed thermal comfort. This paper pos...

The impact of thermal comfort criterial on energy consumption of residential buildings

2017

In Australia, the current Nationwide House Energy Rating Scheme adopts a variation of the ASHRAE 55‐2013 adaptive thermal comfort method with a criterion of 90% acceptability. It has been debated that such a high acceptability requirement may be too strict for residential buildings, and a criterion of 80% or even 70% acceptability may be adequate. This study evaluates the impact of thermal comfort criteria on space cooling energy requirement in three typical climates (Melbourne‐heating dominated, Sydney‐balanced heating and cooling, Darwin‐cooling dominated) in Australia through building simulation. The results show that under both current and future climates (assuming a global warming temperature of 2°C), the decrease from 90% to 70% in the acceptability has minor or no impact on housing cooling energy consumption in Melbourne and Sydney. However, it may have significant impact on space cooling energy consumption in Darwin (saving more than 40%). It was found that for high‐set ligh...

Assessing Australia’s Residential Building Energy Efficiency Regulations

2018

Australia has had minimum energy efficiency regulations for new residential buildings for over a decade. Assessment is undertaken using thermal modelling software that determines the thermal efficiency of the building envelope and awards a star rating out of ten. Despite being in place for many years it is only recently that data has been captured and analysed. This has allowed the ability to assess the effectiveness of the regulations and determine strengths and weaknesses in the assessment process. This paper discusses the initial insights that have been achieved through analysis of the data. Almost 200,000 assessments are in the HStar database, providing insight into how well dwellings are achieving the requirements based on location, dwelling type and dwelling size. Data on construction systems utilised allows analysis of approaches that designers and architects have used to achieve the requirements. This includes building material choices for walls, floors and roofs and insulat...

Does size matter: a comparison of methods to appraise thermal efficiency of a small house

The Energy Efficiency provisions, within the Building Code of Australia, have created many new challenges for architects and building designers. Prior to these provisions, general environmental design principles and 'rules of thumb' were used to design environmentally conscious dwellings. As the greenhouse agenda has advanced, the architect and building designer are now faced with understanding the effects of their original environmental design training, set parameters in the deemed to satisfy provisions of the BCA and house energy rating simulations. In some situations the logic of the rule of thumb approach seems to be questioned or contradictory to the resultant star rating. This paper will illustrate a recent design experience of a small residence in Launceston, Tasmania. The new dwelling was designed by using 'rules of thumb' for passive solar and environmental design and the philosophy of making a well insulated small box. The design was submitted to a Home Ene...

Impact of standard construction specification on thermal comfort in UK dwellings

The quest for enhanced thermal comfort for dwellings encompasses the holistic utilization of improved building fabric, impact of weather variation and amongst passive cooling design consideration the provision of appropriate ventilation and shading strategy. Whilst thermal comfort is prime to dwellings considerations, limited research has been done in this area with the attention focused mostly on non-dwellings. This paper examines the current and future thermal comfort implications of four different standard construction specifications which show a progressive increase in thermal mass and airtightness and is underpinned by the newly developed CIBSE adaptive thermal comfort method for assessing the risk of overheating in naturally ventilated dwellings. Interactive investigation on the impact of building fabric variation, natural ventilation scenarios, external shading and varying occupants’ characteristics to analyse dwellings thermal comfort based on non-heating season of current and future weather patterns of London and Birmingham is conducted. The overheating analysis focus on the whole building and individual zones. The findings from the thermal analysis simulation are illustrated graphically coupled with statistical analysis of data collected from the simulation. The results indicate that, judicious integrated approach of improved design options could substantially reduce the operating temperatures in dwellings and enhance thermal comfort.

Unintended consequences of sustainable architecture: Evaluating overheating risks in new dwellings

2016

Governmental strategies to reduce heating demand from dwellings have led to a range of problems relating to ventilation and occupant comfort. In fact, growing evidence of uncomfortably warm homes has been appearing in UK consistently in the few last years. This paper discusses the overheating risk in four highly insulated homes in the UK where a mixed methods approach has been deployed to characterise areas of overheating risk, which have been found to occur with different degree of severity and different sources of risk, all related to design and

Williamson, T., E. Grant, A Hansen, D. Pisaniello and M. Andamon (2009), An Investigation of Potential Health Benefits from increasing Energy Efficiency Stringency Requirements Building Code of Australia Volumes One &Two. Report to the Building Code Board of Australia

An Investigation of Potential Health Benefits from increasing Energy Efficiency Stringency Requirements Building Code of Australia Volumes One &Two, 2009

In 2009, the Council of Australian Governments announced that it would request the Australian Building Codes Board to increase the energy efficiency provisions in the 2010 edition of the Building Code of Australia (BCA). These changes comprise a 6 Star energy rating, or equivalent, for new residential buildings; and significant increases in the energy efficiency requirement for all new commercial buildings. This report, through literature review, explores the possible positive and negative health related effects as temperature and other conditions change within a building to satisfy the energy efficiency provisions resulting from the proposed Building Code of Australia changes. As all new buildings have been required to satisfy BCA energy efficiency provisions for several years and it is likely that the most severe building defects that may impact on health conditions have already been eliminated; this report therefore focuses on the incremental benefits that might flow from an increase in the standard of construction. There is an association between weather and health. Weather refers to the ambient climatic conditions, not necessarily the conditions within buildings and temperature is generally taken as the main indicator of climate severity. Low or high temperatures may lead to human stress situations and result in increased morbidity and mortality. At a population level, heat-related health issues generally are at their lowest at moderate temperatures and increase with elevated or reduced temperature conditions. Populations in colder cities are more affected by warmer temperatures, whilst those in warmer cities notice a greater effect of colder temperatures. While both cold and hot temperatures increase the risk of mortality, hot temperatures are likely to have greater effects. The effects of extreme heat are more immediate, occurring within one or two days of a hot weather event. Periods of hot weather generally exacerbate underlying health conditions in vulnerable populations resulting in an increase in hospital admissions, emergency department visits and ambulance transports. Heat-related fatalities generally occur at an individual’s place of residence, which may be a private residence, an institution or the like. The incidences of heat-related mortality in other buildings appear to be low. Certain populations are more prone to temperature-associated illness than others. Vulnerable populations include the elderly, those with chronic or underlying medical conditions (e.g. kidney disease, respiratory or heart disease), mental illness, and the social disadvantaged. Many drugs can affect the thermoregulatory process and can contribute to heat stroke. The pharmacological effects of some medications may be a contributing factor to the increase in hospital admissions for renal and mental disorders observed during heat waves. Predictors of heat-related illness (including fatalities) are socioeconomic status (indicated by households without air conditioners or heaters), race and less educated individuals. Living in social isolation increases vulnerability. It is likely that in a changing climate, future temperature-related health issues will be dependent on the adaptive capacity of populations, including improvements to building design. The presence of air conditioning does not always guarantee its use, particularly with elderly householders with mobility or cognitive problems and those with financial concerns relating to energy costs. Fuel poverty may also be an issue but is under researched in the Australian context. No studies or field data were found that detail health benefits that might accrue from an incremental change in building energy-efficiency (eg a change in rating from 5 to 6 Stars for houses). In a New Zealand intervention study which upgraded the standard of housing by adding thermal insulation, health benefits were measured in terms of hospital admissions, days off school and days off work and the private cost saving per household of visits to general practitioners and mental health improvements. The study was limited to considering the winter time benefits. Applying a number of assumptions the findings have been extrapolated to the Australian context. An estimated health benefit value of 111.00perhouseholdfrommovingtoa5to6Starscanbecalculatedasapotentialmaximum.Thisfigurehoweverwouldmostlikelyapplytoonlythemostvulnerablehouseholds(eglowincomeandelderly).Theactualvalueislikelytobesignificantlylessbecausethemajorityofhouseholdswouldoff−setminimumtemperaturesbysomeformofheating.Assumingthepenetrationofheatersinnewhousestobethesameasthewholepopulationweestimatethebenefittobeamaximumvalueof111.00 per household from moving to a 5 to 6 Stars can be calculated as a potential maximum. This figure however would most likely apply to only the most vulnerable households (eg low income and elderly). The actual value is likely to be significantly less because the majority of households would off-set minimum temperatures by some form of heating. Assuming the penetration of heaters in new houses to be the same as the whole population we estimate the benefit to be a maximum value of 111.00perhouseholdfrommovingtoa5to6Starscanbecalculatedasapotentialmaximum.Thisfigurehoweverwouldmostlikelyapplytoonlythemostvulnerablehouseholds(eglowincomeandelderly).Theactualvalueislikelytobesignificantlylessbecausethemajorityofhouseholdswouldoffsetminimumtemperaturesbysomeformofheating.Assumingthepenetrationofheatersinnewhousestobethesameasthewholepopulationweestimatethebenefittobeamaximumvalueof9.50 per household. No data exists to estimate similar health benefits associated with higher (summertime) temperatures. With no appropriate data available the quantification of health benefits for the occupants of other buildings has not been attempted. This work has shown that a knowledge gap exists in this area with almost no research having been undertaken in Australia to establish potential health benefits of energy-efficient building improvements. The minimisation of temperature extremes within buildings, noise-related health impacts and air pollution related morbidity and mortality in an enlarging vulnerable population may yield significant savings to Australia’s health sector but as yet there is little evidence to back this proposition.