Abstract
Introduction
In Japan, vacancy rates has been rapidly increasing. Since provincial cities would collapse if we allowed the situation, various measures are being considered. Among them, one of the most effective measure is renovation for existing houses to continue to live and to be distributed.
Although many studies about renovation and retrofit have been conducted, there is not many knowledge for renovation with thick insulation. It is essential to improve the thermal environment with thick insulation when we implement renovation in cold climate. Generally, Improvement of thermal performance with insulation is so costly that funding is difficult through the normal scheme. The R housing projects have been conducted over the past decade in Hokkaido. Housings are needed to be renovated with the thick insulation, Q-value is less than 1.6. We are able to use the normal housing loan when we renovate housings under the project. Moreover, it is possible to receive the subsidy. A number of housing in this scheme has been renovated.
In this report, we carried out the questionnaire survey and numerical simulation to analyze an actual situation of energy consumption and living environment in thermal renovated residential houses. The result indicates that the resale business after renovation is valid as promotion method for existing houses.
Method
In this report, we conducted the below survey and analyzed the results.
1. Questionnaire survey on living environment and energy consumption in the residents built by R housing project. The purpose of the survey are to analyze the actual situation of the living environment and energy consumption in those housings.
2. Numerical simulation on energy consumption in the thermal renovated houses. The numerical simulations were conducted to analyze the effect of thermal renovation.
3 Questionnaire survey on optimization of housing allocation by relocation. Another questionnaire survey was conducted to analyze the intention how the households living in detached houses manage their own houses in K city, Hokkaido
Results and Discussion
The result of former questionnaire survey indicates that even the thermal performance of renovated houses are enough to avoid the dew, some houses have dews and mold problem. The main reason is the difference of the temperature between heating space and non-heating space such as bedroom and bathroom. Households who live in bigger houses than their size heat their houses partially to save the heating cost. Moreover, the thermal performance calculated by the heating energy and the temperature difference were similar with the designed value in the case of Ha and K. Although the relationship did not exist in the case of S that has been used by elderly couple. The house is too big for the couple to keep warm uniformly. Then we recommend sell-redistribution style when we have to renovate housings.
The results of the numerical simulation indicate that change of wall insulation and window are effective on the reduction of heating energy consumption. The heating energies are about half, when the high performance model is used.
Finally, we analyzed the intention how to deal their housings in the near future in K city by the questionnaire survey. Fig. 12 and 14 shows that 70% of elderly households want to live their own house in future. The promotion of sell-redistribution style improves QOL of elderly households such as heating cost and indoor environment.
