Fig . 3 . Measurements of Indoor Temperatures in one week of winter ( left ) and leakage of building trough blower-door test ( right ) in the case 6 .
On the other hand , adults occupants of each home were questioned about room use and a standard survey was applied to determine thermal satisfaction levels . More in-depth interviews were also carried out as well as daily following over the summer and winter periods to review occupation patterns and comfort perception and expectations . Firstly , this revealed diverse degrees of conformity amongst the family groups , with significant generational differences in habits and perceptions . Younger residents displayed a greater need for privacy and adequate thermal conditions . Overall , comfort levels in the homes were considered adequate but there was substantial disparity depending on the summer and winter seasons , the different rooms and storeys involved solar orientation and the activities taking place . Layout also proved important to comfort levels . Specific structured heating routines were identified ( GARCIA et al , 2013 ).
Retrofit Studies
In the homes studied , the possibility of retrofitting to improve thermal performance was also assessed , using a strategy analysing solutions through dynamic simulation ( GARCIA et al , 2014a ). This was based on a baseline simulation with adjustments to the air change rate ( to 1.6ACH ) and adaptive comfort temperatures ( 18 º C-24 ° C with 70 % RH ) and occupancy rates ( 40W / m2 ). These figures match regular conditions for the typology of the zone according the monitoring and surveys done , taking into account fuel costs for space heating in winter ( the main domestic expense ) converted to energy demand . The amount of total energy demand for heating in winter ( May to October ) in the homes studied was between 30 kwh / m2 to 80 kwh / m2 , according age of construction ( higher is older houses ), that corresponds around 40 % of total energy demand per house . In line with recommendations from general studies and previous local experiences , the improvement alternatives that were considered by this study focused on increase air tightness and thermal insulation of the building envelope . Measures included sealing doors , windows and wall perforations , putting additional exterior protection on walls and ceilings and replacing existing single-glass windows with double-glazing . Other modifications , such as increasing or reducing window openings according to orientation , incorporating skylights or greenhouse and improving floor ventilation or insulation did not offer better performance results .
The budget of the solutions was calculated for each home according to market prices for materials and labour costs . An efficiency value was then determined in relation to the total cost versus equivalent saving in fuel expenses . General limit budget were then established for retrofitting , corresponding to 5 %, 10 % and 15 % of the commercial value of each home in order to offer different alternatives ( 10 % corresponds to the state subsidy for this activity ). The solutions
596 ZEMCH 2015 | International Conference | Bari - Lecce , Italy