This study analysed renovation measures implemented with ARA renovation subsidy in Finland in multifamily apartment buildings. Measured energy data was used to calibrate the energy simulation model of the most typical renovated building from the 1970 s. For the reference building, a comprehensive set of renovation packages were applied to assess the performance of ARA grants. It was noticed that official energy performance certificates (EPC) overestimated before the renovation energy use as well as energy saving by a factor of almost 2. It was notable that in calculated EPCs, after renovation, EP-value was higher than before renovation, EP-value based on measured energy use. The main reasons for faulty energy calculations were strong overestimations in the building leakage rate and ventilation airflow rate. Renovation packages reduced EP-value by 8 % to 27 %, including lighting and appliances. Those using district heat resulted in a small increase in electricity with a flat duration curve, but the combined ground source and exhaust air heat pump showed the highest peak electricity power increase by factor 6. Exhaust air heat pump, window replacement and photovoltaic were the most cost-effective options, while packages with additional insulation faced considerably higher costs than the sum of ARA support and monthly savings could cover bank loans; thus, ARA support was clearly too small to support deep renovation. The need to improve the accuracy of EPCs in assessing energy performance to facilitate more effective financial support was a finding that can be important for any support scheme to secure the necessary funding for renovation.

中文翻译：

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芬兰多户公寓楼能源改造补贴：经验教训和最佳实践

本研究分析了芬兰利用 ARA 改造补贴对多户公寓楼实施的改造措施。使用测量的能源数据来校准 20 世纪 70 年代最典型的翻新建筑的能源模拟模型。对于参考建筑，采用了一套全面的整修方案来评估 ARA 拨款的绩效。人们注意到，官方能源绩效证书（EPC）高估了改造前的能源使用量以及节能效果近2倍。值得注意的是，在计算的EPC中，改造后的EP值高于改造前的EP值。 -基于测量的能源使用的值。能源计算错误的主要原因是对建筑泄漏率和通风风量的严重高估。整修包将 EP 值降低了 8% 至 27%，其中包括照明和电器。使用区域供热的发电量略有增加，且持续时间曲线平坦，但地源热泵和废气热泵组合的峰值电力增幅最高，增加了 6 倍。废气热泵、更换窗户和光伏发电增幅最大。具有成本效益的选择，而具有额外隔热功能的套餐面临的成本远高于 ARA 支持和每月储蓄可支付银行贷款的总和；因此，ARA 的支持显然太小，无法支持深度改造。需要提高 EPC 评估能源绩效的准确性，以促进更有效的财务支持，这一发现对于任何确保翻修所需资金的支持计划都很重要。