Research of some aspects of relation between ecology and energy efficiency in traditional architecture

Pastaruoju metu vis svarbesniu reikalavimu pastato kokybei tampa ekologiškumo kriterijus, kuris tiesiogiai siejasi su jo energiniu efektyvumu. Tuo tarpu architektūros ir inžinerijos principai, kuriuos taikant statiniai taptų energiškai efektyvūs, ne visada gali būti vadinami ekologiškais, nes jų taikymas dažnai prieštarauja tokioms sampratoms kaip vietinių žaliavų naudojimas, mažai gamybos bei transportavimo energijos reikalaujanti statyba, savaime suyrančios arba antram ciklui panaudojamos medžiagos. Tradicinėje, ypač kaimo statyboje, šie principai galiojo natūraliai, bet retas tradicinis pastatas dėl dažnai prastesnių jo atitvarų fizikinių savybių gali būti vadinamas energiškai efektyviu. Europos sąjungos direktyva 2010/31/ES numato, jog po 2020 m. visi nauji pastatai turi atitikti beveik nulinį energijos poreikio reikalavimą. Šiame kontekste ir esant minėtajai priešpriešai, pristatomame tyrime sulyginta tradicinių pastatų energinį efektyvumą užtikrinančių priemonių nauda (išreiškiama sutaupytos energijos kiekiu per pastato gyvavimo laikotarpį) ir energijos „išlaidos“, reikalingos šioms priemonėms įdiegti. Sulyginus keletą skirtingų tradicinių pastatų sprendimų, nustatoma, kokie istoriškai susiklostę „pasyvūs“ pastatų formavimo principai yra efektyviausi energijos taupymo aspektu.The evolution of traditional buildings reflects the uninterrupted development and the assimilation of the most worked out structural and architectural solutions. The new requirements of the EU regulations (from 2020 all new buildings must meet the requirement of almost zero-energy level) as well as applicable laws in Lithuania (the Lithuanian building regulations STR), however, set strict requirements which are difficult to apply to the traditional architecture. On the other hand, not all measures aimed at building energy efficiency are compatible with the concept of ecology (usually attributable to the traditional architecture). Due to the aforementioned confrontation, the purpose of this research is to use the comparative analysis method to examine some of the measures determining energy efficiency of a building and the rationality of these measures in the context of building’s lifecycle (which consists of construction, operation and demolition stages). One of the tested measures in this issue is the improvement of thermal properties of external envelope’s elements to meet the requirements of existing building regulations (according STR2.05.01: 2005). The research examines the ability of the improved thermal resistance of traditional buildings’ external envelope in assessing the benefits during the operation stage. The rationality is determined by comparing the energy savings during fifty-yearlong lifespan (STR2.01.09: 2005) with the energy needed to produce the material (i.e. embodied energy). After comparing several different thermal insulation materials, e.g. mineral wool, EPS panels, straw insulation, the best solution is found. Besides the aforementioned, this research examines some principles of "passive design" applied in traditional buildings of various Lithuanian ethnographic regions. Four buildings varying in size, plan configuration, external envelope area, etc. were analyzed: "Viengale Pirkia" and "Dvigale Pirkia" from Dzūkija, "Troba" and "Kryžiavinis" houses from Žemaitija. The research is based on the methodology of evaluation of geometric efficiency by Parasonis, Keizikas et al. (2012a, b). The findings allow us to make the following conclusions: the research has indicated that the energy savings of insulated buildings (per lifetime period) are several times bigger than the energy needed to produce the applied insulation materials; based on the ratio of embodied energy and saved energy of tested materials, the research shows that the straw is the most rational insulation. It is also characterized as being a natural material as well as eliminating the additional energy inputs for recycling. However, it requires larger structures capable to withstand higher loads; the research of geometric parameters of traditional houses has shown that the usage envelopes of "Troba" and "Kryžiavinis" houses is most efficient: "Troba" because of the most compact volume and "Kryžiavinis" because of the largest hosted floor area; the comparative indicators of buildings compactness show that energy is saved more effectively in the examples of traditional volumetric and plan solutions of buildings (usually with pitched roofs), when comparing them to modern houses with flat roofs. Therefore, seeking minimum usage of materials for construction and improving energy efficiency during operation period, the traditional pitched roof is the best solution