Many mu­ni­cip­al­it­ies, par­tic­u­larly in high-dens­ity urb­an areas, are tack­ling the ur­gent task of provid­ing more af­ford­able hous­ing. Al­though gov­ern­ment sub­sidies are of­ten avail­able for en­ergy-ef­fi­cient build­ings, in­vest­ments in en­ergy ef­fi­ciency es­pe­cially are per­ceived to be a ma­jor factor for in­creased costs by the prop­erty de­ve­lopers. "Gen­er­ally speak­ing, it is not enough to only con­sider the in­vest­ment costs for con­struc­tion. The aux­il­i­ary costs are of cru­cial im­port­ance for so­cially ac­cept­able rents," ex­plains Oliv­er Kah of the Pass­ive House In­sti­tu­te. The ses­sion of the Re­search Group on so­cial hous­ing ini­ti­ated by the Pass­ive House In­sti­tu­te dealt with both cost seg­ments.

Act­ive cli­mate pro­tec­tion

Dr Wolfgang Feist, founder of the Pass­ive House In­sti­tu­te, has poin­ted out that en­ergy ef­fi­cient hous­ing con­struc­tion helps in achiev­ing cli­mate pro­tec­tion ob­ject­ives. "No­tice­able suc­cess has already been achieved through bet­ter en­ergy ef­fi­ciency. These solu­tions must now be ap­plied with com­mit­ment."

Sav­ings po­ten­tials

Dur­ing the 55th Ses­sion of the Re­search Group for cost-ef­fect­ive Pass­ive Houses, Es­th­er Goll­witzer of the Pass­ive House In­sti­tu­te iden­ti­fied the sav­ing po­ten­tial and cost drivers for hous­ing con­struc­tion. Based on the ex­ample of already real­ised multi-storey res­id­en­tial build­ings, she showed that the con­struc­tion costs fluc­tu­ate con­sid­er­ably even with the same en­ergy stand­ard. This might be due to dif­fer­ent build­ing designs, for ex­ample. However, Goll­witzer em­phas­ised that en­ergy ef­fi­ciency meas­ures have only a small im­pact on the total costs of the build­ing and men­tioned that these ad­di­tion­al costs amount to about four to sev­en per cent for build­ing to the Pass­ive House stand­ard.

At­tract­ive sub­sidy pro­grammes

"But these in­vest­ments for high­er en­ergy ef­fi­ciency can of­ten be re­duced sig­ni­fic­antly through sub­sidy pro­grammes, in con­trast to the  in­creas­ing costs for build­ing fa­cil­it­ies," ex­plained Oliv­er Kah of the Pass­ive House In­sti­tu­te. In his present­a­tion, Kah ex­amined the total costs for a new build­ing. He pre­cisely cal­cu­lated how prices for the build­ing land or an un­der­ground gar­age are rising, and how costs for build­ing more en­ergy ef­fi­ciently, in­clud­ing a good level of in­su­la­tion, can af­fect the costs for the DIN 276 con­struc­tion cost group 300-400 and hence also the rent later on.

Happy res­id­ents

Ac­cord­ing to Kah, en­ergy ef­fi­cient build­ings are at­tract­ive for res­id­ents as well. Hous­ing con­struc­tion com­pan­ies re­port that the risk of va­cant prop­er­ties is very small in the case of Pass­ive House homes due to their low aux­il­i­ary costs and the high stand­ard of liv­ing com­fort at the same time. Marc Großk­los from the IWU (In­sti­tu­te of Hous­ing and the En­vir­on­ment) and Pass­ive House de­sign­er Folk­er Rasch dis­cussed the Passivhaus­Sozi­alPlus in Darm­stadt as a key fo­cus of the Re­search Group.

Na­tion­wide mod­el pro­ject

The Passivhaus­Sozi­alPlus in Darm­stadt is a na­tion­wide mod­el pro­ject and was also the fo­cus of an ex­cur­sion dur­ing the Pass­ive House Open Days. This so­cial hous­ing pro­ject aims for aux­il­i­ary rent­al costs of two Euros per square metre of liv­ing space on av­er­age. These costs will be charged as a fixed fee and will in­clude the costs for elec­tri­city, hot wa­ter and in­ter­net use. The ex­cur­sion’s par­ti­cipants were im­pressed by this pro­ject which con­sists of two apart­ment blocks, of which one is a ret­ro­fit­ted build­ing and the oth­er one is a new build. Both build­ings are equipped with a photo­vol­ta­ic sys­tem and bat­tery stor­age.

Sub­sidies are avail­able

For the En­ergy Agency of the state of Hesse (LEA), Chris­ti­an Kuhl­mann out­lined the sub­sidies avail­able for ex­tremely en­ergy ef­fi­cient build­ings, in­clud­ing those for mod­ern­isa­tion of ex­ist­ing build­ings to the Pass­ive House stand­ard. Kuhl­mann con­firmed that nu­mer­ous grants are avail­able. The non-profit hous­ing de­vel­op­ment as­so­ci­ation Neue Heimat Tir­ol (NHT) spe­cial­ises in so­cial hous­ing. Har­ald Malzer presen­ted vari­ous pro­jects of the NHT in­clud­ing the mod­el 5-Euro-Miete ("5 euro rent") of a Pass­ive House build­ing in Schwaz, Tyr­ol.

Works of art for so­cial hous­ing

The 18 apart­ments in this Pass­ive House pro­ject are ren­ted out by the NHT for a monthly amount of just five Euros per square metre to cov­er costs, in­clud­ing heat­ing. The NHT also en­deav­ours to cre­ate a wel­com­ing at­mo­sphere in the build­ings and in­cor­por­ates a piece of art in­to each prop­erty to en­hance this, says Malzer.

Most eco­nom­ic­ally ef­fi­cient op­tion

Ralf Wern­er presen­ted new build­ings and en­ergy ret­ro­fits of the Wohn­bau Gießen. He poin­ted out that ret­ro­fit­ting with Pass­ive House com­pon­ents rep­res­ents the most eco­nom­ic­ally ef­fi­cient vari­ant for Wohn­bau Gießen if sub­sidy pro­grammes can be ac­cessed. At the end of the Re­search Group ses­sion, Pass­ive House In­sti­tu­te staff presen­ted proven solu­tions for an en­ergy ef­fi­cient build­ing en­vel­ope and for cent­ral­ised and de­cent­ral­ised home vent­il­a­tion sys­tems with heat re­cov­ery.

Next Re­search Group ses­sion in May

The find­ings of the Re­search Group will be pub­lished in a pro­tocol (in Ger­man). To­geth­er with the Hes­si­an Min­istry of Eco­nom­ic Af­fairs, En­ergy, Trans­port and Hous­ing, the Ger­man state of Hesse is the spon­sor of the Re­search Group ses­sions 55 to 57. The 56th ses­sion of the Re­search Group for cost-ef­fect­ive Pass­ive Houses will take place on 14 May 2020 and will be on the top­ic "En­ergy ef­fi­ciency and re­new­able en­ergy: Con­flict of goals or syn­ergy?"