座落於傑魯薩勒姆斯卡街的艾迪森變電所，1926年由李布拉 (F.A. Libra) 建築師設計，原本的變電所功能一直維持到1990年代。後來因為現代科技的演進，變電所遷移到地下室，建物就得以空出來作商業使用。當時正值功能主義初期，再考量到建物本身的功能，這棟建築結構相對之下顯得格外複雜：每個樓層的面積都不盡相同。建築師賦予建築量體靈活的變化，所衍生的豐富性，令人聯想到建構主義建築所帶來的影響，也或可視其為功能主義後期的提早演繹。
建築的側面可說是最早開始把立面外推的案例，目的是讓室內空間保持通風涼爽；類似的設計手法一直到1970年代才開始得到運用。艾迪森變電所因為其原有功能特殊，所產生的內部空間也獨樹一幟。建築的承重結構與天花板的尺度都反映出沈重的負載，支撐天花板的鋼筋混凝土樑網格也異常地密集。天花板由槽型構件組成複雜的剖面，裡面有內藏電纜的垂直管線。原本的內部格局是以莫尼耶氏鋼筋混凝土牆分隔，從樓梯通過兩道走廊可以進入排成四列的小隔間。
改建與擴建
整修時的規劃，是把一樓改建為可供承租的一般零售空間，原上方樓層用作辦公室，增建的空間則設計成公寓。建案尚在施工期間，就賣給了WPB顧問公司作為企業總部，一樓留給 WPB Capital 合作銀行使用。在調整設計因應新業主需求的期間暫停施工。
增建的部分被設計成連接前立面的屋頂結構，向傑魯薩勒姆斯卡街的方向微挪，呼應建築原有的構圖，也刻意跟原來的建築形成對比。
建築進行整修的部分，主要的改造是拆掉原來的小隔間，並且把位於前立面後方的內牆開窗拉寬。我們試圖維持主切面裡，開放式內部空間大開大闊的尺度，以及由巨型冠樑支撐的天花板。所幸，投資人也體認到建築的龐大潛能，決定讓所有的工作空間維持其開放性。我們嚴謹地整修並善用建築原有的元素，力求使建築不失其真實性。
其中最重要的特色包括樓梯欄杆、室內金屬門及玻璃門、還有簡潔的金屬玻璃窗。新裝的內窗使用單層玻璃，依此可分辨出原有及新加的元素，至於外立面則維持原狀。地面層的金屬閘門也是原有的元素加以整修，過了閘門就到了通往商店的新建玻璃入口。位於角落的建築主入口尺寸拉大到跟原來的鄰近入口一樣。施工期間在剝除外層灰泥粉刷時，發現前立面的鋼筋混凝土已經嚴重受損。最後，我們決定加上一層兩公分的聚苯乙烯樹脂來修復裂隙，把立面結構的延展及所造成的影響穩定控制下來。
沿著窄巷一側的立面而建的三段式鋼筋混凝土階梯，我們把它再往上延伸一個樓層，通往建築上方的新結構體。新舊鋼筋混凝土階梯、走廊地板、前廳和廁所都使用光滑的磨石子作為表面材質。
我們在每個案子裡都很注重灰泥粉刷的品質，本案亦不例外。 使用標準化的灰泥配比，經過磨光及疏水性塗層或臘處理後，表面極為光滑，甚至有時還可以刷洗，顏色則視所使用的灰泥成分而分別透出自然的白、赭或灰色調。
Edison transformer station in Prague
A symbol of the technical and social dynamism of the 20th century
The Edison transformer station in Jeruzalemska Street, designed by architect F. A. Libra in 1926, served its original function until the 1990s.
Modernised technology allowed the transformer station to move into the basement and the building was freed up for commercial purposes.
For the period of early functionalism and given its function the building is an unusually complicated structure: no two floors have the same area.
The architect used the contract to play a dynamic game with the building’s volume. This richness may bring to mind the influence of constructivist architecture or may be viewed as an early manifestation of the creations of late functionalism.
The construction of the side facade ranks the building among the first with a forward-set facade, whose function was to ventilate and cool the internal spaces. Similar design solutions did not start being used until the 1970s.
The Edison transformer station is also unique for the specific appearance of its interior, which derived from its original function. Both the load-bearing structure and ceilings are dimensioned for heavy loads. The ceilings are held up by an unusually dense grid of high, reinforced concrete girders.
The ceiling panels have a complicated side profile made up of channels and contained a number of vertical ducts that cables were run through.
Originally the building was divided by Monier’s reinforced concrete walls into four rows of cubicles that were reachable via two corridors from the stairwell.
Conversion and new addition
The renovation project sought to convert the building into a universal building with leasable retail spaces on the ground floor, offices on the original upper floors and flats in an added structure. During the building work the property was sold to WPB Consulting, a. s., which chose it for its head office, with the ground floor to be used by the cooperate savings bank WPB Capital. The building work was suspended while the project was adjusted to suit the new owner’s requirements.
The addition is designed as a roof structure attached to the anterior side facade, shifted slightly towards Jeruzalemska Street in line with the
building’s original composition. It is a deliberate contrast to the original building.
The main modifications in the renovated part of the building were the demolition of the cubicles and widening of the window apertures in the internal side perimeter wall behind the anterior facade. We tried to preserve the generous scale of the open interior of the main section, with its ceiling of massive girders. Fortunately, the investor grasped this potential of the building and decided that all workplaces should be open-space.
We preserved the building’s authenticity by making rigorous use of renovated original features. The most important features included the staircase banister, the interior metal and glass doors, and the simply glazed metal windows. The new interior windows are single-paned so that the original and new features are distinguishable and the appearance of the outer facade is left unchanged. The metal gate on the ground floor is also original and renovated; behind this, there are new glass portals with entrances to the shops. The building’s main entrance in the corner bay was enlarged to the original size of the neighbouring portals.
Stripping the external plastering during the building work revealed considerable damage to the reinforced concrete anterior facade. In the end, we decided to repair the cracks by adding a 2 cm polystyrene layer that stabilises the stretching of the facade structure and its consequences.
The three-flight reinforced concrete staircase aligned to the narrow street facade was extended upwards by one floor to serve the new structure on top of the building. Both the original and new reinforced concrete stairs and the floors of the corridors, vestibule, and toilets were finished with smooth-grain cast terrazzo.
As we do in our other projects, we placed great emphasis on quality plastering. We use a standard range of plaster mixes, which, when they have been polished and preserved with a hydrophobic coating or wax, create a very smooth and in some cases washable surface in subtle natural shades of white, ochre and grey, depending on the plaster used.