2008年，為容納迄今為止最廣泛的德國戰(zhàn)后藝術(shù)的私人收藏——斯多赫收藏系列，庫普斯墨赫美術(shù)館（MKM）提出的擴(kuò)建項(xiàng)目被提上日程。2013年，擴(kuò)建項(xiàng)目在斯多赫家族的牽頭下啟動(dòng)。赫爾佐格和德梅隆建筑事務(wù)受委托對當(dāng)前條件下該場地的潛力進(jìn)行了可行性研究，他們的成果將會(huì)帶給擴(kuò)建項(xiàng)目一個(gè)全新的開始。最初的擴(kuò)建思路是在筒倉塔頂建造一個(gè)發(fā)光的立方體，使之于遠(yuǎn)處可見，現(xiàn)在被徹底拋棄了。取而代之的是，建立一座全新建筑，其材料和尺度依據(jù)碼頭沿岸的歷史建筑磚塊結(jié)構(gòu)來呈現(xiàn)。新建部分以適宜得體的方式融入了碼頭建筑群，使既有的美術(shù)館綜合體成為了一個(gè)和諧優(yōu)美的整體。乍一看，似乎新建筑一直都坐落在那里。

新建筑由三部分組成，三個(gè)體塊高度分別為33.5米、30.5米和27.5米。在體塊關(guān)系、建筑高度和材料選擇上，新建部分都充分參照了現(xiàn)有建筑，延續(xù)了它們的特征，并圍繞其建造形成了這個(gè)統(tǒng)一和諧的整體。新建三部分中的兩個(gè)結(jié)構(gòu)為展覽空間，第三部分提供了通道，容納了公共設(shè)施和藝術(shù)品處理設(shè)施。擴(kuò)建部分共計(jì)五層，其中一層在地下，建筑面積約為4 900平方米，此外還有大約2 500平方米的展覽區(qū)。

擴(kuò)建部分的體塊關(guān)系受到“禁止在高速公路40米范圍內(nèi)建造”法令的嚴(yán)格限制，故而對可用區(qū)域進(jìn)行了充分的利用。展覽結(jié)構(gòu)的安排——三部分中最高的部分和與之相鄰的較小部分——與無建筑控制區(qū)的形態(tài)相呼應(yīng)，而第三部分的一個(gè)立面沿其邊界而建。項(xiàng)目額外的附加部分也是清晰可辨。在擴(kuò)建部分的最高點(diǎn)，也就是最大展覽區(qū)域的最頂層，新結(jié)構(gòu)的高度與現(xiàn)有的主要建筑維持在同一高度。

擴(kuò)建部分將通過筒倉內(nèi)的天橋在第一層和第二層與現(xiàn)有的展覽空間直接相連，方便來訪者暢通無阻地游覽整個(gè)美術(shù)館空間。相應(yīng)地，新建展覽部分的高度也以現(xiàn)有的畫廊為參照。筒倉不僅被改造為連接新舊的關(guān)鍵要素，其內(nèi)部也成為了一個(gè)獨(dú)特的展覽空間?？紤]到筒倉是庫普斯墨赫美術(shù)館作為紀(jì)念性工業(yè)建筑不可或缺的雕塑性組成部分，項(xiàng)目對筒倉原有的材料進(jìn)行了保留。長期以來，筒倉因其歷史和美學(xué)價(jià)值被世人所尊崇，如今，通過改造翻新，它還獲得了作為連接路徑和展示區(qū)域的全新功能。其內(nèi)部的六個(gè)小型筒倉已被移走，隨著地面層屋頂?shù)拈_放和聯(lián)通天橋的架設(shè)，整個(gè)空間都對來訪者直觀可見。同時(shí)，筒倉在美術(shù)館內(nèi)的一些其他展覽區(qū)域也可以看到。

全新的展覽空間回應(yīng)了庫普斯墨赫美術(shù)館作為19世紀(jì)和20世紀(jì)典型工業(yè)建筑設(shè)施的標(biāo)志性特征。在建筑和室內(nèi)設(shè)計(jì)上，畫廊空間都完美呼應(yīng)既有的展覽區(qū)域。新建部分最頂層的展覽區(qū)，即無法從現(xiàn)有美術(shù)館空間直接進(jìn)入的區(qū)域，由帶有頂部照明的棚屋結(jié)構(gòu)圍合。所有的展覽空間都進(jìn)行了多元化的靈活可變的操作考量。

筒倉配備加建的頂部建筑，仿佛他們自從1930年就佇立在這里。上層的加建部分有一個(gè)可以從碼頭長廊進(jìn)入的觀景平臺(tái)，它將賦予筒倉另一個(gè)新的功能。

The extension project was activated in 2013， with the Stro?her family as clients. A feasibility study undertaken by Herzog amp; de Meuron explored the potential of the site under current conditions. The resulting project constitutes a radical new start. The original idea of an illuminated cube balanced on the silo towers and visible from afar has been jettisoned. Instead， we propose to erect a building whose dimensions and materials accord with the sequence of historic brick structures lining the dockside. The new structure thus completes the existing museum complex in a visually appropriate way and forms a suitable conclusion to the row of buildings along the dock. At first glance， it might seem as though the new building had always been there.

The new structure consists of three parts with a height of approximately 33.5， 30.5 and 27.5 metres respectively. In terms of mass， height and materials they take their cue from the existing buildings， continuing them and rounding them off to form a harmonious whole. Two parts contain the exhibition areas， the third provides access and houses utilities and art handling facilities. With five levels， one below ground， floor space amounts to some 4，900 square metres， in addition to exhibition areas of roughly 2，500 square metres.

Massing was crucially influenced by a ban on building within forty metres of the autobahn. Optimum use is made of the available area. The arrangement of the exhibition structures – the tallest of the three parts and the smaller one adjoining it – echoes the course of the building-free zone， while one elevation of the third part runs along its boundary. The additively composed parts remain distinctly legible. At its tallest point （the uppermost level of the larger exhibition component）， the new structure is related in height to the main existing building.

The extension is to be linked directly to the existing exhibition spaces by bridges through the silos at the first and second upper levels， facilitating uninterrupted visitor access throughout the museum. Similarly， the height of the new exhibition areas takes its cue from the existing galleries. The silos will not only be converted into elements connecting the old with the new; they will also house distinctive exhibition spaces. Their original materials are to be retained， however， because the silos are an indispensable ‘sculptural’ component of the Ku?ppersmu?hle as an industrial monument. Long reduced to this historical and aesthetic aspect， they acquire a new function through refurbishment as access links and display areas. Six inner silos had already been removed. Now， with the ground-floor ceiling opened up and the insertion of the bridges， the entire space will be visible to visitors. In addition， the silos can be seen from some of the exhibition areas.

The new exhibition areas echo the overall additive character of the Ku?ppersmu?hle as a typical industrial facility of the nineteenth and twentieth centuries. In their architecture and interior design， the galleries echo the existing exhibition spaces. The uppermost display area， which is not directly accessible from the existing building， consists of a visible shed construction with top-lighting. All exhibition levels have a spatial arrangement facilitating flexible multiple uses.

The silos are to be fitted out with a superstructure， as they were original， in the 1930s. Featuring a viewing platform accessible from the dockside promenade， the superstructure will grant the silos yet another new function.