经过一个多世纪的使用后，老化系统正在加入美国国会大厦校园最古老的国会办公大楼大厦中持续的安全，健康，环境和操作问题。

The $659-million Phase 2 revitalization, a joint venture of Clark Construction and The Christman Co., set out to modernize and renovate the portion of the building that faces Independence Avenue—arguably the building’s most prominent facade. The project was part of the 10-year, five-phase Cannon House Office Building Renewal project, led by the Architect of the Capitol.

对于第2阶段，团队更换或维修了多个建筑系统，包括供暖，冷却，照明，管道，火灾和生命安全。还解决了可访问性和结构完整性问题。

此外，现有的五楼被拆除并用新的钢结构结构取代。原始的石材工程也在历史悠久的立面上恢复了。
在办公楼保持占用且功能齐全的同时，需要交付整个项目范围，这需要严格限制工作时间和现场访问。

克拉克（Clark）项目主管Tim Tesoriero表示，将建设活动与国会时间表保持一致，这被证明是该项目最具挑战性的方面，尤其是在历史悠久的恢复项目上。

他回忆说：“范围有些未知。”“恢复项目总是有无法预料的条件。直到发现一切之前，您真的不知道自己面临什么。”

在这些发现中，有危险物质在建筑物一楼的石膏墙上，需要完全减少和清除。与石膏匹配需要长时间的三件工艺，并花了30多天的时间才能正确治愈。有一次，有40多个石膏在建筑物中工作。

Tesoriero说：“石膏是高度专业的贸易，在此规模上并不是在华盛顿州地区普遍存在。”“石膏器必须具有很高的资格，因此我们将它们从东北和中大西洋中的各地带进来，以满足需求。”

Tesoriero说，该建筑物的系统几乎被完全替换了，很少有车道和现有路线被重复使用。

“Very few pathways could be preserved,” he says. “In the basement, there was a poured concrete plenum ceiling that had existing piping in it. We had to take out that entire ceiling and demolish everything. The structural components on Floors 1 through 4 were brick, so there was a lot of core drilling to create openings to allow these [systems] in.”

该建筑于1908年首次占领时，总共设有397个办公室。五年后，它已经超出了该空间，因此增加了51个房间，增加了屋顶结构并增加了五楼。五楼的一部分倾斜，这仅可用于存储。

As part of the Phase 2 renewal, the fifth floor was demolished and a new level was constructed with steel framing that ties directly into the existing structure. Although the fifth-floor structure was new, the marble flooring of the original corridor was preserved.

在拆除结构之前，团队用非染色工艺纸（2英寸）的非染色工艺纸进行修理，修补，密封和保护地板。刚性泡沫板和两层¾英寸。胶合板。一旦受到保护，新的五楼就可以围绕它建造。

Enr的一位法新利luck官说，该团队超越了以外，以保护历史悠久的大理石。

法官说：“我永远不会在地板上放置那么多层的保护层，但我想这是确保它不会被搞砸的一种方法。”

作为更新项目的一部分，历史悠久的外观也得到了恢复。所有原始的窗框都被拆除，并带到了一个异地研讨会，在那里他们被剥夺了以前的装饰，修复，修复和修补。当腰带上的工作正在进行中，现有的窗框仍在原位。现场进行了剥离，恢复和修补窗框。

Photo courtesy Clark Construction Group LLC

To restore the original interior solid wood doors, all original hardware was salvaged, cataloged and taken off site to be repaired and refinished. Door slabs were also removed and taken off site for repairs and refinishing.

原始的门框和套管被铅涂料剥去，并恢复和修补到位。然后将门板重新安装在其原始位置。原始硬件与新组件集成在一起，以促进现代功能和安全性，然后重新安装。

Judges were impressed that the project team logged more than 1.3 million work-hours with zero lost-time incidents. A “work plan” standard was established for all at-risk activities.

计划是由分包商well as the operations and safety teams. The plans were then reviewed by the owner’s safety personnel and ultimately approved by the House of Representatives’ construction management team. Those work plans became especially critical when dealing with lead paint and asbestos in areas immediately adjacent to active congressional office space.

为了在被占领的建筑物中工作，安装了临时的火灾墙壁，以将建筑活动与建筑物的活跃部分隔离开来。该项目团队与分包商，消防工程师，质量控制专业人员和消防元帅合作，创建了可以从建筑区域内建造的混合墙。

The strategy allowed the fire wall to be located within the interior door frames of the construction area instead of in occupied corridors. As a result, work took place without affecting occupied areas and ensured temporary walls remained hidden. Rather than seeing wire walls, building occupants saw closed office doors when walking through the corridor.

“They left the doors so, as people walked by, they looked like closed doors, but they were fire walls,” said one judge. “That stuck out in my head for the aesthetic for people still occupying the building.”