Slate provides an 'elegant and unique skin' for office building

August 21, 2001
/ Print / Reprints /
/ Text Size+
For an office building located at 1900 K Street in the heart of Washington DC's Central Business District, code restrictions limited the design options, but the architects at Cesar Pelli & Associates made the most of what they had. By elaborating on the requirements with steel, glass and slate, they were able to create some interesting design aspects.

Despite the restrictions, the building was successfully designed to attract attention to itself. "We designed an elegant and unique skin for the building, which makes it stand out from its context," said Susana La Porta Drago of Cesar Pelli & Associates. "Several elements allowed us to achieve this: the glassy proportions of the wall, the sheen of the stainless steel and the green of the stone panels. The wall design has an underlying matrix where the horizontal stone bands are balanced by a rhythm of single and double stainless steel vertical bullnoses."

By further enhancing the required elements, the architects were able to create an ornamental, yet efficient, design. "Our massing options for this project were very limited by code restrictions," Drago said. "However, we thought that the required setbacks and the corner condition could be elaborated into some interesting design features. The corner became a very elegant curved piece; it was very important to us to define this corner with curved stone panels held by curved stainless steel mullions. The setbacks expressed the structure of the building by exposing its stainless steel clad columns."

Stone was selected for this project early on because of its durability and its ability to convey a sense of class and quality, according to Drago. "We were interested in green stones, and we looked at several slates," she said. "Kirkstone slate was very hard and had a dense consistency, which made it a good option for a curtainwall application."

Kirkstone Sea Green slate was specified for the project. Formerly known as Westmorland Green slate, this stone has a beautiful dark green sea color, according to the company. It is made from volcanic ash compressed over thousands of years in the English Lake District. Despite being called a slate, this stone is much harder than other slates and is almost comparable to granite for its durability, Kirkstone reports.

The 1900 K Street project incorporated a total of 5,500 square feet of Kirkstone Sea Green honed slate consisting of 5-foot x 2-foot x 11¿inch straight cladding and 5-foot x 2-foot x 3-inch curved cladding. The stone panels had 6,500 linear feet of kerfs at the top and bottom edges, and they were supported with metal angles.

"We designed a unitized curtainwall system, which means that the curtain-wall units are fabricated and assembled at the shop," Drago said. ""The curtainwall fabricator, Antamex, installed the stone panels at their shop in Toronto. This makes the quality control process significantly easier because most of the work can be inspected at the shop before being shipped to the site. The only work that took place at the site was the installation of the finished units."

Did you enjoy this article? Click here to subscribe to Stone World 

Recent Articles by Jill Critchley

You must login or register in order to post a comment.



Image Galleries

The Stone Fashion Show at Marmomacc in Verona

As usual, stone suppliers from Italy and around the world relied on the Marmomacc fair to showcase some of the latest stone materials to the international marketplace. The following is a look at just some of the stone materials on display in Verona.

Stone World Magazine

Stone World September 2014 cover

2014 September

In this issue of Stone World, we have a Report from Europe, which includes a series of articles about the quarries and stone processing operations that SW editor Jennifer Adams visited as part of the Marmomacc Stone Academy.

Table Of Contents Subscribe

Contemporary Stone & Tile Design Magazine

CSTD Fall 2014 cover

2014 Fall

In this issue of Contemporary Stone & Tile Design, we take a look at the latest developments in TPT, with a feature article and you can read more comments from Waldrep on this subject as well as other industry professionals.

Table Of Contents Subscribe


Are you aware of the new stone standard – ANSI/NSC 373 Sustainability Assessment for Natural Dimension Stone?
View Results Poll Archive

The Stone World Store

How to Polish & Restore Marble Flooring

This video will show you step-by-step how to resurface and polish marble flooring from grinding and removing lippage and scratches to achieving a highly reflective polish.

More Products

Stone Guide

2014 Stone World Stone Guide

The directory for Stone, Equipment and Supplies - the single information resource readers turn to.

Stone Industry Education

stone industry educationStone Industry Education is sponsored by Stone World Magazine and Marble Institute of America. The SIE events will help you: strengthen your skills, build your business, and  increase profit in your shop.  Check out to register for upcoming fabricator and installer seminars.


facebook logo Twitter  YouTubeGoogle+