WILLIS FABER DUMAS INSURANCE HEADQUARTERS, 1970-1975

Ipswich, Suffolk, England

Norman Foster

Description

This early work of Foster Associates establishes many precedents of what has come to be called “High Tech” architecture. Situated on a difficult site in the urban con­text of Ipswich, England, the Willis Faber Dumas Insurance Headquarters (now Willis Corroon) was designed to attract company personnel from the firm’s London office. The solution features a semipublic first floor with leisure facilities and two office floors above. The building is capped by a penthouse restaurant and roof garden.

With a deep floor plan that extends to the sidewalk limits of the site, the office spaces are penetrated by an escalator circulation system that serves all four levels and doubles as a light well. The roof garden restaurant thus becomes a light monitor to introduce daylight to the cen­tral areas of the deep-plan office floors. In the overcast cli­mate of the eastern coast of England, a suspended mullionless glass skin provides a floor-to-ceiling outside view and natural light.

The grand stairway of the escalator and the distrib­uted exit stairs serve to organize the interior arrangement of office space. A 5 ft deep perimeter circulation path is cantilevered outside the last column bay. This scheme buffers the workstations from the less controlled glass weatherskin where harsh sun or cold glass surfaces may be uncomfortable for prolonged periods of time.

TABLE 6.4 Fact Sheet
Project	Building Name Client City Lat/Long/Elev	Willis Faber Dumas Insurance Headquarters Willis Faber Dumas Insurance (now Willis Corroon) Ipswich, Suffolk, England 52.06 N 01.15 E, 95 ft (29 m)
Team	Architect Structural Engineer Mechanical Engineer Glazing Acoustics Quantity Surveyors General Contractor	Norman Foster Anthony Hunt Associates Foster Associates Pilkington Acoustics Sound Research Davis Belfield & Everest Bovis Constructor Ltd.
General	Time Line Floor Area Occupants Cost Cost, 1995 dollars Stories Plan	Design 1970 to 1972, building opened June 2,1975. 226,041 ft2 (21,000 m2). 1350. £4,982,062 or U. S. $11,361,094. $32,184,403 or $142/ft2. Three stories above grade plus a penthouse restaurant and roof garden. Footprint covers entire site up to sidewalk.
Site	Site Description Parking, Cars	Irregular shape, 1.7 acre (7000 m2) urban site. Parking garage across street from building.
Structure	Foundation Vertical Members Horizontal Spans Special Features	Slab elevated above poor soil on bored concrete piers. Circular concrete columns on a 46 ft x 46 ft grid. Ground and first floor are 39.4 in. (1 m) diameter. Higher levels have 31.5 in. (800 mm) diameter columns. Concrete waffle slab, 27.6 in. thick (700 mm); 5 ft (1.5 m) cantilever at perimeter. The interior column grid is complemented by a ring of closer-spaced columns at the building perimeter that define the building shape.
Envelope	Glass and Glazing Cladding Roof Special Features	There are 930 panels of 2.0 m x 2.5 m of 12 mm thick glass (6.6 ft x 8.2 ft x 0.5 in.). Interior vertical fins of 19 mm (0.74 in.) glass provide lateral wind resistance. All glass, Pilkington Armor plate Antisun bronze reflective. Single-ply rubber roofing with glass mat and sod. Glass panels are all hung from roof and connected with 6.5-in. square brass plates and stainless steel screws.
HVAC	Equipment Cooling Type Distribution Duct Type Vertical Chases Special Features	Centrifugal refrigeration chilled water and boilers. Fan coil and forced air. Supply through strip diffusers in ceiling grid. Return plenum through light fixtures. Concealed single duct. Toilet room modules on office floors provide stacked mechanical areas. Mechanical system is exposed through glazing to sidewalk at grade level.
Interior	Partitions Finishes Vertical Circulation Furniture Lighting Special Features	Open plan. Rubber flooring on first level. Green carpet on office levels. Escalator lobby rises three levels to receive toplighting from restaurant. Herman Miller. Parabolic strip fluorescent downlighting in aluminum louver ceiling. Ground level contains leisure activity spaces (pool, coffee bar, gym), as well as mechanical.

930 panels of 2.0m x 2.5 m of 12-mm thick glass (6.6ft x 8.2ft x 0.5 in.). Interior vertical fins of

19- mm (0.74 in.) glass provide lateral wind resistance. Bronze reflective glass panels are all hung from roof and connected with 6.5 in. square brass plates and stainless steel screws.

Escalator lobby rises three levels to receive toplighting from restaurant. Single-ply rubber roofing with sod covering.

Concrete waffle slab, 27.6 in. thick (700 mm). Five foot (1.5 m) cantilever at perimeter.

-Circular concrete columns on a 46-ft x 46-ft grid. Ground and first floor are 39.4 in.(1 m) diameter. Higher levels have 31.5 in. (800mm) diameter columns. The interior column grid is complemented by a ring of closer spaced columns at the building perimeter that define the building shape.

Mechanical system is exposed through glazing to sidewalk at grade level. Centrifugal refrigeration chilled water and boilers. Concealed single duct forced air distribution from fan coil. Supply through strip diffusers in ceiling grid. Return-air ceiling plenum through light fixtures.

Slab elevated above poor soil on bored concrete piers.

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O’ 20′ 40*

Program

Client

Willis Faber Dumas (now Willis Coroon) is the world’s third-largest insurance firm. The company is an under­writer for Lloyd’s of London and has a large interest in maritime risks. Among its insured have been the Titanic and the lunar exploration Moon Buggy.

In August 1971 the firm decided to reorganize its busi­ness operations and decentralize its London-based admin­istrative departments. Ipswich was attractive for its affordable real estate, bustling port, economic vitality, and charming medieval character. But because Ipswich was a 75-minute commute by rail from London, there was some concern about persuading employees to relocate and recruiting for future needs.

Foster and Associates was selected after 12 recom­mended firms had been reduced to a short list that included Ahrends Burton & Koraiek, Arup Associates, and Foster Associates. The determining factor in final selection seems to have been Norman Foster’s commit­ment to a strong personal involvement with the project. He was also known for his recent experience with open – plan offices.

Brief

The brief specified a minimum of 226,041 ft2 (21,000 m2) of floor space for a workforce of 1350 people using at least 1200 workstations. On the qualitative side, there were two primary criteria. First, given the need to draw and retain a workforce, the building and its work environment were seen as prospective attractions. Second, Foster responded

table 6.5 Normal Climate Data for Ipswich, UK

		Jan.	Feb.	Mar.	Apr.	May	June	July	Aug.	Sept.	Oct.	Nov.	Dec.	Year
	Degree-Days Heating	764	703	667	547	368	189	94	84	179	362	580	722	5319
Temperature	Degree-Days Cooling	0	0	0	0	0	8	28	30	5	1	0	0	46
Extreme High	59	59	63	75	79	88	91	88	82	73	64	61	91
Normal High	44	44	48	52	59	65	69	70	65	58	50	46	56
Normal Average	41	40	44	47	53	59	63	63	59	53	46	43	51
Normal Low	36	36	38	41	47	52	56	56	53	48	41	39	45
	Extreme Low	12	19	27	28	30	37	45	41	39	34	27	18	12
	Dew Point	33	32	35	37	44	49	53	52	49	45	39	36	42
Humidity	Max % RH	78	77	80	80	82	83	83	81	80	81	80	79	80
Min % RH	76	73	70	65	64	64	63	61	64	72	77	78	69
% Days with Rain	63	46	66	60	56	56	56	50	56	63	63	66	3
	Rain Inches	2.0	1.4	1.3	1.2	1.5	1.4	1.8	1.9	1.8	2.3	2.2	1.8	20.8
Sky	% Overcast Days	49	46	42	36	31	31	27	24	29	34	40	45	36
% Clear Days	3	9	21	8	9	3	0	3	11	4	0	14	9
Wind	Prevailing Direction	W	W	W	N	N	W	W	W	W	SW	W	W	W
Speed, Knots	12	11	11	7	6	8	8	7	8	8	9	10	9
Percent Calm	7	10	8	9	9	11	11	13	13	12	10	8	10
	Rain	19	14	20	18	17	17	17	15	17	19	19	20	12
Days Observed	Fog	19	18	19	19	19	18	19	21	18	21	20	21	232
Haze	13	14	17	17	19	16	20	20	18	17	15	15	201
Snow	5	5	3	2	0	#	0	0	0	0	1	2	18
Hail	0	0	0	#	0	#	0	0	0	0	0	0	#
Freezing Rain	#	#	0	0	0	0	0	0	0	0	0	#	#
	Blowing Sand	5	4	5	4	5	5	3	3	3	3	3	3	46

Figure 6.12 Climate analysis graphics.

to the project scope by proposing various means of work­station flexibility and relocatable furniture for the chang­ing office operations.

Site

Ipswich is perhaps the oldest town in England. It was set­tled by Stone Age peoples and developed as a river port by Anglo Saxons in the seventh century. Industry, shipbuild­ing, and status as a port in the Napoleonic wars fostered its growth through the eighteenth century. The advent of rail­road lines and a shipyard ensured growth and vitality into this century. Recently, Ipswich has been known as an engi­neering, commercial and insurance center.

Today Ipswich retains the flavor of a small market town. It is enlivened by its historical buildings, crowded pedestrian malls, and a soccer stadium with loud crowds on many evenings. The historical market area has more than 600 listed buildings, including 12 medieval churches.

A 1.7 acre (7,000 m2) site for the Willis Faber Dumas (WFD) building was eventually secured between the his­toric markets and the river port district. Commuters would walk about 10 minutes from the train station. The irregular plot of land is anchored on one side by a traffic circle and meets curving streets on all sides.

The historic character of the setting made for a sensi­tive context. To preserve the low-key scale, building authorities imposed a severe height limitation, and would allow vehicle access from only one side road. There was no room for on-site parking, but space in a nearby garage was secured. The garage was later converted to more insurance office space and features a new entry tower by Michael Hopkins.

Climate

Ipswich is located on the east coast of England, 82 miles (132 km) generally east and slightly north of central London. It is also about 57 miles (92 km) east of Cambridge, 52 miles (83 km) east of Stansted Airport, and 43 miles (69 km_ south of Norwich (see case studies 24,3, 11, and 23, respectively). A comparative look at the climate data for these neighboring locations reveals their similari­ty. All these locations share the same cool, cloudy, damp climate that Koppen described as Cfb (midlatitude, uni­form precipitation, warm summer). This is the same macroclimate classification that covers most of central Europe. It is also found in the United States in the region around Massachusetts, in New Zealand, in New South Wales, Australia, and other scattered locations.

The mesoclimate of Ipswich, taken at the level between Koppen’s macro-description of regional climates and the particular circumstances of microclimates at the site-specific scale, is moderated by its proximity to the maritime influence of the North Sea and by its geograph-

Dry-Bulb Temperature, °F Figure 6.13 Bin data distribution for Ipswich, United Kingdom. Concentric areas of graph indicate the number of hours per year that weather conditions normally occur in this climate. Similar to elevation readings on topographic maps, highest frequency occurrences of weath­er are at the center peaks of the graph. (Data sources: Engineering Weather Data, typical meteorological year (TMY) data from the National Climatic Data Center, and the ASHRAE Weather Data Viewer from the American Society of Heating, Refrigerating and Air-Conditioning Engineers.)

ical separation from the ocean air currents that pump moisture onto the western shores of the British Isles. Ipswich also lacks the crowded density of London and the resulting urban heat-island effects of the large city.

There is 33 percent less rainfall in Ipswich and Norwich than in London, even though all three climates have about the same number of days with rain. Both of the western coastal towns are not quite as cold as London in the winter, nor as warm in the summer.

The Woodbridge Royal Air Force weather station is located about 10 miles northeast of Norwich. According to bin data collected there, Norwich can normally be expect­ed to experience warm temperatures, exceeding 75°F for less than 1 percent of the year, comfortable conditions for 7 percent, cool temperatures ranging from 65°F to 55°F for 30 percent, cold temperatures below 55°F but above 35°F for 57 percent of annual hours, and frigid conditions below 35°F for 6 percent of the year.