Case Study: Capitol Tower

Project Goals
The Capitol Tower remodel project strived to increase the building’s tenant appeal. The project improved day lighting, health and safety, and energy efficiency. Reusing the existing structural frame minimized initial costs. Designing an efficient building envelope greatly reduced the size and cost of new mechanical equipment.

Project Name/Location	Rating	Completion Date	Cost/ft2 (excludes land)
Capitol Tower 206 E. 9th Street Austin, TX 78701	1-Star Green Building Rating	December 2008	not available

Project Description

Capitol Tower is a 150,000 square foot mixed-use building at 206 East 9th Street in the downtown Austin central business district. It houses business offices, a retail bank, structured parking, and a Catholic school. Completed in 2008, the extensive remodel project earned an Austin Energy Green Building (AEGB) 1-star rating.

The team overhauled an existing building, replacing its exterior skin, mechanical equipment, interior offices, restrooms, and lobby. Reusing the existing 20-story concrete structural frame limited deconstruction waste. The construction waste management plan helped avoid filling valuable landfill space. For example, the plan redirected existing cladding and finishes to recyclers.

The team replaced all windows with high performance glazing. This design strategy allowed them to use smaller, more efficient mechanical equipment with precise temperature and humidity controls. The new window systems allow more sunlight into the building without adding heat gain. They also provide enhanced acoustical characteristics, are aesthetically appealing, and provide daylight for each space.

Project Features

Team:

• Design team participated in charrette early in the design process
• Design team included sustainability features and Austin Energy Green Building requirements in pre-construction meeting
• Design team attended sustainability meetings

Site:

• Located in central business district
• Location provides access to public transit

Water:

• New fixtures reduced water use by 24%

Energy & Atmosphere:

• Day lighting, fluorescent and LED lighting in tenant spaces average 35% more efficient than required by energy code
• High performance chillers are part of a new energy management system with updated sensors and controls
• High performance glazing increases natural light without adding heat
• Small, efficient mechanical equipment achieves precise temperature and humidity control

Materials & Resources:

• Reused existing 20-story concrete structural frame
• Redirected hundreds of tons of construction waste to recyclers instead of the landfill
• Provided recycling carts to every tenant

Indoor Environmental Quality:

• New exterior glass and elastomeric paint help prevent interior moisture
• Low VOC paints, coatings, and adhesives. Some tenants used only no-VOC paint
• Dark and poorly ventilated parking garage now has natural ventilation

Innovations or Other:

• Highly reflective white membrane roof helps mitigate urban heat island effect
• Building standards in tenant leases assure use of green design strategies in future remodels

Testing/General Results:

Building commissioning began during construction to ensure the building’s HVAC, domestic hot water systems, renewable energy, and lighting/day lighting controls were properly installed. Commissioning also ensured systems operated in accordance with the engineer’s design documents, the owner’s project requirements, and the architect and engineer team’s basis of design.

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