Morgan Hill Indoor Recreation Center

  When the City of Morgan Hill, California was ready to design and construct a 50,000-square-foot (4,645 square meter) recreational and community center on a site adjacent to the city’s largest park, there was a long list of requirements. The city’s goals included aiming for the U.S. Green Building Council LEED Silver certification standard, as well as PG & E’s (the local utility company) rebate program for exceeding California’s Title 24 energy requirements. The project also needed to maximize views of picturesque El Toro Mountain—the symbol of Morgan Hill.

After careful consideration of the city’s wish list, Janet Tam of Noll & Tam Architects says, “we chose concrete masonry units (CMU) for the Centennial Recreation Center for these practical reasons: durability; water resistance; close appearance to natural stone at reasonable cost; and it provided a good alternative to stucco finish (client requirement).”

But during the design process, Tam says, they also “realized the creative potential of CMU. We enjoyed shaping the building with the blocks.” The design was primarily composed of high strength masonry block walls supported by heavily reinforced pilasters. A rhythmic ribbed design was created by selecting different individual block sizes and depths. The appearance of the block was selected to contrast against glass. The CMU pairs extremely well with the building’s main feature—a dramatic curtain wall that captures views of the mountain and invites viewers to observe the activity indoors.

Working closely with our engineers we pushed the conventional design of CMU construction in order to create large, tall volumes and sculptural forms. During construction these walls were impressively braced against wind and earthquake forces until the roof was completed. For the most dramatic space inside the building—the natatorium—we designed a vaulted wing that springs forward. It was challenging to construct the 20-foot (6.1-meter) high vaulted walls, requiring the cutting and shaping of each block at the top of the wall to form a gentle curve.

Concrete masonry was also selected for its excellent thermal properties. The ability to additionally insulate the blocks created a more efficient building envelope. The design utilizes heat gain in the winter months to passively warm the space, providing considerable life time cost savings for the community. Optimum daylighting was achieved by orienting the building north-south. Additional sustainable design solutions include the use of recycled content building products and CMU.

The selection of the CMU color was essential to the look and feel of the new building. The earth tone of the block is reminiscent of historic adobe construction, and it complements the natural landscape. Complementary and contrasting colors were selected to augment the textural patterns and building forms; pilasters have a contrasting color to the walls in between. The block colors became the reference point for the entire project: all the other building elements such as window sash, metal roofing, and interior materials depended on the strength and warmth of the CMU earth tones.

The designers particularly liked experimenting with the different CMU surface treatments to develop the design vocabulary. To create character in the surface of a wall at eyelevel, a split face finish was selected that also provided a texture similar to stone. Higher up on the wall a precision finish was used for contrast as well as economy. On the interior, a ground face finish was specified that was elegant and smooth to the touch.

The facility provides many indoor-outdoor connections: shaded outdoor patios, an entry courtyard and garden that accommodate community events, and a terrace extension with a grass berm. Since the Recreational Center is adjacent to Morgan Hill’s largest city park, the site was planned to coordinate with other park improvements such as creek naturalization and a skate park, and created access links to bicycle and walking trails.


Centennial Recreation Center, Morgan Hill, CA

Noll & Tam Architects, Berkeley, CA

Asociate Architect
Ratcliff, Emeryville, CA

Structural Engineer
Forell/Elsesser Engineers, Inc., San Francisco, CA

General Contractor
West Coast Contractors, Fairfield, CA

Masonry Contractor
The Henson Company, Seattle, WA

Block Producers
Basalite Concrete Products, North Highlands, CA

Blocklite, Selma, CA
























 Concrete Masonry Thermal Performance

Concrete masonry’s thermal performance depends on its steady-state thermal characteristics (described by R-value or U-factor) as well as the thermal mass (heat capacity) characteristics of the assembly. The steady state and mass performance are influenced by the size and type of masonry unit, type and location of insulation; finish materials, density of masonry, climate, and building orientation and exposure conditions.

Thermal mass describes the ability of materials to store heat. Because of its comparatively high density and specific heat, masonry provides very effective thermal storage.Masonry walls remain warm or cool long after the heat or air-conditioning has shut off. This, in turn, effectively reduces heating and cooling loads, moderates indoor temperature swings, and shifts heating and cooling loads to off-peak hours. Due to the significant benefits of concrete masonry’s inherent thermal mass, concrete masonry buildings can provide similar energy performance to more heavily insulated frame buildings.

The benefits of thermal mass have been incorporated into energy code requirements as well as sophisticated computer models. Energy codes and standards such as the International Energy Conservation Code (IECC) and Energy Efficient Standard for Buildings Except Low-Rise Residential Buildings, ASHRAE/IESNA Standard 90.1 permit concrete masonry assemblies to have less insulation than frame systems to meet the energy requirements, due to their thermal mass.

There are many options available for insulating concrete masonry construction. The NCMA publication, Thermal Catalog of Concrete Masonry Assemblies, presents tabulated R-values of common concrete masonry constructions. Because of concrete masonry’s inherent design flexibility, the assemblies presented are not all-inclusive, but are intended to represent a wide range of common concrete masonry wall designs.

Each page of the Catalog addresses a particular assembly and includes brief notes on the features of that construction and a Table of R-values for 6-in., 8-in., 10-in. and 12-in. (152 mm, 203 mm, 254 mm, and 305 mm) concrete masonry units of various concrete densities and with various types and amounts of insulation. Tabulated R-values include ungrouted walls, lightly reinforced walls, heavily reinforced walls and fully grouted walls. Other reinforcement schedules can be calculated using the information in TEK 6-2B, R-Values and U-Factors of Single Wythe Concrete Masonry Walls.

Thermal Catalog of Concrete Masonry Assemblies is available on the NCMA website ( for electronic download or hardcopy purchase and TEK 6-2B and other related TEK are available free on NCMA member web sites. Go to for links. CMD