TechPractices: Ocean Colony Landing, Component Structures, Marshfield, MA

TechPractices are outstanding housing projects throughout the U.S. where innovative technologies are implemented. Builders and remodelers can use these examples as models for projects of their own.

Summary

How does a developer of affordable homes with an environmental bent get a foot in the door of an affluent, conservative community, and maintain integrity? Component Structures, Inc. (CSI) uses innovative technology to address regulatory concerns and cost issues, creating an instant hit near the Boston waterfront.

Details

When designer William M. MacMullen served as Vice Chairman of the Marshfield Zoning Board of Appeals, he watched the board routinely turn down young families' proposals to add on to their homes. MacMullen would cast the only dissenting vote, as it was clear these families could not afford to buy the town's larger homes, and town zoning does not encourage affordable housing. For these families, there seemed no alternative.

Sensing a potential market as well as opportunity to alleviate the local housing crunch, MacMullen resigned from his post and partnered with Katherine Devine to form the non-profit Massachusetts Mutual Housing Association. Under this structure they were able to supercede local zoning for the chosen site and implement their design concept.

Located half a mile from the ocean, but with an airport and marshland between, the five-acre parcel cost the developer $800,000. With zoning allowing only one unit per acre, the land alone would add $160,000 to the price of each home. CSI could have built and sold high-end homes on this property. But with Marshfield's diversifying population, CSI realized the area needed more realistically-priced suburban housing. The resulting development, Ocean Colony Landing, is designed to be affordable and energy efficient, inspired by regional architecture, with minimal impact on the environment. About a dozen groups of three to five houses clustered together maximize open space, giving the dense community a more generous feel, and creating the aesthetic of a traditional New England village around a green.

After considering various structural systems, CSI decided that structural insulated panels (SIPs) have the flexibility to accommodate regional exterior styles without compromising economy or energy efficiency. Instead of the usual expanded polystyrene (EPS) insulation, these SIPs sandwich polyisocyanurate between the oriented strand board. Polyisocyanurate has a greater resistance to heat flow than EPS, allowing CSI to use 4½" thick panels to achieve R-30 walls, and 5½" panels for the R-38 SIP roof. The SIP company, Amos Winter Homes, offers a variety of house types, and CSI felt that a couple of their stock plans worked with minor modifications.

The high water table prohibited basements, spurring an alternate design for the foundation and heating system. Concrete slab with radiant floor heating was found to be most economical for this application. This required a 3' deep excavation under each house for an insulated area without ground contact under the slab. Without a basement, the heating system would have to be on the first floor. In the small houses, a compact system was needed. The plumber knew about a small package heating system that would provide domestic hot water as well as heating through a radiant floor -- Meisen's tankless hot water system is smaller than a 2-foot cube and fits in the homes' closets.

Installation/Construction

A May groundbreaking allowed all 50 homes to be occupied by September. Kathleen Devine of CSI attributes "construction speed 90% to the SIPs. The whole shell/frame is up in two to four days" for each cluster of houses. SIPs are used for both the walls and the roofs. All window and door openings are cut in the factory. While the panel company fabricates the SIPs, Component Structures prepares the site. CSI's modest construction crew could erect a whole cluster of three to five houses at one time, using a crane only to lift the roof panels. The lightweight, two-story walls are spliced together on the ground and tilted into place.

The site is heavily wooded with trees that enhance its value. An added benefit of the building systems approach, and SIPs in particular, is control of site mobilization. Instead of the lumber, sheathing, insulation, and various equipment taking over the site and requiring clearing of existing vegetation, building panels are stacked on the slabs, with roofs remotely pinpointed by crane to where they need to be, requiring only a clear path for the crane. As such, CSI was able to save many trees and incorporate them into the design.

Benefits/Costs

The SIPs keep the heat in the house with R-30 walls that fit together so tightly, air infiltration is almost negligible. With a radiant slab at the first floor, distribution for the second floor and loft is accomplished with gravity rise vents-inexpensive floor registers through the floor-since the heat is relatively confined within the envelope. Five years after construction, CSI audited the homes for energy use and found they average $445 to heat each season.

The SIP envelopes are quieter than conventional homes despite the developments' proximity to an airport-which might otherwise have prevented home development on the site. Thanks to SIPs, efficient site planning, and the modest size of the homes, costs could be controlled despite the sewer connection over a quarter mile away. Since SIP homes can be built faster than stick frame homes, the costs of carrying a construction loan are reduced. SIPs also produce minimal waste on site, reducing landfill tipping fees. A clustered site plan allows paving and service runs to be minimized, saving material and costs. At an average of $90,000, the condos cost approximately half that of the area median, and this includes amenities such as stained wood cathedral ceilings, well appointed kitchens, and overhead wood pergolas linking the buildings together.

Code/Regulatory

The first hurdle CSI faced was the community. In this well-to-do area, the developer needed a "comprehensive permit" to build the 50 units on only 5 acres. The local zoning board agreed to grant the permit for two reasons: (1) The existing community didn't already meet the state-mandated minimum of 10% affordable housing stock in the area; and (2) since the site was used as a dump for old building materials, CSI had it declared a "blight," further easing acquisition of the permit.

As a condition to developing the site, CSI had to provide service piping and a road from Ocean Colony Landing to the nearest water and sewer stub-ins and pay all fees. This was acceptable to CSI, who, for environmental reasons, was against septic systems for the development, which would have been expensive due to the high water table. It turns out the town benefited from the new sewer line as later houses could hook up for free, and be accessed by a new paved road.

The airport was considering a new runway where the community would be. In addition, the Federal Aviation Administration expressed its concern that kids might more easily access the airport grounds through the new, non-gated community. In response, Component Structures site-planned the development so that access to the airport would not be increased. Also, it was found that the best position for any new runway would be parallel to the proposed development, and not significantly closer than the existing runways. What about the noise? It turns out the sound level, though noticeable, is not intolerable. The tight SIP walls and roof contribute to the sound attenuation of the envelope.

Feedback

Devine says marketing was easy, with plenty of good press developing spontaneously. A groundbreaking ceremony featured representatives from the State Office of Community Development and other agencies. A developer of affordable housing is rare in these parts, and local newspapers soon caught the lead. The 50 condos sold in short order.

Would CSI do it again? They are, in fact, looking for sites to do a similar development within Boston proper, though aimed more toward the increasing middle-class need for housing. CSI is looking at SIPs for a repeat performance, though concerns for family privacy may vary the clustered arrangement of the houses. Although cedar shakes were appropriate for Ocean Colony's roofs, a more durable option may be sought for new developments.

Contact(s)

Do you have a specific question? Try the contacts listed below:

Component Structures, Inc.
49 Symphony Road
Boston, MA 02115
617-536-5186

Component Structures, Inc.
91 Old Colony Lane
Marshfield, MA 02050
781-837-6610
wmachq@aol.com

Amos Winter Homes
74 Glen Orne Drive
Brattleboro, VT 05301
802-254-3435
www.winterpanel.com