CEDC, a term coined by Walsh Construction Company, is a disciplined approach to affordable housing design and construction. CEDC applies cost-efficiency principles to the overall design of a building and its sub-systems. It utilizes standardization, repetition, and prefabrication, pulling from the ideas of economies of scale and lean construction methods whenever possible. CEDC is not used to create the lowest-cost projects but is used to add as much value as possible by focusing the budget on necessary components.
General Budget Breakdown
Think of budget in terms of value, not cost. Ask yourself, “What is the maximum amount of value that we can add with the given budget?”
CEDC has a goal of a 20% reduction in hard construction costs. These savings create room for the client to include wish-list items or extra amenities that add value to the residents.
If we can reduce 20% of construction costs, there is room in the budget to add value. Here is how we suggest using the remaining 20% of the budget:
- 5% for performance
- 5% for joy (amenities and community spaces)
- 10% cost reduction
Pushing costs back saves money and makes better buildings. Successfully implementing CEDC methods will produce more homes, and those homes will offer more value to the community.
So how do we do it?
Core ideas:
- Seek out unencumbered sites
- Standardize and repeat elements
- Keep it simple – take a logical approach to execute the design
We don’t have to spend time and money reinventing the wheel for each project. If we standardize 80% of the design, then we can customize the remaining 20% to be unique and meet the client’s desires. We concentrate on standardizing the project’s inner core elements while still allowing for customization at the outer shell elements.
Case Study
BURI BLDG:
An affordable apartment building designed by MWA and constructed by Walsh, The Buri Building proves that CEDC can provide elevated design, meet design review requirements, and cut construction costs. A trustworthy example, the Buri Building had the 2nd lowest cost per unit of the 55 publicly subsidized affordable housing projects constructed in the Portland metro area over the past five years.
Seek Unencumbered Sites
Not following the recommendation of starting with an unencumbered site, the Buri Building’s site was, unfortunately, the opposite. Due to its location on a long, narrow property along city-owned streets, the site had an abundance of zoning requirements that steered our decisions. This proves that the CEDC approach can be practical even when the optimal conditions are not available.
Standardize and Repeat Elements
Using the 80% standardization, 20% customization rule, the Buri Building is a design-forward project that provides residents with generous amenities.
Standardization was the key cost-saving aspect of this project. The Buri Building consists of 159 apartments, and we were able to optimize the building so that it only required ten different unit types. Except for the ADA units, each unit type incorporated the same bathroom and kitchen layout.
This repetition leads to efficiencies in the cabinetry and bath products and the mechanical and electrical design. It provides design efficiencies throughout the documents, cost efficiencies through streamlining the fabrication and buying of materials, and a greater degree of construction quality control.
Due to the savings from standardization, the Buri Building was able to come to life through customization. Large courtyards, community rooms, and an elevated façade set a high standard for cost-effective, affordable housing. Amenities were optimized using 5% of the cost savings allocated for joy. The 5% savings allocated for performance helped the Buri Building pursue Earth Advantage Platinum Certification.
Keep it Simple
This project taught us that “keeping it simple” is still a lot of work. We had to be highly detail-oriented and carry out maximum quality control to ensure that we didn’t produce waste. However, minimizing waste of time and materials indeed paid off in the value added to the project.
Working on affordable housing projects brings an extra layer of pressure and uncertainty in terms of budget. Choosing to pursue Cost-Efficient Design and Construction methods early in the process and creating space in the budget for improved performance and unknown risks will help mitigate that uncertainty.
Photo Credit: Thomas Harris and David Papazian