The 2020 This Old House Idea House, known as the Cottage on the Cape, represents a bold rethinking of coastal home design. Located in Eastham, Massachusetts, this project was born from a design contest challenging architects to create affordable, energy-efficient housing for year-round families and young professionals facing steep real estate prices on Cape Cod. The result is a home that balances traditional coastal aesthetics with cutting-edge building science. This kind of innovative housing model echoes other forward-thinking residential concepts, such as the Gilbanes Welcome Home 2025 Blueprint For Transforming University Campus Student Housing, where affordability and intelligent design converge to serve underserved markets.
The Design Contest That Changed the Conversation
The Cottage on the Cape began not as a developer-driven project but as a creative challenge. The Cape Cod Young Professionals House Design Contest invited architects to produce plans that would help year-round families gain a foothold in a market where the median home price often exceeds half a million dollars. Union Studio Architects submitted the winning design, and their vision was as practical as it was inspired.
The brief demanded more than just an attractive facade. Contest entries had to address three core challenges facing Cape Cod residents:
- High land and construction costs that push young buyers out of the market
- The need for energy efficiency to keep long-term utility expenses manageable
- The desire for flexible spaces that can generate income or accommodate multi-generational living
Union Studio Architects answered with a home that feels both timeless and thoroughly modern. The design draws from classic Cape Cod cottage forms but reinterprets them with open floor plans, abundant natural light, and a layout that maximizes every square foot. Creating a warm welcome to any property starts with thoughtful entry points and landscaping, as discussed in Five Bright Ideas For Creating A Warm Welcome, and this home delivers on that promise from the moment you approach the front door.
A Super-Tight Building Envelope for Year-Round Comfort
One of the standout features of the Cottage on the Cape is its high-performance building envelope. The design prioritizes thermal efficiency to an extent rarely seen in single-family residential construction. This approach is reminiscent of the principles explored in the Modern Barnhouse Vision Colin Oglesbay And The 2021 This Old House Idea House, where energy performance and material selection drive the design process.
The construction team used several strategies to create a super-tight, super-insulated building envelope:
- Insulation-backed structural sheathing. The exterior walls use ZIP System sheathing with a built-in insulation layer. This provides a continuous thermal break between the exterior sheathing and the wall framing, eliminating thermal bridging that typically leaks heat through the studs.
- Long-span engineered floor joists. Twenty-foot TJI floor joists by Weyerhaeuser span the full width of the house. These lightweight engineered joists create a strong, squeak-free floor system while reducing the need for interior load-bearing walls.
- LVL ridge beam. A 36-foot Microllam LVL beam by Weyerhaeuser runs the length of the roofline. Engineered from laminated veneer lumber impregnated with resin, this beam resists moisture and mold during construction and supports the rafters so ceiling joists are not needed, creating a cleaner ceiling profile.
- High-performance subflooring. AdvanTech subfloor panels provide superior moisture resistance and dimensional stability compared to traditional plywood.
The Financial Innovation: Income-Generating Spaces
Perhaps the most forward-thinking aspect of the Cottage on the Cape is its inclusion of two income-generating spaces. The home features a separate rental apartment, often referred to as an accessory dwelling unit (ADU), and a dedicated maker’s workspace. These spaces are designed to help the homeowner offset the mortgage while building equity.
The rental apartment occupies a distinct portion of the house with its own entrance, living quarters, kitchenette, and bathroom. It can be rented to seasonal visitors, traveling nurses, or long-term tenants. The maker’s workspace provides a separate area for running a small business, studio practice, or workshop. This dual-income strategy addresses one of the biggest hurdles to homeownership on Cape Cod: the gap between income and purchase price.
From a financial planning perspective, the ADU alone can generate enough rental income to cover a significant portion of the monthly mortgage payment. In a resort market like Cape Cod, where summer rentals command premium rates, a well-designed one-bedroom apartment can bring in $1,500 to $2,500 per month during peak season. The maker’s workspace adds another revenue stream or, alternatively, provides a dedicated area for the homeowner to run their own business, reducing commuting costs and offering tax advantages for home office use.
The two spaces also offer lifestyle flexibility. The ADU can serve as guest quarters for extended family visits, a caregiver’s suite for aging parents, or a crash pad for adult children returning home between jobs. The maker’s workspace can transition into a home gym, an art studio, or additional storage as family needs evolve over time. This adaptability means the home can serve a single young professional, a growing family, and eventually empty-nesters without requiring major renovations. The zoning on the Cape Cod lot was carefully reviewed to ensure both uses complied with local regulations, a step that any homeowner replicating this model should take seriously before breaking ground.
The thoughtful placement of windows throughout these spaces was critical for both privacy and natural light. The approach taken here shares insights with the Window Selection For The Farmhouse In Fairfield County Marvin Windows In The This Old House Idea House, where careful window placement balances views, ventilation, and energy performance.
Here is a breakdown of how the two income spaces compare:
| Feature | Rental Apartment (ADU) | Maker’s Workspace |
|---|---|---|
| Primary use | Short or long-term tenant housing | Small business or craft operations |
| Separate entrance | Yes | Yes |
| Plumbing | Full kitchenette and bathroom | Minimal (sink) |
| Income potential | Higher (seasonal or annual rental) | Variable (business dependent) |
| Zoning considerations | ADU regulations apply | Home occupation permits needed |
| Construction complexity | Higher (full living space build-out) | Moderate (finished shell with utilities) |
Key Materials and Systems at a Glance
The builder, Cape Associates Inc., selected materials that would stand up to the coastal Cape Cod climate while meeting the project’s energy goals. The table below summarizes the major material choices and their specific roles in the home’s performance.
| Material or System | Manufacturer | Purpose in the Build |
|---|---|---|
| TJI Floor Joists | Weyerhaeuser | Long-span, squeak-free floor structure |
| ZIP System Sheathing | Huber | Continuous thermal break and air barrier |
| Microllam LVL Beam | Weyerhaeuser | 36-foot ridge beam, eliminates ceiling joists |
| AdvanTech Subfloor | Huber | Moisture-resistant subflooring |
| PermEntry Basement Stairwell | BILCO Company | Precast concrete entry to basement |
| Engineered Lumber | Weyerhaeuser | Framing and structural support |
| Windows and Doors | Marvin | Energy-efficient fenestration |
Each product was chosen not only for its individual performance characteristics but also for how it integrates with the rest of the building system. For example, the zip system sheathing works with the engineered joists and LVL beam to create a structurally continuous, thermally efficient shell.
Construction Insights and Lessons Learned
Ground broke in early December, with the foundation pour happening during the Cape Cod winter. The construction sequence followed a methodical progression that offers lessons for anyone building in cold climates or tight schedules.
Key construction steps in order:
- Foundation pour. The concrete foundation went in during early winter on a wooded lot in Eastham. A precast concrete stairwell from BILCO was installed simultaneously, ready for backfill and a bulkhead door.
- Floor system installation. Twenty-foot engineered floor joists were set across the full width of the house, creating a stable platform for the framing above.
- Offsite wall framing. Exterior walls were framed and sheathed offsite, then delivered to the jobsite for rapid installation. This approach reduces weather exposure and speeds up the build.
- Ridge beam placement. A boom truck lifted the 36-foot LVL ridge beam into position, a critical structural moment that defined the roofline.
- Window and door installation. Crew members studied the plans carefully before installing windows and doors, ensuring proper sequencing and weather sealing.
The aerial view of the home midway through construction shows the second floor deck in place while revealing the ADU, side entry, and garage maker space below. This birds-eye perspective highlights how the building massing breaks down what could be a large structure into a series of smaller, cottage-like forms that fit the neighborhood context.
Why the Cottage on the Cape Matters
The 2020 Cottage on the Cape Idea House is more than a showcase of products and techniques. It is a proof of concept for a different kind of residential development: one where affordability, energy efficiency, and income generation are baked into the design from day one. The home demonstrates that attractive design and responsible construction do not have to be mutually exclusive, and that thoughtful architecture can address real economic pressures facing communities across the country.
For builders, architects, and homeowners alike, this project offers a replicable model. The combination of an ADU and a maker’s workspace could be adapted to almost any lot with proper zoning, turning a single-family home into a small-scale economic engine. The super-insulated envelope reduces long-term operating costs, making the home more affordable over the life of the mortgage. And the design itself proves that a house can be both cost-conscious and beautiful, rooted in regional tradition while embracing modern building science. This idea house is part of a larger tradition of showcase homes that push the industry forward, as explored in Inside The This Old House Idea House How Showcase Homes Inspire Real World Design.