By Bob Tiscareno, AIA, and Scott Glazebrook, AIA
With the housing affordability and availability crunch reaching many corners of the country, higher-density multi-family architecture developments are increasingly more commonplace. Moreover, as metro areas themselves become denser in response to population growth, the range of buildable sites often narrows to compact infill lots that can be challenging for maximizing dwelling unit count, access, and parking. Multi-family projects must also be viewed as highly “livable” by tenants to retain maximum occupancy, yet stay within a sensible budget to keep rents reasonable and ensure viability.
It takes a great deal of thought, and often a large dose of creativity, to maximize livability and unit count in multi-family architecture while also staying within budget; especially on challenging sites. The most common factors that architects can help you influence directly fall into three categories: maximizing unit count, designing for context and comfort, and designing around challenging structural constraints.
Innovation in Maximizing Unit Count
High-density multi-family housing projects are, in essence, geometric puzzles with the developer’s goal of achieving the yield potential without compromising livability. Every multi-family development is constrained by variables such as zoning and building code regulations, competitive amenity needs, and context. Making sure that a building’s layout is efficient, with appropriately stacked units, can have a huge savings on costs. “Efficient” here means there isn't too much corridor space or un-programmed common areas that are not part of the rentable square foot total aggregate.
In general, we’ve found that we can attain at least 10% more units by looking for opportunities to vary the unit layouts in a way that allows for an overall tighter-fitting layout, such as utilizing nested unit-types, and extending building envelope through appropriate modulation.
With Mill Creek Residential’s Modera Redmond for example, we ultimately fit in 300 apartments by strategically deploying nested units along the long side elevations and modulating the façade to increase the building envelope allowing for windows to “open-up” smaller homes to sunlight and views. We maximized the building envelope by also creating a kind of “big wood block”—carving out meaningful sunlit courtyards into the interior and orienting the units for the tightest fit. We were very selective about each apartment’s location and layout, to optimize the space usage, and access to natural light to create the most livable homes possible.
Limiting the number of unique unit types can greatly reduce construction costs. For Modera Redmond, we established an optimum depth-to-width ratio for each unit type, then strategically distributed them into the building’s wings to meet zoning requirements and the required setbacks.
This multi-family project’s location also presented unique zoning challenges with only single-street frontage but deep lot and fire department access requirements, and constructability limits on subterranean construction depths due to high groundwater. Design decisions to achieve the desired density (as well as design review board approval) included a highly modulated, “accordion style” street-side façade that is not usually seen in semi-urban mid-rise apartment communities. This reduced the apparent façade length and gave a shallower setback, which maximized the workable site area.
Designing Multi-family Architecture for Comfort and Context
Highly livable multifamily projects are rich in desirable amenities, daylight, walkability, and sense of place. The units themselves must be ideally sized, spacious, and full of natural light and appealing features. In terms of just putting that all on the site, you want to look at having a good location for the lobby, making sure that the visibility, access, and circulation around and within the project makes sense and is convenient.
A good example of livability is Vibrant Cities’ The Cove, a 60-unit mixed-use development in Seattle. Here we integrated retail into the lobby and common areas by building an interior mezzanine lounge whose design echoes the neighborhood’s other retail spaces. Two micro-retail shops are accessible from the lobby and sidewalk, alongside a 3,000-square-foot double-height corner restaurant. The compact design also has room for lifestyle amenities and community areas such as a rooftop deck with fire pit and plantings, fitness room, storage lockers, and package delivery room.
High-density multi-family projects that sit on smaller, infill sites demand a strong contextual integration with their neighborhoods. Designing a seven-story apartment building next to single-family homes, for example, means smoothly transitioning to the less dense areas. The Cove had to blend in with historic single-family homes, so we spent extra care to manage the building’s scale. We also added extra visual layers to the façade to create a relationship to these 19th-century residences.
Designing Around Structural Constraints
Intelligent space planning is often constrained by structural considerations such as the placement of support columns, elevator shafts, HVAC systems, and loading access. This was especially the case for The Danforth, a 265-unit, 16-story luxury mixed-use apartment building at the confluence of three popular Seattle neighborhoods.
Besides the careful site planning required to accommodate the small, odd-shaped, hillside footprint, the project’s street-level Whole Foods needed 40,000 square feet of retail space over two floors, and 12,000 square feet for loading services. Typical structural engineering could have placed columns in the middle of garage throughways, grocery aisles, and living spaces.
The final design creatively worked to meet structural requirements while retaining the necessary open spaces. It maximized column spans, included exposed concrete
supports as part of the design aesthetic where appropriate, and incorporated several short, strategically placed shear walls for open spaces. It also doubled up on space usage by integrating a shared loading dock with the tower, two freight elevators, three passenger elevators, and a grand interior staircase for Whole Foods.
Adding It All Up
Thoughtfully balancing unit count with livability, and site and building constraints, not only maximizes revenue and lease duration, but can also help control construction costs leading to more affordable housing. Ultimately, with the right combination of design creativity, problem solving, and approaches to assuring livability, your architect can help you meet all your high-density multi-family housing project goals.
Questions? Email Scott Glazebrook at scottg@tiscareno.net