Prompt Two
Single-Family Home Densification
As housing demand continues to outpace supply, local governments across the US are embracing new policies to make it easier to add more housing units on single-family lots. Typically, these policy changes work in one or both of the following ways:
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Upzoning: “Upzoning” describes the rezoning of land to increase housing density. These changes can be made to an entire city or state at a time, but can also apply to specific areas based on, for example, proximity to transit. While upzoning can take the form of increases to allowable building height or reductions in minimum lot size, in this case, we’re thinking specifically about zoning changes that enable “plex” developments (duplex, triplex, or quadplexes) in areas previously zoned for single-family housing only.
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ADU allowance: Also known as “granny flats” or “in-law units,” Accessory Dwelling Units (ADUs) are residential units built on parcels of land already occupied by a primary residential unit. ADUs can be detached (built as a separate structure) or attached (built into the same structure as the primary residence).
Good to Know
As you think through your submission, bear in mind the importance of creating a clear path to implementation. Solutions may be envisioned as standalone business models, product development recommendations for an existing business or organization, or policy recommendations for a government agency. Other models may also work. As you weigh your options, be sure to consider how they impact the feasibility and scalability of your idea.
In addition to choosing a viable “vehicle” for your idea as detailed above, successful submissions usually focus on a specific geographic area and/or population. Housing solutions are rarely one-size-fits-all, and different areas and groups have their own distinct challenges and needs. Being specific about your target population and/or place will allow you to articulate to the judges how and why your solution is a fit.
In many cases, adopted policy changes allow for both detached and attached new units. New housing in any form helps to boost supply. While detached units may be a better fit in some situations, new attached units, which can be added by subdividing or expanding existing single-family homes, offer some significant benefits:
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Compared to new detached units, attached units require little or no additional land, and tend to be less expensive to implement.
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In addition to preserving valuable green space, attached units usually require less construction, meaning a smaller carbon footprint and less disruption to both the homeowner and neighbors.
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By adding into or onto an existing home, new units may be less likely to impact aesthetics or neighborhood character, making them less susceptible to community opposition.
Finally, a report from earlier this year shows that “empty nesters”, baby boomers who live in homes with one or two adults and no minor children, own 28% of the nation’s large homes. These underutilized homes present a significant opportunity.
Your Challenge
Your challenge is to create a solution that simplifies and encourages the addition of housing units within existing single-family homes. Remember, your focus should be on attached, internal, or subdivided units in existing single-family homes. Solutions could involve innovations in construction methods or materials that lower the cost of retrofitting homes, financial products or incentives that make densification more affordable and appealing to homeowners and developers, or new policies and regulatory reforms that streamline the approval process for these modifications. Additionally, design solutions that overcome challenges faced by residents—such as privacy concerns or space limitations—are critical. Regardless of the approach, your solution should ultimately aim to improve housing affordability by increasing the supply of units within existing single-family neighborhoods.