Courtesy : www.researchgate.net

Green affordable housing design

Residences in the U.S. are responsible for $160 billion worth of energy consumption for heating,

cooling and lighting each year, totaling 20% of total U.S. energy consumption

]. Additionally, there is

a critical shortage in affordable housing, especially among the most populous U.S. cities, as housing

demand outpaces supply, leading to rising prices. The notion that green homes can be a solution

to the energy, emissions and affordability issues is an attempt to tackle multiple problems with one

solution, but becomes difficult when quality, durability and sustainability targets must be met while

being affordable for homeowners

]. A home is said to be affordable when no more than 30% of a

household’s annual income is spent on housing

], but this often sets the budget too low to afford

energy-efficient upgrades and technologies, like photovoltaics (PV). With the Environmental Protection

Agency (EPA) encouraging local governments to promote energy efficiency in their jurisdictions

through improvements in residential units

], it may be possible to bring new energy-efficient

residences closer to the 30% affordability mark using strategies like considering energy efficiency at the

beginning of the design process rather than as an “alternate add” to be value-engineered later. This can

be done to generate triple-bottom-line (TBL) benefits for the local community. However, we argue that

the TBL is not enough because it ignores subjective criteria that are essential for the success of any type

of project, but perhaps more so for projects for those living below the poverty line whose experience

Designs 2018,2, 26 2 of 13

of homes are not personally restorative nor necessarily sources of personal and community pride.

Subjective characteristics (feelings of safety, beauty, color, views, etc.), however, increase the sense

of place, investment and architectural character and lead to places and communities that thrive as

they are sustained as people are more likely to care for and invest in them. Instead of a TBL approach,

we argue for an approach based on Integral Sustainable Design and test its ability to provide integral,

sustainable and affordable projects.

Affordable energy-efficient houses have many benefits, such as reducing greenhouse gas

emissions, decreasing pollution, improving air quality and thermal comfort, and conserving resources.

Reduced energy costs are added benefits to ensure affordable housing budget targets are met.

According to the EPA, an Energy Star home can reduce its energy use up to 30% or $600 per year on

average

]. However, as mentioned above, there are additional experiential and social benefits that

are often not achieved in other affordable projects that pursue the TBL. To actualize these economic,

environmental and social benefits, major cities need a new holistic prototypical integral sustainable

home design to promote affordable energy-efficient housing in low-inco me neighborhoods. This study

proposes and tests the new approach to affordable and energy-efficient design for a low-income

rowhouse in Philadelphia, which has the highest poverty rates among the 10 largest cities in the

U.S.

] (see Figure 1). The design aims to be replicated as an investment in the future where people

live in a sustainable and efficient home with net zero energy and zero emissions. The value proposition

for this home is more than energy efficiency and a small payback period, but rather the technological,

energy and social resilience the project aims to add to a typical affordable home by providing choice

and redundancy: how to spend money in the community to further one’s values using funds saved

from installing technology; to remain with power while others are blacked out due to storms; and the

back-up provided by the ability to purchase electricity from the grid in the event the onsite generation

does not provide enough. The methodology includes the proposed low-income green housing design

in Philadelphia accompanied by guiding principles and green goals. The research approach consists

of design development with certain restrictions in terms of location, use, sustainability goals and

cost. Then, the proposed design is analyzed and compared to a baseline case. In each step of the

comparison, the proposed design is improved to make it more sustainable, especially in terms of

energy use. Life-cycle assessment (LCA) and cost analysis were performed in the proposed model to

evaluate building assemblies, as well as affordability of this design in the low-income neighborhood.

The scope of this study is limited to high-performance residential design in terms of energy efficiency

and affordability.



Figure 1. Poverty rates in the U.S. Adapted from [6], Cured Philadelphia, 2017.

Designs 2018,2, 26 3 of 13

2. Background

Affordable energy-efficient houses are where green-building benefits and affordable housing

goals intersect in the literature. Though ‘green’ is not directly understood by many home owners,

long-term durability, a healthier living environment, and reduced energy costs make green houses

attractive

]. According to a survey by Building Design and Construction White Paper, 82% of home

seekers value energy

The benefits of green housing were apparent for low-income residents, as energy-efficient products

and properly insulated homes decrease utility costs

]. There is an additional positive impact of green

housing for especially low-income and minority residents, who live in neighborhoods with higher

rates of asthma and environmental health hazards [

]. That is, improved health and occupant comfort

benefits, which provide cleaner air and decrease asthma and similar conditions [11].

Concerns related to green housing were mentioned as having higher first costs compared to

conventional affordable housing. It was also mentioned that higher initial capital costs can demotivate

developers to invest in green construction, as green rating systems, as well as house seekers, look

for low initial investments [

]. This explains the shortage of affordable housing especially in

metropolitan cities like Philadelphia. This study and the proposed design is created to address

this critical shortage of affordable housing in cities, while focusing on the emerging recognition of their

impact on healthy communities.

3. The Proposed Low-Income Housing Design

This research proposes creating a residence using the formal precedent of a rowhouse to

integrate with the site context and the existing and historic residential architecture of Philadelphia.

The site (Figure 2) was selected in the North Kensington neighborhood, since it is among the poorest

neighborhoods where 68.6% of the population lives below the poverty line [

]. A design imperative

for the project is to create an integral sustainable design, and so the project was driven by an adaptation

of DeKay’s Integral Sustainable Design Framework [

]. To start the design process, guiding principles

were created using four quadrants to establish a direction and focus for design decisions enabling the

most integral, holistic design results (see Table 1). Considering the location, the main goals are as given