Our industry is engaged in an important dialogue to improve the efficiency and resilience of real assets through transparency and industry collaboration. This article is a contribution to this larger conversation and does not necessarily reflect GRESB’s position.
Sustainable affordable housing is about keeping homes efficient, healthy, and resilient without pricing people out. And it’s not just about design and construction. It’s about practical outcomes: lower utility waste, fewer comfort complaints, and buildings that keep performing after move-in.
Key takeaways
- Energy waste hits harder when residents can’t absorb surprise utility costs
- Design helps, but day-to-day operations decide what residents actually experience
- High-performance social housing exists at scale, and it’s worth learning from
- In the U.S., LIHTC and state QAPs shape what gets built and what gets prioritized
- Benchmarking and routine tuning help prevent performance from slipping over time
When sustainability feels like a luxury, it’s easy to miss the point
When people picture an efficient, healthy building, they often picture a glass office tower. Or a high-end apartment with rooftop solar. But some of the strongest arguments for sustainability show up in a different place: affordable housing.
Because the people who live there often feel the building the most. Drafty walls show up as utility bills that don’t fit the month’s budget. Poor ventilation shows up as asthma, allergies, and missed work or school. Heat waves and flooding hit harder in older buildings that haven’t been maintained the way they should be.
For these residents, efficient and healthy housing isn’t a perk. It’s stability.
What other countries can teach us
Vienna: social housing at scale
Vienna is often cited because a large share of residents live in municipally owned or publicly supported housing. Depending on how it’s defined, sources commonly cite about half to around 60% of residents.
That scale gives the city leverage. It can bake long-term quality expectations into how housing gets funded and delivered, including energy performance and livability.
Seestadt Aspern: building a new district with high-performance homes
Seestadt Aspern is one of Europe’s largest urban development projects. It includes multiple social and cooperative housing projects built to very high energy standards, including passive house-level approaches in some developments.
Many projects also connect to low-carbon heat systems, such as district heating (sometimes paired with heat pumps), and the district is planned around transit and walkability.
Norwich: Goldsmith Street proves “affordable” can also mean “ultra-efficient”
Goldsmith Street in Norwich is a council housing development designed to Passivhaus standards. It includes 105 homes and won the RIBA Stirling Prize in 2019, the first social housing project to do so.
Many reports cite estimated energy costs around 70% lower than average, driven by low heating demand by design.
The Netherlands: Energiesprong tackles the “it worked on paper” problem
Energiesprong focuses on deep retrofits, often using prefabricated exterior panels and roof systems to cut disruption and speed installation. Many summaries describe installs in about a week to 10 days, depending on the building and scope.
Accountability after handover is prioritized. Energiesprong projects commonly include a long-term performance guarantee, often described as 30 years, and some programs tie underperformance to financial penalties.
That’s the point. Performance doesn’t end on opening day.
The lesson: this is where sustainability pays off fastest
Affordable housing isn’t where sustainability ambitions should drop. It’s where the benefits land most directly for residents, owners, and public dollars.
On the investment side, benchmarking affordable housing impacts is catching up. In 2025, GRESB introduced a Residential Component designed to provide more tailored insights for residential portfolios, including considerations such as housing affordability, community safety, and access to infrastructure and amenities.
In the U.S., LIHTC is the main engine, and QAPs set the rules
In the U.S., the primary tool for producing affordable rental housing is the Low Income Housing Tax Credit (LIHTC). It supports development by awarding tax credits that are typically sold to investors for upfront equity, in exchange for long-term income and rent restrictions.
States allocate credits through a Qualified Allocation Plan (QAP), which lays out priorities and scoring for awarding credits. More and more QAPs also award points for sustainability features and green building standards.
That helps. But design-stage recognition can only take you so far. Buildings change. Settings get overridden. New teams inherit systems they didn’t commission.
That’s why operations matter. Every day.
“A building can be designed beautifully and still drift a few years in if no one is watching the data,” says Karen M. Esparza, ARM®, NPCC, HCCP, SHCM, Senior Vice President, Asset Management for BLDG Partners, a real estate investment firm focused on infill development and the preservation of workforce and affordable housing. “In affordable housing, that drift tends to show up first as higher utility bills residents struggle with. The systems that protect against those surprises are operational systems. They belong in the management plan, not just the architect’s spec book.”
What “operational sustainability” looks like in real life
If you manage affordable housing, you already know the playbook. It’s the unglamorous work that keeps residents comfortable and costs predictable.
- Benchmark energy and water. Then use the data
- Keep equipment tuned and schedules realistic
- Watch ventilation and moisture. Comfort complaints are data, too
- Share simple actions residents can actually use, without shifting the burden onto them
This is the work that makes ‘efficient’ stick.
Where IREM® fits
About 30% of IREM members with the Certified Property Manager (CPM®) certification and about 30% with the Accredited Residential Manager (ARM®) certification include affordable housing units in their portfolios. Leaning on this expertise, IREM is developing a version of the IREM Certified Sustainable Property (CSP) certification tailored for LIHTC developments, with the goal of having it recognized in state QAPs as an approved green building option alongside existing programs.
More than 3,000 properties already hold the CSP. The certification focuses on what ultimately drives performance over time: benchmarking and target-setting, energy and water management, indoor air quality, waste, day-to-day operating practices, and targeted improvements. Properties recertify every three years to ensure those practices stay in place.
What’s new for LIHTC is a two-phase structure. One set of requirements applies during development, and another carries forward into ongoing operations. Most certifications recognized by QAPs today focus on design and construction. The CSP extends accountability into the management phase, where long-term outcomes are actually determined.
In that way, the CSP addresses the same post-handover performance gap that programs like Energiesprong target through contractor guarantees. The difference is approach. CSP does it through a framework of best practices, targets, and strategies for continuous improvement.
To date, IREM has engaged with state housing financing agencies and convened a work group of LIHTC experts, representing different perspectives on the QAP process.
Bottom line
Once the financing closes and the building is occupied, the people inside deserve a home that:
- doesn’t cost too much to heat or cool
- supports health and comfort
- can handle a hotter, wetter, more volatile climate
That’s baseline housing. Not luxury housing.
Sources
- Vienna social housing overview (City of Vienna / Socialhousing Wien): https://socialhousing.wien/policy/the-vienna-model
- Vienna share cited in mainstream summary (ABC News, 2023): https://www.abc.net.au/news/2023-08-04/vienna-s-social-housing-and-low-rent-strategy/102639674
- Goldsmith Street background + Passivhaus / Stirling Prize coverage (e-architect): https://www.e-architect.com/england/goldsmith-street-housing-in-norwich
- Goldsmith Street energy-cost estimate discussion (Architizer): https://architizer.com/blog/inspiration/stories/goldsmith-street-stirling-prize/
- Energiesprong principles: https://en.wikipedia.org/wiki/Energiesprong
- Energiesprong 30-year warranty / financial penalty example (CIBSE Journal): https://www.cibsejournal.com/case-studies/a-forward-leap-how-dutch-housing-process-energiesprong-guarantees-performance/
- GRESB Residential Component (GRESB, 2025): https://www.gresb.com/sustainable-leadership-in-residential-real-estate/
- LIHTC overview (Congressional Research Service, updated July 11, 2025): https://www.congress.gov/crs_external_products/RS/PDF/RS22389/RS22389.71.pdf
- LIHTC oversight + QAP role (GAO, Dec 14, 2023): https://www.gao.gov/products/gao-24-107064
- IREM CSP v.2025 Multifamily Guidebook: https://www.irem.org/file%20library/globalnavigation/certifications/forproperties/csp/csp-multifamily-guidebook-v2025_ed_11.14.25.pdf
- IREM Profile and Compensation Study (IREM, 2024):
https://www.irem.org/learning/tools/research-and-reports/profile-and-compensation-study
This article was written by Todd Feist, Director, Sustainability Programs at IREM. Learn more about IREM here.
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