Modernizing Existing Buildings

Holmes existing building modernization with seismic retrofit, residential conversion, and adaptive reuse. Pictured: 140 New Montgomery, San Francisco.

Take a look around our city centers and reimagine what is possible for our existing building stock. How might that stodgy office tower transform into a vibrant residential community? What if salvaging that unused warehouse created a space for public gatherings and greenery? We’ve found that most existing buildings are worth investing in. With a little optimism and clever design, we bring these buildings back to high occupancy and yield significant returns.

We must modernize more existing buildings for more compelling urban living. Centrally located, these properties sit by public transportation, freeways, workplaces, retail, and cultural centers. However, many are underutilized and could better spur social and economic growth. To make the most of them, let’s heighten their architectural and programmatic intrigue. Going further, let’s render them safe for occupants. Holmes is at the ready to facilitate structural, fire, and life safety upgrades for existing buildings—including seismic retrofits, adaptive reuse, and residential conversions.


Let’s partner in revitalizing our cities, one existing building at a time.


Seismic Retrofit and Adaptive Reuse for the Bay Area Metro Center
Bay Area Metro Center
Holmes Managing Principal Zander Sivyer onsite for an existing building modernization.

Building with what we have is the obvious choice to conserve resources.

We consider each building with the preference to supplement rather than replace, remove rather than add, and augment only in the amount necessary.

Zander Sivyer — Managing Principal

Sustainable Protection of Assets with Resilient Design


Performance-Based Engineering

Whether undertaking renovations or a full seismic retrofit, Performance-Based Engineering (PBE) is our preferred approach for understanding a building’s capacity. Through PBE, we leverage the strength of existing systems to minimize materials, costs, and time. Following an in-depth assessment of the building’s elements—down to its connection details—we input data to create a powerful base model. Through our analyses, we fully comprehend and depict the building’s expected performance in earthquake and fire scenarios.

With this level of understanding, we pinpoint upgrades to meet performance objectives alongside concurrent drivers: budget, schedule, architectural features, targeted sustainability benchmarks, and more. We adapt our models to showcase the implications of different design options including code alternates. These 3D representations of our structural, fire, and life safety solutions help establish consensus on project teams, as well as ease approvals.

Seismic Retrofit and Adaptive Reuse of The MacArthur in Los Angeles, CA
The MacArthur
Performance-based engineering non-linear analysis model of The MacArthur retrofit.
PBE model of strengthening scheme sensitive to historic fabric
Structural PBE Model of Seismic Retrofit
Structural PBE model of retrofit subject to ground motions
Performance-based engineering model of smoke spread at The Exploratorium, San Francisco
Fire PBE model of anticipated (compartmentalized) smoke spread
Natural Hazard Risk Assessments

With natural hazard risk assessments, developers and building owners can make long-term investment decisions in the face of climate change. We help our clients understand how a property’s natural hazards risk changes over time. We evaluate hazards that cause damage and loss events: earthquakes, wildfires, extreme temperatures, storms, winds, and floods. Then, we identify practical options for mitigation—backed by our structural and fire engineering expertise.

Holmes engineer assesses existing building conditions at Alta Star Harbor in Alameda, CA.
Site visit for seismic retrofit and residential conversion
Residential conversion of warehouse to housing Alta Star Harbor Alameda, CA
Alta Star Harbor

Facilitating Changes of Use with Return on Investment 


Adaptive Reuse

We’re partners in making changes of use economical. New occupancy may trigger a new risk category, which we discuss with stakeholders from the get-go. For whatever occupancy is selected, we look out for how we can add value for our clients. Often, we maximize the leasable area within a given building envelope through design-first thinking. We see former use cases as opportunities to reframe elements as strategic building blocks. In tandem, we infuse modern amenities and common areas where people mingle and exchange ideas—building community for the long-term.

Yotel: the conversion of historic offices into a modern hotel
Hospitality conversion office to bedroom hotel room seismic retrofit and adaptive reuse Yotel San Francisco
Holmes retrofit fit 203 units within the 75,000 SF Grant Building
Residential Conversions

For residential conversions—including those historic in nature—we optimize the number of appealing layouts for a return on investment. It’s no secret that we have a surplus of unleased commercial office real estate amidst a housing crisis in our West Coast cities. While we await tax incentives to mobilize more office to housing conversions, check out our Office to Housing study prepared in partnership with BAR Architects.

Residential Conversion and Seismic Retrofit The Pacific San Francisco CA

For residential conversions, we utilize Performance-Based Engineering to maximize saleable square footage. On The Pacific, we increased unit offerings with two new levels at the ground floor where the existing ceiling heights were generous. We also added a two-story grand penthouse.

Dan Bech — Principal
Residential Conversion and Seismic Retrofit of The Pacific in San Francisco, CA
The Pacific: a former dentistry school evolves into premier apartments
Residential Conversion Interiors at The Pacific in San Francisco
Interiors at the completed residential conversion of The Pacific
Seismic retrofit and adaptive reuse of The Battery San Francisco
The Battery: the seismic retrofit and adaptive reuse of a warehouse/offices turned social club

Best-in-Class Modernizations for Any Use Case

Across our portfolio, we safeguard and modernize existing buildings. We believe in their inherent value: lower carbon footprints, as well as inherent performance, architectural, and programmatic potential. Through our structural and fire engineering, we help owners, developers, project teams, and occupants contribute to an existing building’s legacy. We appreciate that each seismic retrofit, adaptive reuse, and residential conversion is an investment in our built heritage. Let’s bring these buildings back for best-in-class usage as originally intended. In doing so, we’re also investing in the future of our cities and our people to flourish for the next hundred years.

Seismic Retrofit of 140 New Montgomery in San Francisco CA
140 New Montgomery: our retrofit minimized costly additions
Seismic Retrofit of 140 New Montgomery - San Francisco, CA
and protected ornate art deco detailing
Holmes team onsite for seismic retrofit and existing building modernization
Holmes team onsite
Seismic Retrofit Adaptive Reuse Downtown San Francisco CA 140 New Montgomery

More Perspectives

We know we’re onto something when the engineering becomes a thing of beauty.

Women Engineers Advance the Profession