Engineering Luxury Residential: Inside ColeBreit's Approach to Comfort at Scale

ColeBreit Engineering has spent more than a decade quietly shaping some of the most complex luxury homes on the West Coast. These are projects where comfort, aesthetics, and technical performance must all operate at a very high level. Now, as the firm expands its residential portfolio, Principal and Project Executive Kate Hillard is helping articulate what truly sets ColeBreit apart in the luxury residential market.

Deep experience in large, highly customized homes

Hillard’s pathway into this niche began in the late 2000s, working with long-standing clients in Northern California’s luxury enclaves, including San Francisco, Napa, Sonoma, Pebble Beach, and the Santa Lucia Preserve. “It will be 20 years this year for my role in the combined company,” she notes, reflecting on her tenure through Axiom Engineers’ merger into ColeBreit.

The homes she and her teams work on are often far beyond typical residential scale. “We design homes on the large side, often over 10,000 square feet, with some reaching 20,000 square feet,” Hillard explains. At that scale, “these homes require commercial building systems to provide the level of comfort and the level of control that this type of client requires.”

That commercial‑grade mindset, applied to private residences, is one of ColeBreit’s core differentiators. Their mechanical, electrical, and plumbing (MEP) designs must seamlessly support:

• Extensive artwork collections with specific temperature and humidity requirements

• Dedicated wine rooms and other spaces with tightly controlled environmental conditions

• Increasingly common wellness spaces, including saunas, cold plunges, and spa environments, indoors and out

  
  

“We’re accustomed to working with the installing contractors for those specialty-type systems,” Hillard says. “We understand what the utility needs are for the systems we’re designing and how they connect to what’s being provided by the installing contractor.”

Systems tailored to how each client actually lives

Every project begins with a detailed MEP questionnaire that surfaces how the owners will truly use and occupy the home. “We really need to understand the client drivers before making assumptions about the type of system that we decide to design,” Hillard emphasizes.

That early discovery focuses on questions such as:

• Is the residence a primary home, a seasonal retreat, or one of several properties?

• Will there be a full-time facilities team, or will systems need to operate reliably with minimal on-site oversight?

• How much direct control do owners want over their environment, such as simple thermostats, tablet-based interfaces, or full building management systems with remote monitoring?

On the mechanical side, ColeBreit often designs a few types of systems:

• Air-side systems such as VRF (variable refrigerant flow), increasingly paired with air-to-water heat pumps as regions move toward electrification

• Hydronic overlays that deliver radiant floor heating, particularly in mild-climate areas where heating is more dominant than cooling

• Variable air volume systems, similar to those used in commercial buildings, that provide zonal control while also providing robustness, a high level of acoustical properties, and static pressure capacity needed for more complex projects.

Adaptability and the willingness to change system strategies based on owner needs and regional climate requirements are other distinctive aspects of ColeBreit’s approach. 

Craftsmanship behind the walls: aesthetics and acoustics

For owners investing heavily in architecture and interior finishes, mechanical and electrical systems must disappear visually while remaining highly responsive. Hillard sees engineering craftsmanship as inseparable from that in the built environment.

“From a mechanical system standpoint, we understand that our design significantly impacts the aesthetics of the home,” she explains. Early in design development (DD), ColeBreit initiates conversations with architects and interior designers around:

• Decorative vs. subtle air distribution: grills, linear slots, or hidden terminals

• Whether any devices can be visible on walls and ceilings, or whether everything must be fully concealed

• How equipment placement and duct routing can support the intended interior design language

“Once the interiors come into play, then we massage what we’ve shown from a dimensional standpoint to ensure that our systems are blending in or disappearing into where the interior direction is headed,” Hillard says. “It’s not an afterthought for us.”

Acoustics are treated with equal care. ColeBreit routinely adjusts duct velocities, terminal selections, and equipment locations to protect peace and quiet in bedrooms, living spaces, and wellness areas. That sensitivity extends to:

• Locating fans, pumps, and manifolds in well-insulated mechanical rooms

• Collaborating with architects and acoustical engineers on noise criteria for key spaces

• Addressing subtler sources of sound, such as LED drivers or radiant floor actuators in acoustically sensitive rooms

Proactive utility and code coordination

Another defining characteristic of ColeBreit’s luxury residential work is how early and thoroughly the team engages with utilities and local jurisdictions. In Northern California, coordination on electrical and gas service can easily fall onto the critical path for both design and construction.

“It’s really important to start talking about electrical and gas service needs early on,” Hillard says. “With the industry push towards electrification in some areas, that electrical piece is becoming a first-day discussion.”

Codes and local ordinances are treated as design drivers. “We’ll start looking at local ordinances early in SD so that we can help inform the project team if there are any new code changes that may impact the design of the building.”

This proactive stance extends to resilience and climate-responsive design. In Northern California’s Wildland Urban Interface (WUI) zones, ColeBreit helps architects and contractors select exterior terminations and vents that minimize wildfire risk. “The architects and contractors are leaning on us to understand what types of grills and terminations on the outside of buildings will help limit destruction during a wildfire,” Hillard says. That includes minimizing vents and using metal screens to reduce ember intrusion into attics.

Filtration has become another major theme. “Filtration for wildfire smoke wasn’t really a conversation when we first started, at least in San Francisco, and now that’s something that we’re asking about on every project,” Hillard notes. 

Building on those wildfire-focused strategies, ColeBreit also considers how homes must adapt to broader climate volatility, including hotter summers, more severe smoke seasons, and the potential for extreme events. By pairing high-performance envelopes with flexible mechanical systems, ColeBreit can shift a home’s operating profile over time, enhancing cooling capacity, tightening filtration, or adjusting ventilation strategies as local conditions evolve. Thoughtful integration of backup power, smart controls, and zoned distribution allows owners to maintain safe, comfortable refuge spaces even during prolonged smoke or heat waves. Beyond meeting today’s codes, ColeBreit engineers residences that remain healthy, livable, and efficient in a future where environmental baselines are a moving target.

Photographer: Cheryl McIntosh

Flexible, collaborative delivery for a moving target

Perhaps the most subtle but crucial differentiator for ColeBreit in the luxury market is the firm’s attitude toward change. High-end residential projects can have one- or two-year design phases, with significant decisions still being made after construction has started. Consumer technologies, owner expectations, and regulatory frameworks all evolve during that window.

“We understand that change occurs more rapidly with high-end homes than in non-residential projects,” Hillard says. “We know to expect that there might be curveballs every once in a while. We’re flexible and willing to adapt and be a good team partner.” From Hillard’s perspective, this collaborative stance is essential to successful luxury residential work. 

ColeBreit Engineering brings a rare combination of technical rigor, aesthetic sensitivity, and long-term, climate-aware thinking to the table.