Semmes & Co. Builders
Semmes & Co. Builders is a private, California Central Coast construction firm founded in 1978 that designs and builds custom green residential homes and select commercial projects using passive solar design and thick-wall construction methods such as straw bale, rammed earth, and ICF.
- Company typePrivate
- Founded1978
- HeadquartersAtascadero, United States
- Headcount11–50
- GTM typeB2B and B2C
- OfferingServices
What Semmes & Co. Builders does
Semmes & Co. Builders is a privately-held, employee-owned construction firm founded in 1978 by Turko Semmes and headquartered in Atascadero, California. The company builds custom green residential homes and select commercial projects (wineries, schools, retail centers) on California's Central Coast, with a focus on passive solar design and unconventional thick-wall construction methods including straw bale, rammed earth, ICF, SIPs, and PISE. Its operational scope is limited to San Luis Obispo County, serving high-end residential homeowners and a small portfolio of commercial clients.
The company generates revenue primarily through one-time, quote-based custom home construction and remodeling contracts, supplemented by a recurring tiered Home Management Program (Steward, Safeguard, Maintain) that provides annual preventative maintenance to existing clients. Since 2011, ownership has transitioned from founder Turko Semmes to an employee-owned structure, and in summer 2021 Jessica Steely became sole owner-operator and CEO. The firm relies on a sales-led, consultative GTM model, working directly with homeowners, architects, and designers from site selection through construction, with strong reliance on architect referrals, client testimonials, and a portfolio-driven reputation.
Semmes & Co. operates without external institutional funding, M&A activity, or geographic expansion. Its core technical differentiation is grounded in building science expertise — balancing passive solar orientation, thermal mass, ventilation, and indoor air quality — accumulated over 40+ years and recognized through awards including USGBC Green Home of the Year (2011) and Custom Home Pacesetter of the Year (2007). Co-founding roles in the California Straw Building Association and SLO Green Build further institutionalize the firm's leadership in sustainable construction on the Central Coast.
Semmes & Co. Builders firmographics
Firmographics- Name
- Semmes & Co. Builders
- Legal name
- Semmes & Co. Builders, Inc.
- Website
- https://semmesco.com
- Company type
- Private
- Founded year
- 1978
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Semmes & Co. Builders is a private, California Central Coast construction firm founded in 1978 that designs and builds custom green residential homes and select commercial projects using passive solar design and thick-wall construction methods such as straw bale, rammed earth, and ICF.
- Ownership category
- akta.pro rank
Semmes & Co. Builders industry classification
Industry- Product category
- Green Construction Services
- NAICS
- New Single-Family Housing Construction (except For-Sale Builders) (236115), Residential Remodelers (236118)
- SIC
- General Bldg Contractors - Residential Bldgs (1520)
- akta.pro primary industry
- Residential Green / High-Performance Home Construction (Net-Zero, Passive House) (IMAFABAH)
- akta.pro secondary industries
- Custom Home Building (IMAFABAC), Residential Luxury / High-End Home Construction (IMAFABAJ)
Keywords
Where Semmes & Co. Builders is headquartered
LocationHeadquarters
- HQ city
- Atascadero
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
Semmes & Co. Builders business model
Business model- GTM type
- B2B and B2C
- Offering type
- Services
- Cost components
- Personnel, Supply Chain, Operations, Marketing or Sales, Others
Revenue model
- Custom Home Construction: New custom residential home construction with high-quality, non-toxic building materials. Homes generally utilize passive solar design principles and variety of construction methods including conventional framing, straw bale, insulated concrete forms, and rammed earth.
- Home Remodeling Services: Kitchen and bath remodeling, room additions, complete home renovations. Specializes in making existing homes more energy efficient while reusing and revitalizing existing structures.
- Commercial Construction Projects: Green commercial construction including wineries, private schools, and energy-efficient retail centers.
- Home Management Program: Tiered annual preventative maintenance plans (Tier 1 Steward, Tier 2 Safeguard, Tier 3 Maintain) plus à la carte services for home maintenance, inspections, and repairs.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | Annual | Home Management Program - Tier 1 Steward |
| Subscription | Annual | Home Management Program - Tier 2 Safeguard |
| Subscription | Annual | Home Management Program - Tier 3 Maintain |
Go-to-market motion1 record
Distribution channels1 record
Marketing channels4 records
Semmes & Co. Builders product offering
Product offeringCore offering
Semmes & Co. Builders is a green construction company that designs and builds custom residential homes and commercial buildings using sustainable methods. Core offerings include custom home construction, home remodels, green commercial construction, and a recurring Home Management Program for ongoing preventative maintenance. Specialty capabilities include passive solar design, thick wall construction (straw bale, rammed earth, ICF, SIPs), off-grid energy systems, and indoor air quality management.
Product overview
Semmes & Co. Builders is a green construction company offering custom home building, commercial projects, and a home management program. The core offerings include Custom Homes and Commercial Projects, supported by specialty services in Building Science, Passive Solar Design, Thick Wall Construction Methods (including Straw Bale, Rammed Earth, ICF, SIPs, PISE, and Masonry), Off-Grid Energy Production, Indoor Air Quality, and Unique Details. The Home Management Program provides ongoing maintenance services. The company was founded in 1978 and operates on California's Central Coast.
Differentiator
Problem solved
Functional benefit
Products and services
- Custom Homes Custom residential home construction services specializing in green building and energy-efficient homes using a variety of construction methods including conventional framing, straw bale, insulated concrete forms (ICF), and rammed earth, designed for high-end homeowners seeking sustainable, passive solar residences.
- Commercial Construction Projects Green commercial building construction for wineries, private schools, retail centers, and other commercial structures, with a focus on energy efficiency and sustainable building practices; serves commercial property owners seeking distinctive, energy-efficient facilities.
- Remodels Home remodeling services including kitchen and bath renovations, room additions, complete home renovations, and energy efficiency improvements for existing structures, offered to existing homeowners on California's Central Coast.
- Home Management Program Recurring preventative home maintenance program offering tiered annual subscription plans (Tier 1 Steward, Tier 2 Safeguard, Tier 3 Maintain) plus a la carte services covering electrical, HVAC, plumbing, utilities, cleaning, weatherization, doors and windows, appliances, and sitework, providing existing homeowners with a single point of contact.
Quantifiable outcome
- Passive solar design can save homeowners approximately $2,000 per year in energy costs, totaling $100,000 over 50 years
- +2 more outcomes
Companies that use Semmes & Co. Builders
Customer profileNamed customers5 records
Segments3 records
Ideal customer profiles3 records
Semmes & Co. Builders technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
Semmes & Co. Builders partnerships and signals
Strategic signalPartnerships
Three partnerships are on record, tiered notable and core.
- California Department of Forestry and Fire Protection (Cal Fire)notableContracted to design and build the Fire Safe Demonstration Building at California Mid-State Fairgrounds in Paso Robles to educate the public on wild fire-resistant construction practices.
- California Straw Building AssociationcoreCo-founded by Turko Semmes, the company's founder. The association promotes and supports straw bale construction methods and sustainable building practices in California.
- SLO Green BuildcoreCo-founded by Turko Semmes. Local organization promoting green building practices in San Luis Obispo County.
Scale indicators3 records
Recent moves6 records
Expansion highlights3 records
Semmes & Co. Builders competitors and assessment
Company assessmentEmerging players
- Method Homes: Washington State modular and prefab builder focused on sustainable, high-performance residential construction with West Coast delivery — overlapping end customer but different delivery model.
Direct peers
- BPC Green Builders: Bellingham, WA-based custom builder specializing in high-performance, energy-efficient homes using passive solar, ICF, and SIPS — directly comparable niche and method mix to Semmes & Co.
- Green Hammer: Portland-based design-build firm focused on net-zero, passive house, and sustainable custom residential construction on the West Coast, with overlapping service offerings and customer profile to Semmes.
- Living Stone Builders: North Carolina-based custom builder focused on high-performance, energy-efficient homes using advanced framing and building science — comparable technical depth in green residential construction.
- BrightBuilt Home: Maine-based net-zero home builder specializing in high-performance, energy-efficient custom homes with an integrated design-build model — closely comparable mission and customer segment.
- Padulla Custom Builders: Boutique custom home builder emphasizing energy efficiency, healthy indoor environments, and high-end finishes in the California/West Coast market — overlapping luxury and sustainability positioning.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat3 records
Key risks5 records
Key highlights6 records
Customer concentration
Semmes & Co. Builders social profiles
Digital presenceSemmes & Co. Builders financial estimates
Financial estimateRevenue estimate
Valuation estimate
Semmes & Co. Builders leadership team
Management profileNumber of profiles
Profiles13 records
Semmes & Co. Builders funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Semmes & Co. Builders M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Semmes & Co. Builders
What does Semmes & Co. Builders do?
Semmes & Co. Builders is a green construction company that designs and builds custom residential homes and commercial buildings using sustainable methods. Core offerings include custom home construction, home remodels, green commercial construction, and a recurring Home Management Program for ongoing preventative maintenance. Specialty capabilities include passive solar design, thick wall construction (straw bale, rammed earth, ICF, SIPs), off-grid energy systems, and indoor air quality management.
Is Semmes & Co. Builders a public or private company?
Semmes & Co. Builders is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was Semmes & Co. Builders founded?
Semmes & Co. Builders was founded in 1978. It employs 11 to 50 people.
Where is Semmes & Co. Builders based?
Semmes & Co. Builders is headquartered in Atascadero, United States, in the North America region.
How does Semmes & Co. Builders make money?
Four revenue lines are on record. Custom Home Construction is the primary driver. The others are home Remodeling Services, commercial Construction Projects and home Management Program.
Who are Semmes & Co. Builders's main competitors?
Method Homes is listed as an emerging player. Direct peers are BPC Green Builders, Green Hammer, Living Stone Builders, BrightBuilt Home and Padulla Custom Builders.
Does Semmes & Co. Builders have an API?
No public API is recorded for Semmes & Co. Builders.
What industry is Semmes & Co. Builders in?
Semmes & Co. Builders's product category is Green Construction Services. Its primary akta.pro industry code is IMAFABAH, Residential Green / High-Performance Home Construction (Net-Zero, Passive House), with a secondary code of IMAFABAC, Custom Home Building. Its NAICS code is 236115 and its SIC code is 1520.