The practical guide to building monitoring for small commercial buildings.
Most buildings under 100,000 square feet have no building automation system. That does not mean they have no options. FractionalBAS.com publishes vendor-neutral, research-backed guidance on environmental monitoring, indoor air quality, energy efficiency, and building controls for the buildings that full BAS was never designed to serve.
No product endorsements. No sponsored content. Sources cited.
What Do You Want to Learn?
Everything on this site is organized around six topic areas. Each hub contains foundational explainers, data roundups, and practical guidance. Start with the topic most relevant to what you are trying to solve.
What Is Fractional BAS?
The core concept behind this site: a practical middle ground between individual spot sensors and full building automation systems. Start here if you are new to building monitoring.
Building Automation Systems
What a BAS is, how it works, what it costs, and why 87% of small commercial buildings don’t have one. Covers controllers, protocols, and the total cost of ownership reality.
Indoor Air Quality
CO2, humidity, VOCs, particulate matter, and the standards that define acceptable levels. Covers ASHRAE 62.1, OSHA guidelines, WELL certification, and how each parameter affects occupant health and productivity.
Energy Efficiency
Where commercial buildings waste energy, how much it costs, and what monitoring and controls can realistically recover. Grounded in DOE and PNNL research on actual savings potential.
Building Monitoring
What building monitoring is, what it measures, how sensor networks work, and what separates a useful system from a dashboard full of numbers nobody acts on.
Compliance and Standards
ASHRAE 55 and 62.1, WELL, RESET, NYC Local Law 97, OSHA IAQ guidelines, and federal sustainability requirements. What applies to your building and what monitoring evidence you need to demonstrate compliance.
Evaluating Your Options
If you are actively comparing monitoring systems or building automation options, the guides section covers the purchasing decision directly: how to evaluate vendors, what full BAS actually costs, and what to look for in a contract.
How to Choose a Building Monitoring System
A six-criteria evaluation framework with vendor questions and red flags. The starting point for any purchasing process.
Fractional BAS vs. Full BAS
A head-to-head comparison across cost, capability, complexity, and building size fit. Includes a 12-row comparison table and a four-question decision framework.
All Buying Guides
The full guides section, including a realistic BAS cost breakdown and a structured buying checklist covering requirements, evaluation, vendor assessment, and contract review.
Your Building Type Has Specific Needs
Building monitoring requirements vary significantly by use. A commercial kitchen has different temperature and humidity concerns than a school or a warehouse. The verticals section covers the specific regulations, energy profiles, and monitoring applications for seven common small commercial building types.
Schools
K-12 IAQ requirements, absenteeism research, HVAC energy savings potential (48.8% per DOE), and ventilation compliance.
Office Buildings
Productivity, CO2 and cognitive function, tenant comfort, and the business case for monitoring in small commercial offices.
All Building Types
Municipal buildings, food service, healthcare outpatient, warehouses, and hospitality — each with vertical-specific guidance.
Who Publishes This
FractionalBAS.com is operated by Xmark Labs, LLC and written by building monitoring practitioners and technical writers. All content is reviewed against primary sources before publication. We do not accept sponsored content, and we do not endorse specific products in our editorial content.
The site is editorially independent from Xmark’s commercial products. Some pages include a clearly labeled reference to Nosy™, Xmark’s building monitoring platform, as a “recommended solution.” All other content is vendor-neutral by design.
Read our editorial standards, meet the authors, or get in touch with questions or corrections.