Building Biology Standards (SBM-2015), Explained

SBM-2015 is the measurement standard used by building biologists, consultants who inspect homes for clients who want their exposures as low as reasonably achievable. For EMF, it grades sleeping areas into four bands, from “no anomaly” up to “extreme,” using targets hundreds to thousands of times stricter than the official FCC and ICNIRP limits.

Here is the important part to understand up front: SBM-2015 is a precautionary philosophy, not a set of health limits. It does not claim that official levels cause harm, and it was not derived the way government limits are.

This page explains what the standard actually says, where its numbers come from, and how to use it without misreading it, in either direction.

Key Takeaways

SBM-2015 grades sleeping areas into four bands: no anomaly, slight, severe, and extreme.

Its targets are precautionary goals built on the question “how close to natural background can a bedroom get?”, not on established harm thresholds.

It is voluntary guidance for consultants and homeowners. Nobody enforces it, and it is not a legal or medical standard.

These are the targets I lean toward in my own home, more than the official limits, though I treat them as a direction rather than a test to pass.

What Building Biology Is

Building biology (Baubiologie) started in Germany in the 1960s and 70s as a movement focused on how buildings affect the people living in them. Today, trained building biologists inspect homes for a range of concerns: mold, air quality, radon, and EMF among them. In the US, training and certification run through the Building Biology Institute.

The field’s guiding idea is simple to state: nature is the reference. A building biologist’s goal is to get a living space, especially a sleeping area, as close to natural background conditions as is practical. That framing matters, because it explains everything about the numbers you are about to see.

What SBM-2015 Actually Is

SBM stands for Standard der Baubiologischen Messtechnik, the building biology measurement standard, with 2015 marking its current major revision. It covers far more than EMF, but the EMF sections are why it appears all over this site.

For each measurement, the standard defines four bands for sleeping areas:

No anomaly: at or near natural background; the ideal

Slight anomaly: minor elevation; precautionary reduction is suggested where practical

Severe anomaly: clearly elevated by the standard’s philosophy; reduction recommended

Extreme anomaly: the standard’s highest band; prompt action recommended

Note the word: anomaly, meaning a departure from natural background. That is what the bands are built to describe. The standard sets its numbers by how far a room sits from natural conditions, not by any threshold it claims to have identified.

The Numbers (Sleeping Areas)

Here are the EMF bands most relevant to a home, in the units used throughout this site. Verify against the current SBM-2015 tables before relying on them; the standard is periodically revised.

RF power density (µW/m²)

Band	Level
No anomaly	below about 0.1
Slight	about 0.1 to 10
Severe	about 10 to 1,000
Extreme	above about 1,000

AC magnetic field (mG)

Band	Level
No anomaly	below about 0.2
Slight	about 0.2 to 1
Severe	about 1 to 5
Extreme	above about 5

AC electric field (V/m)

Band	Level
No anomaly	below about 1
Slight	about 1 to 5
Severe	about 5 to 50
Extreme	above about 50

What That Looks Like in a Real House

My own, measured over two evenings in August. The full room-by-room figures are in What Is a Normal EMF Reading in a House?.

Where	Reading	SBM band
Pillow beside the bedroom access point	over 20,000 µW/m²	extreme
Pillow in the bedroom across the hall	82 to 196 µW/m² peak	severe
Magnetic background, every room	2 to 4 mG	severe
Electric field, middle of a room	0 V/m	no anomaly
Electric field, inch from a lamp cord	221 V/m	extreme

For scale on that first row: the official public RF limit works out to roughly 10,000,000 µW/m². So a pillow next to a busy access point sits at about 0.2% of the FCC limit and twenty times above the top of SBM-2015’s extreme band, at the same time.

Both facts are true at once, because the two benchmarks measure against different reference points. Neither one is lying about the reading. They are answering different questions about it.

The magnetic row is the one that surprised me. My whole house runs 2 to 4 mG with nothing switched on, which puts every room in the severe band for a quantity I have not yet traced to any appliance.

Where These Numbers Come From (and Where They Don’t)

The official limits, meaning the FCC rules in the US and the ICNIRP guidelines most other countries follow, come from a documented recipe: find the lowest established harmful effect, which for RF means tissue heating, divide by a safety factor of 50, and write the rule. In the FCC’s case that happened in 1996, and the rules have been reaffirmed rather than re-derived since. ICNIRP issued its guidelines in 1998 and revised the radio-frequency portion in 2020.

SBM-2015 does not follow that recipe, and the standard itself is honest about this. Its guidance values come from the field experience of building biologists, from what natural background looks like, and from what is achievable in real buildings. The standard’s own text describes the values as precautionary orientation for sleeping areas.

That is both the standard’s honest limitation and its honest purpose. It is not evidence that official limits are wrong; it never claims to be. It is an answer to a different question: if someone wants maximum margin in the room where they sleep, what does low actually look like, in numbers a meter can read?

A Fair Critique, Both Directions

The skeptical case: the bands are not derived from harm thresholds, so a label like “severe” describes how far a reading sits from natural background rather than a measured level of risk. Someone reading the word without that context can come away more alarmed than the number warrants.

In an apartment or a dense neighborhood, the RF “no anomaly” band can be out of reach whatever you do, because signals arriving through the walls already exceed it. A detached house with distance from neighbors has a better chance. Either way, anyone using the standard should know that the lowest band is not always available.

The other direction is fair too: the standard is transparent about what it is, its bands give cautious people something concrete to measure against instead of vague dread, and its emphasis on sleeping areas focuses effort where exposure time is longest. As a tool for turning “I’d like it lower” into a number, it works.

The mistake, in both directions, is treating the bands as medical findings. They are a ruler, not a diagnosis.

How I Use SBM-2015 in My Own Home

These are the targets I lean toward, more than the official limits, and I say that plainly because it is a preference rather than a finding. I still treat them as a direction, not a pass/fail test.

My own bedroom does not sit in the “no anomaly” band for RF, and given what arrives through the walls it may never. Nor does any room in my house for magnetic field. Knowing that has not sent me shopping. It has told me where to point my attention.

What the bands are genuinely useful for is naming the size of a change. A pillow reading that moves from one band to the next is a result you can describe without claiming anything about health. That is the whole use case, and it fits my rule: when a change is free or easy, I make it, and when it costs real money I want better reasons.

The two obvious candidates in my house, moving that access point and relocating the charger at the headboard, are jobs I have measured the before on and not yet the after. When I do, the numbers go on this site either way, including if they disappoint me.

Frequently Asked Questions

Is SBM-2015 scientifically proven?

Its bands are not derived from established harm thresholds, and the standard does not claim they are. They are precautionary orientation values built on natural background and field experience. The measurements themselves use the same physics as any other measurement; it is the targets that reflect philosophy rather than proven effect levels.

Who enforces SBM-2015?

Nobody. It is voluntary guidance used by building biology consultants and homeowners. It has no legal force anywhere, which is another reason it should never be confused with regulatory limits.

Can a city apartment reach the “no anomaly” band?

For magnetic and electric fields, often yes, with free changes. For RF, frequently not, because neighboring networks and nearby infrastructure set a floor you cannot control. That is not a failure; the bands are a direction, and moving down one band is a real, measurable result.

Do I need a professional to measure against SBM-2015?

Certified building biologists carry meters more sensitive than consumer meters, and the RF “no anomaly” band sits near the floor of what hobby meters resolve. For seeing which band your bedroom is in, and whether a change moved you down one, a good consumer meter does the job. What Is an EMF Meter and Which Type Do You Need? covers what to look for.

You now have one of the two benchmarks in full. The readings from a real house, sorted room by room, are in What Is a Normal EMF Reading in a House?, and learning to take those readings yourself starts with How to Read an EMF Meter.