DIY Home Efficiency Audit

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Lighting

Making your home more energy and water efficient is hands-down the best investment you can make to reduce your utility bills and carbon footprint. The payback period (the time it takes to recover your initial investment) for efficiency upgrades can be 7-10x faster than solar. We start with lighting, because it is one of the biggest energy users in the home and one of the easiest fixes to make. LED lights have one of the fastest payback periods of any efficiency product you can buy.

This handy guide will help you identify the lamps you need to make your home or workplace more eco-groovy and save loads of money. To begin, simply go through your space and take a look at what kinds of bulbs you have. Follow the steps below and we'll help you identify the bulbs you need, and give you information about the more efficient alternative that matches light output, color rendering index, size, shape, and purpose as closely as possible to what you have.

What lighting topics would you like to review before beginning?

You can close the instructional windows after you review them just by unchecking the boxes!

Bulbs to find (e.g., how to identify your inefficient bulbs)
Typical fixture and bulb types
Light spectrum and brightness
How to measure a bulb's size and base type

Bulbs to find
You'll want to get rid of incandescents and halogens. They come in a lot of different shapes and sizes (see below), but you can spot them because they tend to get very hot when they're on, and are usually very fragile/lightweight. In addition, incandescents may have visible filament threads. The real indicator is to look for the wattage (the energy the bulb uses), which is often indicated on the bulb either on the top or on the base. More info on that will be presented as you start to go through the audit below.

CFLs (the squiggly ones) you may *want* to replace for other reasons, and if so, the photos above should help you identify what types...CFLs will not follow the same measurement scheme as halogens and incandescents, however, since their bulb size/shape may vary.

Typical fixture and bulb types
There are a lot of different types of fixtures common in most homes. Some require unscrewing, some require removal of a faceplate, some simply pull straight down out of the ceiling. For the most part, though, the only thing you'll need to do is to identify the type of bulb within that fixture. Here's a diagram of common stuff you'll find.

Light spectrum and brightness
Light color is measured in a scale called "Kelvin" or "K". 2200K to 3000K color spectrums tend to be the "warmer" or "redder" lighting that you're probably most used to in indoor settings. 4100K is fluorescent tube lighting, typically, and 5000K and above are typically "bluer" and a little more harsh, thus they are used primarily for outdoor and security purposes. If you inspect a lightbulb package at the store, you'll see somewhere on it "2700K" or something like that. Here's a graphic:

Measuring a bulb's size
This is one of those things you scratch your head at and wonder why, but the way light bulbs are measured is in eighths (1/8th) of an inch. Does it make sense? No. Don't waste your time wondering why...unless you enjoy those sorts of pursuits. But for the purpose of identifying the bulbs you'll need, you'll need to understand how to measure appropriately. Here's a graphic.

The little tick marks on a ruler are 1/16th of an inch, therefore 2 of them would be 2/16ths, or more simply, 1/8th of an inch (left, above). Half an inch would be 4/8ths of an inch (right, above). Clear as mud? Good.

You'll be measuring these lights in two places...at the diameter, and at the base. Here's an example of measuring the diameter of a bulb:

Now, a normal person would look at this and say it's 2 and 3/8ths of an inch across. However, in bulb language, that's 19 eighths. Thus, this is a "19" diameter. Here's an example of a base type measurement:

That would be 1 inch...oh wait, sorry--8 eighths of an inch. Of course, the same people who brought you eighths of an inch as the standard measurement also thought they'd get creative with base types--which somehow are measured in millimeters. An E26 base type, which is pretty common, is 26 millimeters across. Amazing, right? These people are so smart! Rest easy--we'll walk you through it all.

I agree that I use this DIY audit tool COMPLETELY AT MY OWN RISK, NO MATTER WHAT HAPPENS!

It's time to start looking at the lighting in your house and identifying what could use an energy efficiency upgrade. But as always...SAFETY FIRST. That means no sticking your finger in a light socket (among many other things...). An additional safety tip most people don't think about with regard to lighting is if bulbs are hot, you can use gloves or silicon tongs to remove them, but have a towel handy to put them in so you don't burn your hand.

I agree--I take full responsibility for my safety and won't blame anyone for anything bad that could possibly happen to me.
I don't know (if you click this, you will not be able to proceed, and if you later click this, be forewarned, all your information will disappear...)

Your local electricity cost

We'd like to calculate the payback period of LED lighting and other home efficiency upgrades for you (you can also do it yourself with that link), but to do so, we'd need to know the price per kilowatt hour (kWh) you pay to your local utility. You can find this info via google or on your electric bill, usually. The average rate in the U.S. is about 13 cents / kWh, just to give you some reference.

Please enter your cost below IN CENTS PER KWH

Lamp types - SHAPE

Once you've had a chance to look around your house and pull out the incandescent and halogen lighting you found, simply review the sizes below and then check the boxes next to the types of lamps you might need based on the shape of bulbs you find. Don't worry about bulb size just yet...just use the shapes indicated below...more information will appear below to help make sure you buy the right kind of lighting.

A-shape (most common residential lamp type)

B-shape (candle-like, usually in chandeliers, ceiling fans, accents)

Globe-ish (very round, found in bathroom vanities usually)

Spot/focus lights (typically halogens, usually in track lighting)

Security/flat top/spot lights (usually outside/security lights)

Roundish-top but somewhat directionally focused (usually in recessed can/ceiling)

Tubes

A-shape
B-shape (candle-like)
Globe-ish
Spot/focus lights (small, usually halogen)
Security/flat top/spot lights (usually outside)
Roundish-top but somewhat directional (usually in ceiling/recessed cans)
Tubes
I have a bulb or bulbs that aren't listed here...

Bulb A

These are generally referred to as "A-shaped" bulbs (even though they look nothing like an "A"). Your priority for energy savings is incandescents and halogens, which will follow the measurement guidelines below.

Note below which of these you have...they are usually all the same size, but if you want to measure, the diameter should be 19 eighths or 21 eighths of an inch across and the base type should be "Medium screw base", which is just a hair over one inch long. If you want to make sure, it should be 26 millimeters across at its widest point. If you have bulbs that are 19 or 21 eighths of an inch at the diameter and 26 millimeters at the base, you can simply note below what wattages you have.

40 watts
60 watts (if your bulb says 43, that's a halogen but it's equivalent to 60, so choose this one in order to get the same amount of light)
75 watts (or 53 watt halogen)
100 watts (or 72 watt halogen)
3-way bulb: 30-60-90 watts
3-way bulb: 50-100-150 watts
Other Wattage
Other Base Type

Number of 40 watters

How many 40 watt bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Number of 60 watters

How many 60 watt (or 43 watt halogen) bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Number of 75 watters

How many 75 watt (or 53 watt halogen) bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Number of 100 watters

How many 100 watt (or 72 watt halogen) bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Number of 30-60-90 watt 3 way bulbs

How many 30-60-90 watt 3-way bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Number of 50-100-150 watt 3 way bulbs

How many 50-100-150 watt 3-way bulbs in this shape with 19 eighths of an inch as diameter and a medium screw base (26 mm) do you have?

Other, unusual A-shape bulbs

There are a wide variety of bulbs out there--if you have something that doesn't quite fit the above descriptions (or you just aren't sure), simply describe them as best as possible here, including the total number you have, and then take some photos and upload them below. We'll try to solve the riddle for you.

File

Drop files here or

Max. file size: 50 MB.

Bulb B

These are generally referred to as B-shaped or "candelabra" bulbs. These come in various wattages, shapes, and base types. The important first step is to identify which base type(s) you have. The one in the picture below-left is a "candelabra base" (12 millimeters, or about a half inch), and the one below-right is a "medium screw base" (26 millimeters, or just a hair above 1 inch).
*Note--there are other sizes...they're just really rare.

There are mainly two shapes (which you can choose later):

Below, you'll be given the option for shapes and wattage, but to start off, just identify which base types you have:

Candelabra base
Medium screw base

Candle shape with candelabra base

Identify below which bulbs you have of this shape

25 watters
40 watters
60 watters

How many **torpedo shaped** 25 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

How many **flame tip** 25 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

How many **torpedo shaped** 40 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

How many **flame tip** 40 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

How many **torpedo shaped** 60 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

How many **flame tip** 60 watt bulbs with 11 eighths of an inch as diameter and a candelabra screw base (12 mm) do you have?

Other, unusual B-shape bulbs

There are a wide variety of bulbs out there--if you have something that doesn't quite fit the above descriptions (or you just aren't sure), simply describe them as best as possible here, including the total number you have, and then take some photos and upload them below. We'll try to solve the riddle for you.

Photos of B-shaped bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Globe-ish bulbs

These are generally referred to as G-shaped or "globe" bulbs. These are usually found in bathroom vanities. The two most common shapes and base types are 25 eighths of an inch in diameter with a medium screw base (below, left) and 16 eighths (aka 2 inches) in diameter with a candelabra screw base (below, right):

Below, you'll be given the option wattage, but to start off, just identify which of these globe-ish bulb types you have:

Candelabra base and 16 eighths of an inch in diameter (2 inches)
Medium screw base and 25 eighths of an inch in diameter
Other--I have globe-ish bulbs that are different than these two sizes

Globe shape with candelabra base: 16 eighths of an inch in diameter

Identify below what wattage of these bulbs you have with a candelabra base

25 watts
40 watts

How many globe shape, candelabra (small) base bulbs of 16 eighths of an inch in diameter do you have that use 25 watts?

How many globe shape, candelabra (small) base bulbs of 16 eighths of an inch do you have that use 40 watts?

Globe shape with medium screw base: 25 eighths of an inch in diameter

Identify below the wattage of these bulbs you have:

25 watts
40 watts
60 watts

How many globe shape, 25 eighths of an inch diameter and medium screw base (26 mm)) bulbs do you have that use 25 watts?

How many globe shape, 25 eighths of an inch diameter and medium screw base (26 mm)) bulbs do you have that use 40 watts?

How many globe shape, 25 eighths of an inch diameter and medium screw base (26 mm)) bulbs do you have that use 60 watts?

Other, unusual globe-shape bulbs

Have a globe shaped bulb that doesn't fit the size of the two listed above? No problem! Just tell us about them, and take some photos to upload them below. We'll try to identify your bulb types and find you an LED that fits. Take measurements!

Photos of Globe-ish-shaped bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Spot / Focus lights (usually found in track and accent lighting)

These bulbs, which look a little like mini-satellite dishes, are used primarily to put light on one very specific spot--like a piece of art, or the spot on your kitchen counter where a cutting board might be used. They are typically halogen bulbs, using 45-55 watts, and are typically 16 eighths of an inch in diameter (2 inches). The only trick for replacing these bulbs with LEDs is to identify the right base type. The one below/left is like two little pins and the one below/right is like two little anchors:

Pick the bulbs you have that need replacing:

Two pins, 45-55 watts (above left)
Two little anchors, 45-55 watts (above right)
I have something completely different!

How many of these small spot light bulbs with 2 pins do you have?

How many of these small spot light bulbs with 2 little anchors do you have?

Other, unusual spotlight (satellite dish) shape bulbs

Have a spotlight/satellite dish shaped bulb that doesn't fit the size of the two listed above? No problem! Just tell us about them, and take some photos to upload them below. We'll try to identify your bulb types and find you an LED that fits. Take measurements!

Photos of spotlight-y bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Security / spotlight / beam lights (usually found outside)

These bulbs have a relatively flat top and are primarily used for producing a relatively narrow beam of light. This is good for specialized lighting needs inside, but mostly for security in outside lighting. These are the most common types of bulbs found in motion sensing lights, for instance.

Virtually all of these types of lights have a medium screw base (26 mm across), so if you have a light of this shape with a different base, pick the "I have something completely different!" below where you can upload a photo and we'll try to figure out what you have.

Pick the bulbs you have that need replacing:

16 eighths of an inch in diameter (usually 45-70 watts)
20 eighths of an inch diameter (usually 50-70 watts)
30 eighths of an inch in diameter (usually 70-90 watts)
38 eighths of an inch in diameter (usually 85-120 watts)
I have something completely different!

How many flat top / security style lights do you have that are 16 eighths of an inch diameter?

How many flat top / security style lights do you have that are 20 eighths of an inch diameter?

How many flat top / security style lights do you have that are 30 eighths of an inch diameter?

How many flat top / security style lights do you have that are 38 eighths of an inch diameter?

Other, unusual security / flat top shape bulbs

Have a security / flat top shaped bulb that doesn't fit the size of the two listed above? No problem! Just tell us about them, and take some photos to upload them below. We'll try to identify your bulb types and find you an LED that fits. Take measurements!

Photos of security / flattish top bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Do you want the replacement lights for these flat top / security lights to be primarily 4000 - 5000 K (cool white)?

These lights typically are higher on the lighting spectrum scale, since they are primarily used for really making something "pop" (either specialty lighting inside or security lighting outside). If in doubt, please go to the top of this page and check out the lighting spectrum information.

Yes, I want cooler white in the 4000K to 5000K range for all these bulbs
I'd prefer at least one of these to be in the warmer white range of lighting color

Round-ish top but somewhat directional (usually in ceilings/recessed cans)

These bulbs have a relatively rounded top and are primarily used for producing a broader beam of light but still providing focus light for an area. These are the most common types of bulbs found in recessed can lighting fixtures.

Virtually all of these types of lights have a medium screw base (26 mm across), so if you have a light of this shape with a different base, pick the "I have something completely different!" below where you can upload a photo and we'll try to figure out what you have.

Pick the bulbs you have that need replacing:

16 eighths of an inch in diameter (usually 45-70 watts)
20 eighths of an inch diameter (usually 50-70 watts)
30 eighths of an inch in diameter (usually 70-90 watts)
40 eighths of an inch in diameter (usually 85-120 watts)
I have something completely different!

How many round-ish top but still somewhat directional style lights do you have that are 16 eighths of an inch diameter?

How many round-ish top but still somewhat directional style lights do you have that are 20 eighths of an inch diameter?

How many round-ish top but still somewhat directional style lights do you have that are 30 eighths of an inch diameter?

How many round-ish top but still somewhat directional style lights do you have that are 40 eighths of an inch diameter?

Other, unusual round-ish top shape bulbs

Have a roundish top shaped bulb that doesn't fit the size of the sizes listed above? No problem! Just tell us about them, and take some photos to upload them below. We'll try to identify your bulb types and find you an LED that fits. Take measurements!

Photos of round-ish top but still directional bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Long skinny tubes

These bulbs are very distinct, so you should be able to easily identify them. The savings on this type of bulb when switching to an LED are minimal--since these are fluorescent tubes, they're pretty energy efficient to begin with. An LED replacement might pay for itself, depending on how much the light is used, in a few years, whereas many of the rest will pay for themselves in a year or less. These bulbs are more typical for office buildings but are found in the home in places like the laundry room or kitchen.

Virtually all of these types of lights have a bi-pin base on each side, so if you have a light of this shape with a different base (or different size than listed below), pick the "I have something completely different!" option and then you can upload a photo and we'll try to figure out what you have.

Pick the bulbs you have that you might want to replace:

2 foot long (usually 17-20 watts)
4 foot long (usually 32-38 watts)
I have something completely different!

How many 2 foot tube lights do you have?

How many 4 foot tube lights do you have?

Other, unusual tube shape bulbs

Have a tube shaped bulb that doesn't fit the size of the sizes listed above? No problem! Just tell us about them, and take some photos to upload them below. We'll try to identify your bulb types and find you an LED that fits. Take measurements!

Photos of tube bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

Other, unusual bulbs

Got something totally unique? There are a LOT of different types.

No problem! Describe and upload photos below and we'll see if we can help. Don't forget to take measurements!

Photos of bulbs you have that don't quite fit the descriptions above

Drop files here or

Max. file size: 50 MB.

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