Frequently Asked Questions

About Purple Martin Housing

There are a number of questions about purple martin housing that are asked over and over by people interested in attracting them, so on this page I've placed the answers to a few of them in hopes of helping folks understand this hobby a little better.  If you have a question, take a look and see if your answer is here.  If not, then by all means, email it to me and I will attempt to answer it for you.

How high should I place my housing?

This is a personal preference and may even depend on the type and location of the housing. Assuming that your location meets all the needs and spatial requirements of the martins, then the most favorable height is around 12' to 15'. The housing can be placed as high as 18', but remember, the higher it is, the more susceptible it is to winds and also, the less you'll personally be able to enjoy them. I have a few friends that have their housing down as low as 10' and they are full of martins.

If you have a telescoping pole, then obviously, you will want to keep it lower. It would become very awkward and tiring to try and stretch a telescoping pole to 18'.

Martins do not mind nesting close to the ground as long as they feel safe, hence predator guards are a must. I've even seen them nest in a gourd that was attached to a 4' high page wire fence near a horse pen.

Shoot for the 12' to 15' range in height and your martins will do just fine as long as you keep any predators away.

How big should the entrance hole be for martins?

According to most old specification sheets available on this subject, the entrance hole for purple martins can be anywhere from 1 3/4" to 2 1/4" in diameter. Most commercial houses are sold with the 2 1/8" holes in them. If you're building your own, then the decision for the entrance hole is yours.

However, Please Note:

Because of the recent increase and infestation of European Starlings, it is now highly recommended that these round holes be changed to some form of Starling Resistant Entrance Holes (SREH).  A lot of testing went into a couple of different shapes to create an entrance hole that would keep starlings out of martin housing, and now a number of them are available and they work.  Of these, variations of the crescent shaped hole (shown here) has proven to be very effective as a deterrent for starlings and is quickly becoming the new standard for entrance holes for purple martins.  If you purchase a house or directions to build a house with round holes, then they are well behind the times and you should make the change to the new SREH's.  My entire site has been changed to these crescent shaped SREH's and is now starling free.  (Take a look at my T-14 page to see how I added them to my own T-14).  In fact, many sites in my immediate area have changed and they are no longer bothered by starlings entering the martin housing.

But I'm just starting out. Wouldn't it be better to start with round holes and then switch over to SREH's after the birds are established?

No. It was originally thought that a new site should start with the round holes and then change to the crescents after the birds settle in, but that theory is also now old school. It's being proven every day on new sites that martins, looking for nesting sites, will readily accept the SREH shaped holes and the round holes are being eliminated.  Martins do not look at the geometry of a hole, they only see a black opening and once they look in, know that there's an empty cavity suitable for nesting behind it.  It may take them anywhere from a few minutes to an hour or two to figure them out, but martins are fast learners and quickly learn to accept and negotiate the new style holes.  The following links will give full instructions on how to add crescent shaped starling resistant holes. 

This page will tell you how to add access ports and SREH's to Gourds.

This page shows how to add inserts to Wooden Housing.

This page will show you how to enlarge the compartments and then add SREH's to an Aluminum House.

One other note.  If you start out with Crescent SREH's, it will eliminate many of the problems you have with starlings right from the get go.  In fact, you'll actually enjoy watching the starlings as they are bewildered at these holes they can't get into.

And one final note:

Since all birds come in different sizes, even an occasional smaller starling may figure out how to get into one of these holes, but that is rare.  98% of all starlings are not able to negotiate these crescent shaped holes when cut to the right size and that's a heck of a lot better than letting the 100% in.  In all my time of having crescents at my site, only one starling was small enough to make it in, however; he is no longer with us today.  That's why their called 'starling resistant' and not 'starling proof'.

I've tried the new crescents on my gourds and they work great, but I've noticed one thing.  The birds go in real easy, but seem to struggle when coming back out.  Why is this?

The reason your birds seem to be struggling to come out of your crescent SREH is because the the entrance hole is of a different design.  What has been discovered is that these new holes require external 'and' internal porches.  Martins do not build a very elaborate nests and sometimes it's quite a bit below the bottom of their entrance hole.  This is especially true with deep gourds where the hole is high on the side.  An easy fix for this is to add the new entrances that are available that contain both the porches on them to begin with.  This page above for gourds shows them.  Then add enough nesting materials to come up to the bottom of the porch.  If you do not normally add nesting material to your housing, then this is a good time to start, especially since it's now so easy to get into your gourds.  I always add fresh nesting material to all my housing each spring and the birds seem to really appreciate it.  I keep some extra on hand just to build the nests up a little just in case they pack down too much.  Their constant walking on them will soon pack the nesting material and this is another good reason for using material that drains well.  I also keep a raised platform with more material on it just in case they want to add any final touches to their nests.

Which is better for martins, gourds or houses?

This is a question that has been debated for years by purple martin lovers and it still isn't answered today, so let me just say this.

What do you want to use?

I have three different kinds of houses at my site, wooden houses, natural and plastic gourds and I can honestly say this. I see no difference in gourd selection, natural or plastic, when the gourds are of the same size.  However, they will almost always choose a larger gourd over a smaller gourd.  I also have two wooden houses and I have martins that seem to prefer the wooden houses. But this is in my area.  Martins in your area may prefer something different and if you offer different styles of houses, I'm fairly sure that you'll see the same things from your own martins.  And as for aluminum houses that seem to have problems attracting martins, I do know that enlarging the compartments to 12" deep and hanging 4 large natural gourds under them will help attract them faster.  If you've purchased or have an aluminum house that only has the small 6" x 6" compartments, then they need to be REWORKED to the larger compartments.  Tests have proven that this will also help attract your martins much faster.  The new deeper compartments allow for the martins to back out of the reach of most predators that come visiting.

And one more thing.  When you enlarge your compartments, make sure you make the change to SREH's.  Starlings also love those enlarged compartments and will move right in on you if given the slightest chance.

Another issue to consider is a factor of 'area imprinting'.  Martins in the northern latitudes are much more used to wooden houses while many martins in the southern latitudes are use to gourds.

I simply say put up what works for your area.  Martins from around you are used to that type of housing and will more readily move in.

Still another issue to bring into this debate is the arrival of the new plastic gourds and houses. Again, this is personal preference and you will have to decide which you want to use.  The best thing to do is supply a variation of housing and see what the martins in your area prefer.

I want to use gourds, but don't know the best way to hang them.

Here you go.  This shows how I hang mine. Let me add one thing. Make sure when you complete the hanging, that the gourd 'swings, without twisting'. Although the swinging won't prevent the starlings from nesting in them, (another myth), sometimes it helps.  As for swinging from front to back or side to side, that doesn't matter.  You may read that a gourd should swing from side to side and not front to back for various reasons, but that has no foundation.  Martins could care less which direction a gourd swings.  They are much more interested in what's inside.

Starlings also love to nest in large gourds and this applies especially to the ones that are hung horizontally and tied down where they are stable.  As far as all tests show, starlings will take these horizontal gourds first and once established, will not vacate them. Although this method may look aesthetically pleasing, it makes for a starling haven, so if there is a starling problem, then SREH's should be added to your gourds.

I bought my house.  Now, where should I put it to have the best chance of getting martins?

This one's hard to answer without actually being there and seeing the setup, so here are a few quick tips on locating any purple martin housing:

-Martins like wide open spaces, so with that in mind, the house should be placed in a very open area, but within site of your own home..

-Martins hate tall trees.  The house should be no closer to a tree than the tree is tall, further if possible.

-Martins like water, (not bird baths), so if you have clean, open water available (a pond or river) within a mile or two, then that will be advantageous in attracting them.

-Martins like power lines.  If you have some readily available, they will use these to perch and preen on.

-Martins like to see people, so the house should be located near your own house.  30' is not an uncommon distance with the average being under 100'.

-Martins like human activity.  No, it won't hurt to have the kids running around or you out in the garden.  Near a driveway or back deck is also good.  However, please note.  Banging or swinging on the pole is NOT GOOD.  This will upset the martins and if it continues, they will leave.

I've read where some folks say that PVC pipe could be used to make less expensive martin poles.  Is this a good product to use for a pole for my housing?

As far as I'm concerned, NO!  PVC, (Poly Vinyl Chloride) pipe is no where near strong enough to use for martin housing.  Here's a couple of reasons why.

One, PVC becomes very brittle in sunlight.  Most PVC pipe does not have UV (Ultra Violate) inhibitors and will quickly become extremely brittle.  Once this happens, even just a sudden change in temperature could make it fail and the next thing you know, your housing will be on the ground.  Although seemingly strong when new, this quickly changes when the sun starts shining on it for any length of time.

Two, PVC pipe has a very low Modules of Elasticity (one of the numbers used in the calculation of material strength) and thus, has no structural strength.  Because of this, a sudden wind could quickly snap the pipe, (known as catastrophic failure in engineering terms).

Three, a long piece of PVC pipe is very flexible and the house would become very unstable, especially in any kind of storm.  A sudden strong gust at the wrong time will put your martin housing on the ground, along with everything in it.

I am a Mechanical Design Engineer by trade and believe me, the best thing to use for a martin pole with gourds is a good schedule 40 round steel pole.

All wooden houses should use at least a sched 80 round steel pipe because the loads are much higher.

Square pipes are also available, but make sure they are plenty strong enough to handle the loads of your housing.

For many of the commercial housing, triangular pipes are used and the are designed specifically for those types of houses.  Some come with a galvanized coating and may be used just like that or may be painted to your favorite color.  It might cost a few dollars extra to get a good pole, but the piece of mind that comes with it is worth every penny.

I've noticed that all your gourds and housing are painted white.  Is there a reason for this?

Yes, and in fact, there's actually a number of reasons for this. 

One, martins nest in the summer and that's the hottest time of the year.  White is the most reflective color there is and thus, reflects the heat of the sun.  We all know that the darker the color, the more heat is absorbed, so with that in mind, try to imagine a baby bird in a dark colored bird house with all that heat and being unable to escape it.  For that reason alone, all martin housing should be painted white.

Two, white stands out.  Incoming martins can see it from a long distance away and it really helps to draw them in.  Then, once they arrive, the dark entrance hole really contrasts the white gourd or house and they can zero in on it when making their landings.

Three, white just plain looks good.  Kind of like sparkling clean so to speak.  When you see something white, it reminds you of 'new and shiny'.  The roof and trim can be of any color you like, but the main house should always be white.

I've heard that the light interiors help keep starlings out.  Should I paint the insides of my house white, also?

No!  First of all, I don't know where that statement about 'white keeping starlings out' came from but it isn't true and has no testing basis at all.  Starlings could care less what color the insides of their compartment is as long as the size fits their needs.

Secondly, all birds like to have the interior of their nesting cavities dark.  But if a white one is all that's available and they want to nest in that house, then they will, bright interiors and all.

When I went to buy an aluminum house, the saleslady said that aluminum helps keep the nests free from mites.  Is this true?

Absolutely not!  She is only trying to make a sale.

First, the lady at the bird house store needs to be educated about the birds she's selling housing for.  (Or at least be truthful).  Mites will infest any type of bird housing REGARDLESS of the type and that includes the aluminum house she is trying to sell you.  Mites are brought into housing by the adult birds and then make their homes in the nesting material and since all martin housing has nesting material, then you can have mites.

Second, there are a number of different myths being passed around about martins and their types of housing, and unfortunately, a lot of them are not true and this is one of them..  As stated above, you'll also hear that the bright interiors of aluminum houses helps keep out starlings.  That is also false.  The only thing that helps keep out the starlings is the 'small' compartments in some of the commercial houses, which by the way, also works to keep martins out of the housing as well.  Many a potential landlord has emailed me wanting to know why martins will not nest in their aluminum housing like the advertising stated and all I can do is be truthful and tell them that, most of the time, it's the small compartments in their houses.  (I've also suggested that they email the manufacturer and ask them the same question).

Just remember, when you are purchasing a martin house, the person selling it to you is a 'salesman' and will tell you 'what you want to hear' so that you will buy his or her product.  This is why we, as potential landlords, have to educate ourselves about this hobby before we begin spending time and money.  As I've stated before, this is the way myths get started.  Someone that has no idea of what they are talking about, says something off the wall and of course, it spreads throughout the martin world.  This is why I say, talk to the experts, not your neighbor and definitely, not a sales person.

Is there a perfect martin house?

The 'perfect' martin house would be very difficult (and expensive) to design and build but I will say this, we are getting there.  Some of the houses built by newer and more educated manufacturers today are much better than others.  With today's increased knowledge of martins and hosting them, there have been a number of very good improvements in the housing industry by manufacturers that have decided to take the martin's best interest in the building of  their products.  However, there are still some that refuse to improve their houses and some of these that are offered for sale are absolute death traps for martins and in my opinion, should not be allowed to be put on the market for sale.  I just wish there was a 'code of conduct' required for martin house manufacturers to follow, but there isn't.  Their 'main goal' is still the 'bottom line'.

I won't mention any names, either good or bad, but as I've stated before, please educate yourself first.  Then, look for quality.  You might have to pay a little more up front for a quality house, but many years down the road, that quality house will still be doing its job where as the cheap ones will just be adding to the sparrow and starling slums or the junk piles.

So, what should I look for in a 'quality' martin house?

Although I say this throughout my pages, here's a condensed summary of what to look for in a good quality martin house.

-First, look at the over all design and structure of the house.  Is it sturdy?  Is it made from strong materials that will last for years out in the elements?  Cheap houses are much more costly than good quality houses in the long run.

-Does it have the new recommended 'deep' compartments?  Compartments that are at least 9" or 10" deep to allow the martins to back out of the way of any entrance hole dangers.

-Does the house either come equipped or have the capability of changing the holes to the recommended Starling Resistant Entrance Holes?  If it only has the capability of round holes, then look for another house.

-Does the house raise and lower vertically on a pole?  Houses that tip or worse yet, are hard mounted are not good designs and you should stay away from them.  These type of houses are bad in the fact that they are not easily accessed and the other competitor bird species will soon take over your new house and there goes your chances to get martins.

-Does it open easily for nest checks and maintenance?  Houses that do not open easily should not be used for martins.

-Does the house have the martins' best interest in the design or does it have the manufacturer's best interest designed into it.  I simply don't like 'cheap' houses.  I've seen what a Great Horned Owl can do to a cheaply made martin house.  And yes, you do have some around your area, you just don't see them because they are creatures of the night.

Martin houses that do not have these features should be left right on the shelves.  Somehow, the retailers have to get the point that these houses are not any good for martins and if we hit them where it hurts (in their pocketbooks), then just maybe they'll get the message.

When should I put my housing up?

OR

When should I open my housing?

Both of these questions go hand in hand and again, the answer to these questions have changed.  It was once thought that if you don't already have an established site, that you should wait 4 weeks after the arrival of the first scouts and then open your housing, but that thought has changed in the last 20 years of testing.

First, look at the map on The Martin Bio Page . Find the area on the migration map where you live and the approximate time the scouts (first birds to return) come through your area and have your house up and open.  It has been found that many times you'll pick up some adult birds that were misplaced from other sites.  Sometimes adult birds are misplaced for whatever reason, (old housing full of pest birds, old housing removed, or any other number of reasons).  If nothing shows, it won't be long before the SY (Second Year) birds will be coming through your area and they are the ones that usually settle new sites, but not always.

We've had our housing up for years and have never gotten martins to nest even though we seem to have the perfect place for them.  They come and visit and will even hang around for awhile, but always leave without staying.  What's wrong?

There could be any number of reasons, but if I had to guess, I'd have to say it's probably the housing.

First, does your housing have those small compartments spoke about above?  That could be one of the major reasons.  Although the housing manufacturers say that the 6" x 6" x 6" compartments are recommended, they are incorrect.  (6" x 6" x 6" compartments are cheaper to manufacture).  Remember, adult martins average 7 1/2" long, kind of hard to fit into a 6" x 6" space.  Martins need more room.  This is one of the major problems in the martin house industry and a few are still refusing to change. 

There could be other reasons, but first, enlarge your house compartments by removing the back wall (or drilling a hole in it) to make the compartment 12" deep, then be sure to plug the opposite hole so it can't be used, add SREH's and then sit back and watch what happens the next time a martin visits.

Our house is new and the very first bird to visit is an all black male.  Does that mean that he came from another site?

To be honest, there's no telling where he came from, but here are a few possible answers.

-He could be from another site that was either lost or over run with pest birds.

-There's even a good possibility that he and his last year mate tried to nest in that old site but were unsuccessful and he decided to find a new one.

-He could be a SY male from last year that was unsuccessful in attracting a mate and decided to look elsewhere and your site just happened to be it.

-He could be a migrating male that simply decided to not return to his original site and decided that yours looked better to him and he wants to stay.

As you can see, there are a number of different scenarios that could be looked at and all are just guesses.  These are wild birds and there's no telling what they have on their minds or what makes them move or stay, but at least you have an idea of what the thought process is that you have to go through to figure it all out...

Which direction should I face the holes in my house?

I personally don’t see any difference as far as the compass direction. However, I do see a difference when it comes to accessible flyways. My racks offer 360 degree accessibility and almost always, the gourds chosen first are the ones that are most easily accessible. Face your house to the open flight paths and you should do just fine.

One other thing to note.  I have noticed that, with my own colony, the birds will often pick the larger gourds (and house compartments) that are facing my own house.  I can't prove anything with this, but just maybe they want to see their landlord and know that he or she is around.  It might have something to do with the protection thing of human activity keeping away predators and it also makes for much better viewing on my part.

I have a night security light on my property.  Will this bother them?

No, not at all.  In fact, I also have one and it's less than 5 paces from my nearest rack and house.  I don't see any difference in their nesting habits at all.  In fact, the main power and T V cable lines to my house use that nightlight pole and so do the martins for perching.  I have a number of pictures with them sitting right on top of the light.  Martins are not the least bit afraid of man's modern technologies.  They only know that some of it keeps predators away and that makes them feel a lot more secure.

I decided to go with plastic gourds, but they're very white on the insides.  Should I paint the insides with dark paint?

No, that is not required.  Martins will use them just the way they are.  In fact, since the introduction of the 'larger' plastic gourds by the 'responsible' manufacturers, the martins have loved them.  With these new gourds and their easy accessibility, it's a very good way to keep martins. 

And besides, these new gourds are made with polyethylene with UV inhibitors, and they're so slippery that your paint would fall off within a short time anyway and now you'd have paint chips in your nests.

One particular manufacturer (S&K) has even developed a gourd that has a dark inner lining in it and it has proved to be a very popular gourd at my own colony.  I had 6 of them up last year and every single one of them was used.

However, one thing I would add is a good thick bedding of pine straw or wheat straw.  The insides of these gourds are so slippery that the martins are not be able to get a good foot hold, so a thick layer of one of the above will make them feel a lot more at home.  I always add a good bed of nesting materials to my housing, regardless of what it is.  I add enough to bring the level up to the bottom of the internal porch.  They will work the materials to what they want and it will save them time in nest building in the long run.

What about perches?  If I add them to my gourds will it help me attract martins?

Actually, this is now a new discovery.  PORCHES, not 'perches' are now considered a must for housing using the new Starling Resistant Entrance Holes.  Testing has now proven that both external and internal porches set between 1/4" to 1/2" under the bottom of the SREH entrance hole enhances the compartment or gourd and also allows for much easier access into them.  Pest birds such as Sparrows and Starlings will also use these porches, but if the SREH works, then the starlings can't get in anyway.  Also, if the sparrows sit long enough on the porches, they make easy targets for pellet guns or guns of other sorts. 

Martins LOVE roosting perches and these are usually placed somewhere convenient to the gourds or housing and they will be used quite extensively by the martins to do their sunning and preening and just general socializing.  These can be long rods in starburst patterns or crossed bars or what ever you decide to make yours look like.  It gives the birds something to land on when they fly into the site.  From that point, they will fly down and light at the entrance hole.

What are predator guards?  Should I use them?

Martins are communal nesters and of course, when you get a large group of any kind of birds or animals together, then there are predators that take notice.  There are a number of different flying and ground based predators that martins need to be protected from.  Snakes, raccoons, cats, squirrels to name a few.  Owls are also a major night time predator that can wipe out a colony in short order.  The proper guards need to be in place to keep them from gaining access to your martin housing.

Should you use them?  Absolutely!  It only takes one attack from a predator to make a hard earned colony vacate a site and in most cases, never to return.

Why is so much literature being written about enlarging the compartment sizes of houses?

A lot of study has gone into this subject and the results now show that martins prefer the larger cavities, say 6" x 6" x 12".  A long time ago, some aluminum house manufacturers decided that the size of a martins' nest should be 6" x 6" square.  How they derived this number isn't exactly known because the parent birds are around7 1/2" to 8" long, but it probably had something to do with the cost of building their houses.  The less material used, the more profit for them.  That just isn't enough room for two adults to raise a brood of babies.

Recent testing put large compartments beside small compartments and just about 100% of the time, the larger compartments were chosen.  When given the choice, they took the larger, deeper cavities over the smaller ones.  This allows them to get back out of the way of predators, something they can't do with the smaller cavities.  In fact, this is one of the major reasons people that have these type of houses can't get martins to stay.  However, if the compartments are enlarged, they often move right in.  And, further studies have shown that the nests are always at the back of the deep compartments, thus confirming that the larger compartments are better, something that can't be done with the smaller ones.

We want to add new housing.  Is this going to bother the martins when they return?

    Or

What about adding new housing to an active site?  Is that a problem?

Absolutely not and in fact, if you already have martins, then they will be the first birds to investigate the new nesting possibilities.    If you put it up while they are watching, they'll probably just sit quietly by and watch the entire project.  Then, a moment or two after you've walked away, they'll start investigating.  

It doesn't hurt at all to add new housing to a site and in fact, it's actually better.  It enhances the options the birds see for nesting cavities and the more they see, the better chances of either attracting them or enlarging an existing colony.  If you want to enlarge by adding new housing, then go for it.  Adding housing can be done at 'any' time of year, even during nesting time.

We want to move our martin housing to the other side of our house.  Will this be a problem?

Maybe, maybe not.  Martins, as well as all other birds, have very good homing instincts and as far as they are concerned, that exact spot is their home.  If you move it very far, then they may abandon it.  I know because, not knowing any better at the time, I tried to do this many years ago when I moved my T-14 and the original martins didn't even look at it in its new location.  In fact, they would fly to the exact same spot it originally stood and just hover where the house used to be.  New birds had to come and settle in the house before the new activity drew the old birds to the house.  I came within a wing beat of losing part of my hard earned colony.  I only had 2 pair in the house at the time, but it taught me a lesson.

However; if you move it only a little way, say 5 to 10 feet, then there is a good chance they will except the change, especially if it's towards a spot that's more out in the open.  They will see this as a change for the better and may readily accept the change.  But don't be surprised to still see them flying to the old 'spot' to look for their house until they get used to the new location.

But, can the housing be moved and still keep our colony? 

Yes, but there is a method that should be followed.  It should to be done in steps and will take a couple of years.  And, the distance can only be a short one for it to work.

First, you'll need to get another house and put it up in the new spot where you want the housing to be located. 

Second, when the birds return, open all of the new house to them, but only half of the old house.  When they fill all the available cavities in the old house, they'll begin looking for more room and will actually find and settle in the new house.  (This is assuming that the new location is to their liking and they will settle in it).  Now you have birds in both houses and they consider this to be 'one' site. 

Third, once incubation has started, plug any compartments in the old house that are not being used.  Now, let the birds fledge the young from the old house.

Fourth, once the birds have gone for the year, remove the house from the old location.  You now have your martin house in its new location.  If you like, you could even put the old house up in the new location if you think you want more birds.

The birds are gone. Does anything need to be done with the housing?

Now that the birds have left for the year, it's a good idea to lower the housing and thoroughly clean it out. This is a good practice because it removes any parasites that may be in the nesting material. Whether it be houses or gourds, remove the nesting materials, clean out any debris from the inside and then store in a dry out of the way place until next year. If you are using natural materials such as wooden house or gourds, this will make them last many years longer than if they were left out in the open. Storing your housing also helps to keep the pest birds out of your area since they have no place to hang out.

I have two houses at my site and I leave them out year around.  They are both made of Western Cedar and it is a good wood to use out in the elements.  It has natural resins that protect the wood for many, many years.  Taking down and then putting back up martin houses is a chore, but there are many folks that do it every year.

My housing doesn't lower. How can I clean it out?

If your housing doesn't lower, now is the time to correct that. Many martin houses were built like this and if you have one of these, it should be upgraded to a manageable house, one that raises and lowers vertically.  Tests have proven that landlords who manage their colonies have larger and healthier broods and much better fledging numbers than those that just let nature take its course.

Here are a couple of tips.

If possible, rework your housing so that it can be raised and lowered, either by means of a rope and pulley system or a winch and cable system. This may mean replacing the pipe or pole with one that allows the use of such a system. (Tilting systems are not acceptable. The eggs or young could be dumped out of the nest).

Rework the housing so that you have access to it once it is lowered such as hinging the front faces. This should be done so that the nests are not disturbed when opening the house. This will allow for nest checks and nest replacements if necessary.

If not already, rework the housing so that it has compartments larger than 6" x 6". This will make room for larger broods and allow them to back out of the way of danger should it happen by.  Many times this can be done by simply drilling a 2" diameter hole in the back wall and then plugging the opposite hole.  This allows the martins to pass thru the back wall and nest in the rear cavity.

If your housing is not of this nature or can't be reworked, then serious consideration should be given to replacing the housing totally. Nesting time is a very dangerous time in a birds life and we should do everything we can to keep them safe.

The old ways of keeping martins are a thing of the past. The hobby of keeping purple martins has advanced significantly and our education of the subject has also increased. The many tests that have been done in recent times have proven that a managed colony has much better results at years end and will grow with each succeeding year. It also makes the hobby much more fun.

I want to change my martin house. Do I take the old one down and replace it with the new one?

Depends... If you didn't have any nesters in your house, then it's simply a matter of taking the old one down and putting the new one up as you said.

However, if you did have nesters the previous year, then it's a little more complicated. Your site is now established and the birds are familiar with it and any major or drastic changes in housing could cause partial or even total abandonment of a site by the established birds.

If the new house is a major 'upgrade' (better house), then it probably wouldn't bother them at all.  They'd probably take the change in stride.

But if the house is of a totally different style, then you might want to try it first and see what happens.  Here is what could be done to give it a test.

First, set the new housing up very close to the first house, say within a couple of feet or closer if possible. Then, let the birds spend a summer getting used to and moving into the new housing. Block off any unused compartments in the old housing. This will help force any newcomers to the new housing.
Then, after the summer is over and the birds are gone, the old housing can be removed and the new housing can now be moved a couple of feet to stand in the place where the old one was.  That short of a move will not bother the martins at all. Now, when the birds return the following year, they will already be acclimated to the new housing and won't mind the gentle transition from 'old' to 'new'.

However, if the new housing is going to be the exact same style of house, then it probably wouldn't matter to the martins if you made the change.  The only major difference would be a new house.