There should be terraced seating for the largest number of people you anticipate having in the choir, plus a little for growth. The organ console should be at the front centre of the choir seating. Do you anticipate using instruments from one great feast to another? If so, there should be space to seat half a dozen or so strings, plus space for other instruments, brass, for instance, and tympani. If you make space for instruments the organ console should be in front of their space (close to the gallery rail) so that you can direct everyone with ease.

About the organ - How many ranks do you think will be desired and feasible? if you anticipate 16' facade pipes you will need approx. 20 or more feet of ceiling clearance to accommodate them - assuming that the pipe feet will be a minimum of more or less three or four feet above the floor. If you only anticipate 8' facade pipes you would need proportionately less ceiling clearance. Too, you should allow a minimum of ten feet of depth for the organ, behind the choir seating. Actually, you should be deciding on your preferred organ builder right now, and have him and the architect working together. The organ should not be an afterthought in an already built building.

(Oh, and I forgot to mention that the choir gallery needs to be designed so that it has sufficient strength to bear the weight of the anticipated organ.)

Aren't Buzard and Berghaus pretty close to you? You should be able to get some good information from either of those firms, though I personally prefer Buzard between the two of them.

I was a bit concerned about those pew pads and the carpet. How are the acoustics in this place? That might require some reworking, too.

"The organ console should be dead center in the choir loft with the organist facing the choir" this works well if the ONLY Mass where the organ is played is the choir Mass.

Otherwise, an angled console that permits you to turn to the left and see the altar and to the right to conduct the choir when needed - is often a good compromise.

Seek out pics of St. Martins Episcopal Church in Houston, TX for ideas and thoughts as to lay out. I have been there and it is very nice in many ways.

While it is, indeed, a 'choir screen' it isn't really a 'rood screen' because it has no rood scene* atop it. I have been to many recitals and sacred concerts by visiting English cathedral choirs at St Martin's.

Reflected in the design of this church is the current fad in the Episcopal church for putting choir and organ at the (liturgical) east end, behind the altar and a choir screen. Choirs belong 'in choir' or in west galleries, not screened off behind the altar, which should be the eastern-most object in any church - eastern-most and without competition for attention. St Martin's was built this way. St John the Divine (on River Oaks Blvd.), which, like most Anglican churches, had originally a choir betwixt nave and sanctuary, was (sadly) renovated in this way about ten years ago. It represents current liturgical chic.

With all due respect plus some extra, I am surprised that Ken (of Sarum!) would regard this 'layout' as one to be mimicked in Catholic churches. As can be seen easily in the picture in Ken's comment, it is the organ (and the screened-off choir) which one easily could be led to believe was the object of worship. Notice how it dominates the area which rightly belongs to the altar alone, how it draws all attention to itself in a vista that should lead unmistakably to and focus solely on the altar and tabernacle. This is a fad which I do not recommend aping.
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*A rood scene is an image of Christ crucified (or, in ancient Anglican-Sarum practice, a Christus Rex) flanked by statues of our Lady and St John. A 'rood' is a cross. Instead of a rood screen, some churches have rood beams. The rood beam is a high and hefty beam crossing betwixt the north and south walls of the chancel and having a rood scene centred upon it.

Why don't you ask one of those firms you mentioned tp look at the church and sketch out a choir loft with organ? The organ builder should be very much involved in the design of the loft where the organ will be. The worst thing to do is to build the loft and then call the organ builder - it could be completely wrong. I would engage one of those firms (they are all good) to be in on the planning form the get go.

MJO - yes I know its just a choir screen and yes I know its not a "rood screen." I was up very very late when I wrote my suggestion. Also, its not MY ideal. My ideal is an Anglican gothic cathedral setting like Westminster Abbey or Chester Cathedral. However, considering all the architectural garbage I have seen, my intention in suggesting St. Martins was simply to point out the somewhat half wrap around shaped design; regardless of where its placed. Every time I see an altar placed out in front of a choir or rood screen, I sicken - I even feel uneasy looking at St. Peters Basilica.

By the way, and my poor memory is lacking lately, but isn't the choir area at Westminster Catholic Cathedral in London located behind the altar?

My suggestion would be to bull-doze most of these modernist ecclesiastical disasters and start over. Of course I realize that's not practical nor would it pass the bishop's approval / offices nor would a parish in most cases have the funds to raise a truly glorious edifice worthy as a work of praise and adoration. All too often pastors, prelates and peoples want something erected quickly. Most of us in the arts know too well, that the road to sloppy and ugly artistic expressions of any kind are the results of haste and cutting corners! I would rather a parish put all their wealth into restoring some of the old churches that sadly languish rather than seeing them decay or be sold off. Have you ever seen on youtube these young guys and gals that go around through Europe and here in North America filming old abandoned cathedrals, chapels and monasteries? The youngters shake their heads and can't understand why anyone would abandon what was once a beautiful structure. Many still have intact organs and great stained glass.

In my humble poor opinion, any and everything concerning the worship, praise and adoration of GOD should be of the finest, best and highest quality. It is our duty and responsibility to offer all to GOD in sacrifice. If the Mormons can erect gleaming white marbled and gold ornamented temples to "their" god, and Solomon spared no expense, then who are we not to strive towards the highest artistic expression in all the sacred arts.

PS - Although I use to be a choirmaster and organist, I'd much rather see a divided organ setup like at St. George's Chapel Windsor Castle or like in some Anglican gothic settings where the organ is decani - cantoris speaking back and forth in the monastic choir area AND at angles into the crossing.

Thanks for the information, pfeese. I was not aware that this arrangement had such a pedigree. I dare say, though, that neither choir nor organ in any way distract from or compete with the altar for attention in these churches.

Would the old tennis ball method work? Either that, or you just need to get felt feet for them which are common many stores.