I'm not sure I understand your concerns about the berm. Because it provides additional height to otherwise flat ground, it will immediately help to create a taller privacy screen. If properly constructed, a berm does not present any more difficult a growing condition for plants (in fact berming is often recommended to alleviate poor planting conditions) nor should it adversely affect drainage.

Based on the information provided, I'd say some careful thought has already been given on how this structure would impact neighboring properties. Obviously plantings on the development side of the line will not take place until construction is complete, but you can jump start the process by considering what to plant on your side now. And I wouldn't necessarily restrict myself to evergreens - columnar forms of deciduous trees can provide a measure of privacy as well while not eating up major portions of your property. Specially since evergreens are contemplated on the development side. A backdrop of something like columnar European hornbeams (Carpinus betulus 'Frans Fontaine') will still provide substantial screening potential and allow for lots of layered planting areas in front. Plant now to achieve some growth before the new development is complete.

Thank you, that's a pretty tree. I appreciate your thoughts on berms. I have been eyeing them hard in my area-- some, especially those that vary in height and have a mix of plantings on them, are quite nice. I've seen others where they've had to replace plants several times because they've died. I prefer a natural mixed look versus a line of ajuga or leyland cypress, but I'm not sure how choosy I can afford to be with my narrow back yard.

Conifers used for screening are often really dull and unnatractive (like those awful leyland cypress, which are everywhere in the U.K.)

If your back yard is narrow, what about using climbers to hide the view? You'd get a good variety of colour and seasonality, with small space take up.

I'd need a climber to 45', unfortunately!

Does anyone know where I can see pictures or a landscape plan for a mixed border good for screening-- deciduous trees + conifers and shrubs, preferably something with some flowering interest and attractiveness to birds?

I hope the developer handles the staggered evergreens for you so that you don't have to go to that expense. The Thuja plicata 'Green Giant' are quite fragrant, more hardy than leylands and grow 5ft a year here in zone 7. If he plants those, then you can use ornamentals on your side.

I would also ask how you want to use your backyard? You can create and screen outdoor rooms much easier than screening your entire property line. It sounds like you don't want to see the structure at all from your house.

For different textures (to prevent the row of soldiers look on your side):

There are some clumping bamboos, like Bambusa glaucescens 'Fernleaf' which grow to 10x6. They sway in the breeze, the birds love to hang out there, they are evergreen.

Osmanthus fragrans is a wonderful evergreen, fragrant shrub that grows to 25x15.

Cryptomeria japonica 'Sekkan Sugi' 30x15, has very graceful needles.

You can mix these evergreens in with some ornamentals:

magnolia virginiana: sweetbay magnolia, semi-evergreen, fragrant blossoms in March. Can take wet feet or not. 30x20

Chionanthus retusus: Chinese fringetree, deciduous, fragrant in May/June, well-drained soil. 20x15.

Evodia danellii : Korean Evodia, deciduous, average/fast growth, white flowers in summer, red fruit after. 30x30.

Franklinia alatamaha: Franklin tree, deciduous, fragrant July/August white flowers. 20x15

hepaticodium miconiodes: seven-son shrub, deciduous, fragrant white flowers. 20x10

Vitex (chaste tree)

Large buddleia (butterfly bush)

Betula nigra Fox Valley 'Little King' is 10x12.

Cercis canadensis 'Covey' is a weeping form 6x8.

Magnolia x 'Ann' is 10x10

Prunus x 'Snow Fountain' is 10x15.

A layered "woodland" border of the trees and shrubs suggested by Wonbyherwits would be a lovely screen. However, the clumping/non-running bamboo on the list, Bambusa, is not hardy in zones 6 and 7. It needs zone 8. A fine substitute non-running bamboo is Fargesia rufa (6-8' tall and as large around) or Fargesia murielae (12' tall and wide). They are evergreen. The F. rufa is a fast grower and forms a dense screen.

Oh, I'm glad you're looking for variety - my main desire was that you didn't just see a bunch of overweening leylandii! (Which are almost always used, if its a conifer screen).

The developer will planting the screen of conifers on their side of the development, so the input the homeowner/OP may have on that selection could be limited. I think conifers will still make the most efficient screen in terms of being both evergreen and the lowest maintenance (always a primary concern with a commercial development), but hopefully they will be a bit more creative in their choices and select from an assortment of firs, spruces or pines suited to the climate and location, rather than just leylands or Green Giants.

Locating a deciduous screen, like the hornbeams, on his side of the line will offer visual relief from the possibility that it is a leyland or Green Giant type of screen, yet allow sufficient space for the layered small tree/shrub border in front.

Personally, I'd be less inclined to be concerned about what happens on the developer's side as I would about selecting an appropriate and attractive screening plant and transitioning into lower ornamental plantings on the homeowner's side. For a 45' high screen along a 110' run, I think the OP would be better served by sticking with a single species and bringing the diversity in with the lower, layered plantings.

This is so helpful and encouraging, thank you. I knew I took a gamble when I built beside undeveloped land. I pretty much lost (50 feet from a 130' foot wide, 45' tall building), but I love my house so much and the location is otherwise great for us (right in town so my DH can walk to work). I really want to be able to make this okay so we can stay here and of course we don't want to take a nasty hit when we do sell the house. This is helping me feel there might be a light at the end of the tunnel.

The "final" plan is to be submitted to the township in April. It will include a landscape plan so I can detail what type of conifer they're proposing. I'm still torn between encouraging the township to require a berm, which will provide some instant privacy, with fear that trees on a berm will not grow as fast or as tall as those in the ground.

I looked up many of the plants on wonberherwits list-- I love the look of a layered, mixed screen. I would love for it to be flowering and fruiting as well. We are planning for a fence to contain our dog/children. I've been madly looking for existing landscape plans to give me ideas and I saw this one which has a little bit of the right feel:

http://www.bhg.com/bhg/story.jhtml?storyid=/templatedata/bhg/story/data/gp_FamilyBackyard_032505.xml&catref=cat10004

We do have a large front porch and a retention pond across the street where kids play kickball and go sledding, so I'm willing to give up most of my backyard to screening.

Does anybody use one of those computer programs for landscaping? Are there good ones?

A berm will not only give you some instant height to help screen visually, but will also reduce noise. You don't say how many units will be in the complex, but you will have at least some cars coming and going, and possibly headlights shining into your house depending on how the parking is situated.

demeron,
The following will have some contrary thoughts to be considered. At the moment this project, which impacts your enjoyment of property and resale value is still in the planning stage. You have a short time to influence the situation with the developer and planning board.

I see two pressing long range problems:

1. In your growing zone all evergreen, tall conifers lose their bottom branches as they mature through the years. So, what may shield you today, bermed or not, will thin out at the base in time.

2. Your overhead privacy is being invaded. It will be years before evergreens will provide protection from a three-story building.

Considering the above...I would request from the planning board the right to build a 6' high board fence along the rear property line. The uprights on this fence would continue up another 4' and a 6'-8' wide lattice pergola top would be constructed on them, providing overhead visual screening in your narrow back yard. This would allow you to train grapevines, autumn clematis, wisteria (if you are prepared to keep it controlled) or whatever type of vine you choose up, over and hanging from the pergola. An expensive solution but one which would reduce the fishbowl feeling and allow for enjoyment of your property.