even if i bought wood.. to make it last.. i would have them potted in plastic and insure there were a lot of drain holes in the wood ... so it stayed as dry as possible .. so determination of the planter size.. would be a function of the pot size ... if that makes sense ... so.. at a min.. i would be thinking about a MINIMUM of a 25 gallon black pot ... see link.. no clue if that is a good price.. i got most of mine from recycle bins .... but i dont use them decoratively ... and that one is already 25 inches wide at the top .... any even in nurseries.. plants of the size you want.. BLOW OVER.. wind and stability are going to be your BIG PROBLEM ... especially if you buy them big ... and i should also point out.. that conifers have very specific potting media issues.. and what you fill the pot with will also be very important.. and its not going to be your standard bag of potting media .... i am sure you can do it.. but i doubt you are going to find the info you need here.. with the specificity you wish .... i simply dont think us tree peeps are going to have a lot of specific info for you ... other than to list the variables .... good luck ken ps: winter storage will also be an issue .... Here is a link that might be useful: link -- you shop price.. i am just showing the pot

why renovate them.. if you dont solve the deer issue ... something similar happened at hidden lakes.. and i believe it took upwards of 5 years.. for them to do the job themselves.. i mean for the plants to fill back in ... because frankly.. there is nothing you can do.. other than protect them from repeated damage ... if it were me.. i could not look at that for the next 5 years.. and i would be looking to replace them with something that is more deer proof ... and i dont know if that is possible ... WELCOME to GW .. i hope we can enable you ... but in this case.. we need to start by figuring out.. if you really want to look at these for the long run ... ken

the little round ones are also conifers.. MAYBE something like a Thuja occidentalis globe ... there is some named varieties.. but i cant differentiate ... the JMap's .. as trees.. can be pruned away from the house in an artful arching style.. so they should be fine right where they are ... with that size arb .. see my prior post... IMHO.. its not worth the labor... get rid of them .. yes.. the last are alberta spruce.. or picea glauca conica .... i dont know why you keep saying everything is off topic.. relax.. now.. i would double the bed out front ... and plant basically in the middle.. with things that are DWARF ... so that you have access behind them for maintenance .... just try to remember.. foundation plantings are planted to HIDE the foundation.. not ON THE FOUNDATION... and that is the error the prior owner made ... dont replicate it ... and dont make the worst mistake.. of shopping for replacements at the bigboxstore [or you will just end up with a bunch of arbs and albertas and globes] .... there is a world of conifers out there.. that can make a wonderful addition to the front of your house.. just flip thru a few pages of the posts here in the conifer forum .... but you will have to mail order.. or find local upscale nurseries to find the unique stuff ... good luck ken ps: i love teal.. but i dont know about the shutters.. lol ... and presuming [hopefully] that it is another prior owner issue.. you might want to think that part out ... and if it is your choice.. its the best color scheme i ever saw ... Here is a link that might be useful: link

we need your location. big city name.. to discuss plant vigor ... they have the potential to get bigger than the space allotted ... they are conifers.. and they are trees.. they do not stop growing at some magical height ... they are prone to severe snow and ice load issues ... they can be sheared if you dont mind signing up for that lifetime job ... its not easy to water new transplants or tree with irrigation .. such will like a deep drink thru the root mass and then near dying before the next deep drink ... its easy to do.. if all the plants on the line are trees.. but if you start mixing other types of plants with differing water needs .. there can be problems ... and just forget about soaker hose.. put in proper irrigation lines .. you can work it out that they just connect to a hose.. like a soaker hose would.. but such would provide proper water along the whole line.. soaker hoses.. as they get longer.. might not water the last plant.. like the first plant ... big box ought to carry such ... frankly.. with the nice fence.. i might just skip trees.. and put in flowers ... just a lot less problems all around.. imo ... just thinking outside your box ... of.. and as to your actual question.. lol .. spacing on new plants of the same size.. simply depends on your goal .. do you want an immediate sight line block.. or do you want to wait for them to grow together?? .. and how fast they grow together is a function of where you are .. bam.. full circle .. lol ... ken ps: this is how i look to future potential and note i used the proper latin name: https://duckduckgo.com/?q=Thuja+occidentalis+%27Smaragd%27&t=ffcm&iax=images&ia=images