The artificer is a class all about crafting. Not just magic items but ordinary items as well. This includes castles. Thanks to the spell transmute rock you have access to magic cement.
First create a wooden mold with fabricate. Then fabricate a bunch of rebar from junk metal, placing the rebar in the mold. Then fill that mold with rocks of any shape or size. It is best to use the same type of stone and if you want the strongest stone then use granite. When the mold is filled with rocks hit them with transmute rock into mud. Mix the mud together then smooth it out to get a flat top like cement. When it is the way you like it use dispel magic to turn it back into stone. Instead of a bunch of stones you have one big stone ready to be part of a castle. Transmute Rock has an area of effect that is a 40 foot cube so you can get large parts of the castle done in a single day.
This can all be done by one artificer if they have a portable hole and an all-purpose tool. It makes transporting the stone and even placing it very easy depending on what your DM rules on how gravity works in a portable hole. If the gravity of a portable hole matches the outside when open then you could place it on a light 6 foot board and flip it over. You could lift huge blocks of stone and drop it anywhere you like.
Then there is the cantrip mold earth. You can use it to excavate dirt into the portable hole which you then dump else where. You can get the spell with the all-purpose tool for eight hours a day. You can excavate a basement or just a foundation that you create with transmute rock.
Next the spell wall of stone. The transmute rock spell you can create unique shaped stone but if you just need walls then the wall of stone spell is great for fast fabrication of walls. The stone the wall are made of are the same as the stone it comes out of so it should match.
Finally the spell stone shape. Use this spell to do fine detail work like hinged doors or windows. The spell storing item can also help. Put continual flame in it to provide free lighting. Use arcane lock to provide security on all gates. Fabricate can be used to create furniture and decorations especially if you have the all-purpose tool. Remember to plan ahead. Have blue prints and a construction plan.
I mean, technically that works, however if you allow the Artificer to import modern knowledge like this then you should also adjust your world building quite a bit. Suddenly every semi-important building will be made of cement since that's something anyone can do, Artificers just can do it better. Not to mention that the PC isn't the only Artificer in the world.
Is the knowledge all that modern? The ancient greeks and romans used cement (with lime) and ancient egyptians used something similar before that.
The "rebar" is probably the most modern feature but even that's not all that recent; metal reinforcements have been used for about as long as concrete has, but it would have been mostly used to connect stone blocks (requiring a lot of cutting/drilling), but I wouldn't be surprised if there were examples of pouring concrete around metal supports around those times, as it would be so much easier than cutting stone, though I guess it depends on their access to lime to make the concrete with?
Take away the limit on volume with magic though and I think it seems a reasonable way to build, so long as you're not using the more modern purpose-made "ribbed" rebar which is the modern invention. If the metal is just for basic joining and/or reinforcement it's fine I think. Plus modern rebar reinforced concrete is partly for strength vs. cost; the bulk of modern concrete is actually a lot weaker than older concrete because it's designed to be "strong enough" but inexpensive, whereas older techniques used higher quality materials which seems to be Cadman02 is suggesting by reshaping solid rock.
The real question for me is whether this method would actually be any easier or faster than the alternatives; a wizard can cast mighty fortress once a week for a year to make a permanent fortress that's reasonably defensible. A purpose built structure can be a lot better than that (as foot-thick walls on a "fortress" is pretty weaksauce), but while using a portable hole for transportation is novel, unless you've got a lot of them it's still going to be pretty slow so I'm not sure it'd actually be a faster way to build a castle (especially not a larger one).
I'm thinking this is better suited less to a castle, and more of heavy duty defences on an existing structure when you only have a short time to prepare; e.g- quickly move blocks from elsewhere, "concrete" it all into a much, much stronger barricade than you could otherwise have made.
For castles at the kind of high-level Artificer player we're talking here it's just going to be more convenient to pay people to build it, so you can be adventuring while they do it to cover the costs.
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The ancients did not use rebar or anything like it. Iron was rare and better used for anything else.
All of their construction was under compression stress so rebar was not needed. Rebar is needed to either keep things under stress so longer distances could be spanned ,modern bridges, or to simply keep concrete that was going to crack together and to stop any further cracking. Like in roads supported by the ground or house foundations.
Cement was mainly used as mortar to protect the blocks of stone or bricks from cracking around their imperfections as they were pressed together over time. Even the great pyramids used a form of mortar.
Some cultures used lead as a locking key to keep large blocks together because they did not use mortar.
The ancients did not use rebar or anything like it. Iron was rare and better used for anything else.
The specifics were different but the principles were the same; metal pinning was often used to aid in building arches, anchor plates can be made from metal and used for structural support, usually on connecting braces and other features to help with constructing larger walls (to prevent bowing), etc.
These weren't widely used because of the access to the materials required, but that's not an issue when we're talking about magical transmutation and a portable hole stocked up with whatever you need.
Concrete likewise wasn't widely available because they wouldn't have had the materials to make enough to use for more than mortar, but with magic it's not an issue because we're not actually talking about concrete anyway, but reshaping stone as if it were concrete.
Point is, similar techniques have existed for long enough that the "too modern" argument doesn't apply; the real limiting factor was access to materials which isn't an issue in a magical setting with the right spells.
And why stop there? Technically you could build basic cars too. Suddenly there are plenty cars in the world because why not? Computers? Not that difficult a concept and if you know how easily doable with some minor magic and tinkering. Welcome to the digital age.
Meant to respond to this earlier, but in a magical setting the question isn't if you could build something similar, it's how; there are automata in D&D, but they don't bother with circuitry when you can simply bind a spirit into a body.
A "car" is really just a self-propelled cart; but are you going to bother developing the combustion engine when you could just enchant the wheels to turn on their own? The people best prepared to do the work to develop new technology in a magical world are usually going to have other ways to do it more easily, so there's little incentive to do it the hard way unless your goal is to make a business out of it, but even then there's probably an easier magical way (e.g- bind the wheel turning spell to a crystal anyone can install into their own cart, teach a load of magical students how to make them, curse them so their arms and legs turn into fish tails if they sell it without giving you your cut…).
This is again why the real question is not if you could do what Cadman02 proposes, especially when "pour rock with metal in it" is not actually new or novel, it's whether there is any real advantage to doing it when there are easier and/or quicker options like just paying other people to do it (probably in around the same time), or use the lesser but much faster mighty fortress and so-on.
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The too modern argument still applies when the world building doesn't include widespread knowledge of these kinds of methods.
Which methods?
As I've already pointed out several times now, concrete and pinning in construction are nothing new, they've been common building practices for several thousands of years; the limiting factor is access to necessary materials to do it at a larger scale.
But we're not talking about gathering the required materials and mixing them up into concrete, we're talking about transmuting rock into mud and then back again, so it's not only an abundant material, it's a superior one, and easier to make if you have the spells to do-so.
The reason it's not a common practice is because your average stonemason can't do this; what they can do is advise a caster on how to do it effectively. But that caster still needs to be of the necessary level, and know the necessary spell(s), and interested in using their spellcasting for a long, complex construction job, which means a vanishingly small number of already somewhat rare casters in most settings. So they're probably either doing it only for themselves, or for an extremely high price, so it's not going to be done everywhere.
Elven cities are usually going to be the most likely to have a large amount of magical construction, but that'd be over the course of centuries, probably with specially trained mages etc. And other than proving that you can do it it may not have any real advantages as it's costly for other reasons.
Literally none of what Cadmon02 is describing is "modern"; he's basically talking about taking a load of stone and turning it into solid walls with magic. 😝
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Yes in real life. However as I already mentioned before, it's not really something you see commonly used in most fantasy settings. We shouldn't judge fantasy settings by real world standards.
Commonly used in what sense? Magical construction exists in loads of fantasy settings, including D&D; most of the time we only encounter it as nicely constructed buildings with no gaps or whatever, what Cadmon02 is describing is just an option for actually making one, or making a traditional building in fewer, stronger pieces.
There are also plenty settings people don't want to see guns while full plate armor is perfectly fine even though guns existed before full plate armor in our world.
They may have existed before proper full plate but they weren't common in reality either. In a fantasy setting it also makes sense they wouldn't be developed when the same people that might do so could just learn magic instead (why faff around with an unreliable powder weapon when you can just hurl a fireball?). On the other hand there are settings where they make sense, e.g- the non-magic users wanted to try to level the playing field a bit.
But we're not talking about firearms, we're talking about basic magical construction which absolutely makes sense to exist in a fantasy setting, and honestly I have no idea why you're so determined to rubbish the idea? It's pretty much a prime example of the kinds of things you can do with these spells.
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It seems you're completely misunderstanding me? I'm not denying the possibility of it existing. I'm denying the idea of the player character doing anything special in that regard. Either it's a sensible thing in the setting so the player character isn't doing anything special, or it isn't a sensible thing in the setting so the player character shouldn't really randomly come up with such an idea because it clearly is player knowledge instead of character knowledge.
You specifically talked about "importing modern knowledge" in your first post, but as I've been pointing out this doesn't rely on modern knowledge so I'm still unclear what you think the player-only knowledge might be here?
What's special is the use of magic, high level magic in the case of the Artificer specifically, the actual basic technique of pouring something into a mould to get the shape you want is not the novel part, so there's no knowledge being imported here. These are all fairly basic uses of the various spells; fabricate to create the moulds more quickly, or get instant furniture, transmute rock to turn rock to mud (so you can manipulate it as mud, like you would manipulate clay to make bricks) then back to rock again.
The only way this would be so special in a setting that the player would be importing knowledge would be if you banned nearly all construction or made the setting prehistoric or something? It's not like Cadman02 is proposing that the castle should be made from graphene nano-materials. 😝
You can basically summarise the core idea as "use big bricks", it's otherwise a description of how you (as an Artificer) could do it. 😉
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Just skip the metal reinforcements and you will be fine.
Wizard construction is a bit iffy though.
Not the creation of the materials but the shear amount spells it would take to make a simple tower. First you have to gather(either by creation or manual digging) the materials then transmute the materials onto your required shapes and one thats all done you have to assemble them into the tower.
Alone this could take years to make a a nice tower with a wall around it.
How about an artifiser creating Congreve rockets? Basically giant bottle rockets with that fireball like explosion at the end. The concept has been around since the 1300's.
An important limiting factor is that few magic users are likely to be high enough level to do more than cast Mold Earth. The ones that are around probably won’t be interested in doing routine construction work for anyone but maybe themselves.
Just considering the cost of getting NPCs to cast higher level spells, the cost to build buildings using mostly magic would be well beyond conventional construction costs. Portable holes are rare, so they should also be extremely expensive and difficult to obtain as well.
So while this magical construction (minus the rebar) might be feasible, it’s probably not something it would make sense for anyone but high end magic users like a PC to consider.
For the original post, why not use Stone Shape. Also on the artificer list and it’s one spell instead of transmute rock and fabricate. Or more realistically just throw it into the mix.
As for concrete, magical construction, etcetera, isn’t that just Eberron?
Concrete as opposed to just lime mortar is actually very old - ancient Egyptian, it may actually be the main core of the great pyramids with the stone blocks being an outer casing and inner chambers construction. The Romans had their special volcanic ash hydraulic cement that they used extensively all over the Roman world. Roman concrete is found from England to Spain to Palestine. Reinforcing ceramics ( concrete is considered a ceramic by engineers) is at least as old - think of the hebrews adding straw to mud brick for Pharaoh before the Exodus. Would it be rare to have an artificer or mage do his for anyone else but themselves? Probably but then the OP wasn’t really talking about doing this commercially, but about the fact that it could be done - and would actually probably be faster and require a much smaller crew. The real problem is that you have to use 40’ cubes not the 64,000 cubic feet that would be the equivalent volume. I believe in older editions it was the volume not the shape but would have to go back into the old PHBs to check. Being able to turn 64,000 cubic feet of rock into mud , then shape it and turn it back into stone would let you build your castle/tower very quickly. Of course you can’t do granite - the spell specifically says you get soft stone - so granite is out but things like limestone, sandstone, marble and shale would work just fine in most cases. In 3e a group of my characters did use these spells to create some buildings very quickly when they needed to.
I am afraid you are wrong about the soft stone. “Transmute Rock to Mud.Nonmagical rock of any sort in the area becomes an equal volume of thick, flowing mud that remains for the spell's duration.” The soft stone part is for the mud to stone part of the spell. I use the stone to mud part and then end it with dispel magic because the other way leaves your castle to vulnerable to being turned into mud with a simple dispel. Rock of any sort means granite works just fine.
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The artificer is a class all about crafting. Not just magic items but ordinary items as well. This includes castles. Thanks to the spell transmute rock you have access to magic cement.
First create a wooden mold with fabricate. Then fabricate a bunch of rebar from junk metal, placing the rebar in the mold. Then fill that mold with rocks of any shape or size. It is best to use the same type of stone and if you want the strongest stone then use granite. When the mold is filled with rocks hit them with transmute rock into mud. Mix the mud together then smooth it out to get a flat top like cement. When it is the way you like it use dispel magic to turn it back into stone. Instead of a bunch of stones you have one big stone ready to be part of a castle. Transmute Rock has an area of effect that is a 40 foot cube so you can get large parts of the castle done in a single day.
This can all be done by one artificer if they have a portable hole and an all-purpose tool. It makes transporting the stone and even placing it very easy depending on what your DM rules on how gravity works in a portable hole. If the gravity of a portable hole matches the outside when open then you could place it on a light 6 foot board and flip it over. You could lift huge blocks of stone and drop it anywhere you like.
Then there is the cantrip mold earth. You can use it to excavate dirt into the portable hole which you then dump else where. You can get the spell with the all-purpose tool for eight hours a day. You can excavate a basement or just a foundation that you create with transmute rock.
Next the spell wall of stone. The transmute rock spell you can create unique shaped stone but if you just need walls then the wall of stone spell is great for fast fabrication of walls. The stone the wall are made of are the same as the stone it comes out of so it should match.
Finally the spell stone shape. Use this spell to do fine detail work like hinged doors or windows. The spell storing item can also help. Put continual flame in it to provide free lighting. Use arcane lock to provide security on all gates. Fabricate can be used to create furniture and decorations especially if you have the all-purpose tool. Remember to plan ahead. Have blue prints and a construction plan.
Is the knowledge all that modern? The ancient greeks and romans used cement (with lime) and ancient egyptians used something similar before that.
The "rebar" is probably the most modern feature but even that's not all that recent; metal reinforcements have been used for about as long as concrete has, but it would have been mostly used to connect stone blocks (requiring a lot of cutting/drilling), but I wouldn't be surprised if there were examples of pouring concrete around metal supports around those times, as it would be so much easier than cutting stone, though I guess it depends on their access to lime to make the concrete with?
Take away the limit on volume with magic though and I think it seems a reasonable way to build, so long as you're not using the more modern purpose-made "ribbed" rebar which is the modern invention. If the metal is just for basic joining and/or reinforcement it's fine I think. Plus modern rebar reinforced concrete is partly for strength vs. cost; the bulk of modern concrete is actually a lot weaker than older concrete because it's designed to be "strong enough" but inexpensive, whereas older techniques used higher quality materials which seems to be Cadman02 is suggesting by reshaping solid rock.
The real question for me is whether this method would actually be any easier or faster than the alternatives; a wizard can cast mighty fortress once a week for a year to make a permanent fortress that's reasonably defensible. A purpose built structure can be a lot better than that (as foot-thick walls on a "fortress" is pretty weaksauce), but while using a portable hole for transportation is novel, unless you've got a lot of them it's still going to be pretty slow so I'm not sure it'd actually be a faster way to build a castle (especially not a larger one).
I'm thinking this is better suited less to a castle, and more of heavy duty defences on an existing structure when you only have a short time to prepare; e.g- quickly move blocks from elsewhere, "concrete" it all into a much, much stronger barricade than you could otherwise have made.
For castles at the kind of high-level Artificer player we're talking here it's just going to be more convenient to pay people to build it, so you can be adventuring while they do it to cover the costs.
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
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The ancients did not use rebar or anything like it. Iron was rare and better used for anything else.
All of their construction was under compression stress so rebar was not needed. Rebar is needed to either keep things under stress so longer distances could be spanned ,modern bridges, or to simply keep concrete that was going to crack together and to stop any further cracking. Like in roads supported by the ground or house foundations.
Cement was mainly used as mortar to protect the blocks of stone or bricks from cracking around their imperfections as they were pressed together over time. Even the great pyramids used a form of mortar.
Some cultures used lead as a locking key to keep large blocks together because they did not use mortar.
The specifics were different but the principles were the same; metal pinning was often used to aid in building arches, anchor plates can be made from metal and used for structural support, usually on connecting braces and other features to help with constructing larger walls (to prevent bowing), etc.
These weren't widely used because of the access to the materials required, but that's not an issue when we're talking about magical transmutation and a portable hole stocked up with whatever you need.
Concrete likewise wasn't widely available because they wouldn't have had the materials to make enough to use for more than mortar, but with magic it's not an issue because we're not actually talking about concrete anyway, but reshaping stone as if it were concrete.
Point is, similar techniques have existed for long enough that the "too modern" argument doesn't apply; the real limiting factor was access to materials which isn't an issue in a magical setting with the right spells.
Meant to respond to this earlier, but in a magical setting the question isn't if you could build something similar, it's how; there are automata in D&D, but they don't bother with circuitry when you can simply bind a spirit into a body.
A "car" is really just a self-propelled cart; but are you going to bother developing the combustion engine when you could just enchant the wheels to turn on their own? The people best prepared to do the work to develop new technology in a magical world are usually going to have other ways to do it more easily, so there's little incentive to do it the hard way unless your goal is to make a business out of it, but even then there's probably an easier magical way (e.g- bind the wheel turning spell to a crystal anyone can install into their own cart, teach a load of magical students how to make them, curse them so their arms and legs turn into fish tails if they sell it without giving you your cut…).
This is again why the real question is not if you could do what Cadman02 proposes, especially when "pour rock with metal in it" is not actually new or novel, it's whether there is any real advantage to doing it when there are easier and/or quicker options like just paying other people to do it (probably in around the same time), or use the lesser but much faster mighty fortress and so-on.
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Which methods?
As I've already pointed out several times now, concrete and pinning in construction are nothing new, they've been common building practices for several thousands of years; the limiting factor is access to necessary materials to do it at a larger scale.
But we're not talking about gathering the required materials and mixing them up into concrete, we're talking about transmuting rock into mud and then back again, so it's not only an abundant material, it's a superior one, and easier to make if you have the spells to do-so.
The reason it's not a common practice is because your average stonemason can't do this; what they can do is advise a caster on how to do it effectively. But that caster still needs to be of the necessary level, and know the necessary spell(s), and interested in using their spellcasting for a long, complex construction job, which means a vanishingly small number of already somewhat rare casters in most settings. So they're probably either doing it only for themselves, or for an extremely high price, so it's not going to be done everywhere.
Elven cities are usually going to be the most likely to have a large amount of magical construction, but that'd be over the course of centuries, probably with specially trained mages etc. And other than proving that you can do it it may not have any real advantages as it's costly for other reasons.
Literally none of what Cadmon02 is describing is "modern"; he's basically talking about taking a load of stone and turning it into solid walls with magic. 😝
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
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Commonly used in what sense? Magical construction exists in loads of fantasy settings, including D&D; most of the time we only encounter it as nicely constructed buildings with no gaps or whatever, what Cadmon02 is describing is just an option for actually making one, or making a traditional building in fewer, stronger pieces.
They may have existed before proper full plate but they weren't common in reality either. In a fantasy setting it also makes sense they wouldn't be developed when the same people that might do so could just learn magic instead (why faff around with an unreliable powder weapon when you can just hurl a fireball?). On the other hand there are settings where they make sense, e.g- the non-magic users wanted to try to level the playing field a bit.
But we're not talking about firearms, we're talking about basic magical construction which absolutely makes sense to exist in a fantasy setting, and honestly I have no idea why you're so determined to rubbish the idea? It's pretty much a prime example of the kinds of things you can do with these spells.
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
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You specifically talked about "importing modern knowledge" in your first post, but as I've been pointing out this doesn't rely on modern knowledge so I'm still unclear what you think the player-only knowledge might be here?
What's special is the use of magic, high level magic in the case of the Artificer specifically, the actual basic technique of pouring something into a mould to get the shape you want is not the novel part, so there's no knowledge being imported here. These are all fairly basic uses of the various spells; fabricate to create the moulds more quickly, or get instant furniture, transmute rock to turn rock to mud (so you can manipulate it as mud, like you would manipulate clay to make bricks) then back to rock again.
The only way this would be so special in a setting that the player would be importing knowledge would be if you banned nearly all construction or made the setting prehistoric or something? It's not like Cadman02 is proposing that the castle should be made from graphene nano-materials. 😝
You can basically summarise the core idea as "use big bricks", it's otherwise a description of how you (as an Artificer) could do it. 😉
Former D&D Beyond Customer of six years: With the axing of piecemeal purchasing, lack of meaningful development, and toxic moderation the site isn't worth paying for anymore. I remain a free user only until my groups are done migrating from DDB, and if necessary D&D, after which I'm done. There are better systems owned by better companies out there.
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Just skip the metal reinforcements and you will be fine.
Wizard construction is a bit iffy though.
Not the creation of the materials but the shear amount spells it would take to make a simple tower. First you have to gather(either by creation or manual digging) the materials then transmute the materials onto your required shapes and one thats all done you have to assemble them into the tower.
Alone this could take years to make a a nice tower with a wall around it.
How about an artifiser creating Congreve rockets? Basically giant bottle rockets with that fireball like explosion at the end. The concept has been around since the 1300's.
An important limiting factor is that few magic users are likely to be high enough level to do more than cast Mold Earth. The ones that are around probably won’t be interested in doing routine construction work for anyone but maybe themselves.
Just considering the cost of getting NPCs to cast higher level spells, the cost to build buildings using mostly magic would be well beyond conventional construction costs. Portable holes are rare, so they should also be extremely expensive and difficult to obtain as well.
So while this magical construction (minus the rebar) might be feasible, it’s probably not something it would make sense for anyone but high end magic users like a PC to consider.
For the original post, why not use Stone Shape. Also on the artificer list and it’s one spell instead of transmute rock and fabricate. Or more realistically just throw it into the mix.
As for concrete, magical construction, etcetera, isn’t that just Eberron?
Concrete as opposed to just lime mortar is actually very old - ancient Egyptian, it may actually be the main core of the great pyramids with the stone blocks being an outer casing and inner chambers construction. The Romans had their special volcanic ash hydraulic cement that they used extensively all over the Roman world. Roman concrete is found from England to Spain to Palestine. Reinforcing ceramics ( concrete is considered a ceramic by engineers) is at least as old - think of the hebrews adding straw to mud brick for Pharaoh before the Exodus. Would it be rare to have an artificer or mage do his for anyone else but themselves? Probably but then the OP wasn’t really talking about doing this commercially, but about the fact that it could be done - and would actually probably be faster and require a much smaller crew. The real problem is that you have to use 40’ cubes not the 64,000 cubic feet that would be the equivalent volume. I believe in older editions it was the volume not the shape but would have to go back into the old PHBs to check. Being able to turn 64,000 cubic feet of rock into mud , then shape it and turn it back into stone would let you build your castle/tower very quickly. Of course you can’t do granite - the spell specifically says you get soft stone - so granite is out but things like limestone, sandstone, marble and shale would work just fine in most cases. In 3e a group of my characters did use these spells to create some buildings very quickly when they needed to.
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I am afraid you are wrong about the soft stone. “Transmute Rock to Mud.Nonmagical rock of any sort in the area becomes an equal volume of thick, flowing mud that remains for the spell's duration.”
The soft stone part is for the mud to stone part of the spell. I use the stone to mud part and then end it with dispel magic because the other way leaves your castle to vulnerable to being turned into mud with a simple dispel. Rock of any sort means granite works just fine.