Getting Started

Blackreach Refuge is accessible from Blackreach, in the lake near the Derelict Pumphouse and below the Raldbthar Deep Market.  To get in, you need the Initiate's Ewer from the main quest of the Dawnguard DLC.  If you've lost it or don't want to go to the trouble of getting it, you can add one to your inventory via the console:
player.additem 0200a89e 1
If this command doesn't work, use the ID that this command gives you for the item instead of 0200a89e with player.additem:
help "Initiate's Ewer"

With the ewer in your inventory, activate the altar in the outer room.  This should open the door to the main area.  Alternately, if you'd like to permanently remove the altar doors, open the console, click on an altar door to target it, and type disable.  If the wrong thing disappears, type enable to bring it back and try again.

There's an optional file that makes the ewer weightless, available as an ESL or ESP; may conflict with any mod that directly edits the ewer.  Patches are also available to hide map markers for the wayshrine exits, resize one tree if you have Simply Bigger Trees, and add a few aquariums for Creation Club Fishing.

The most current version of the main file is 3.0.  Older versions are still available for download.


Building (and how to skip it)

As of the 2.0 version, the home is now buildable (using this resource by OrinLinwe-- thanks!).  When you first enter, you'll find empty rooms with a few rubble piles.  Activating rubble piles cleans them up and places toolkits that allow you to construct various portions of the home, similar to the houses in the Hearthfire expansion.  The script that enables the new furniture also makes a few hours pass, so if you use a needs mod or similar based on in-game time, please give the game a little time to catch up in between activating workbenches and rubble piles.

Wayshrines, which let you fast-travel to near major cities, also need to be activated with a filled petty soul gem before they can be used.

If you'd rather not gather resources to build the home, I've put a chest with all the necessary resources under the altar in the outer room.  Simply tcl through the floor, grab everything, and then activate the rubble and workstations to build each part.  There is also a spare copy of the Initiate's Ewer in the chest.


Details

Once built, the home includes all major crafting stations; the main room will contain a forge, smelter, workbench, grinder, tanning rack, cooking pot, Hearthfire oven, enchanting table, and alchemy lab.  In the back room, there's a wood chopping block and flour grinder which didn't fit nicely in the main room.  All storage containers in the house are safe.

There are more than enough planters in the house to grow everything that is plantable in the base game.  There are soil patches in the bedroom area to the left of the main room and several other themed areas in the back room, including a Solstheim-like area.

The back room also has a fish hatchery.  This functions sort of similarly to the Hearthfire hatchery; it's set up as two containers, "stock" and "harvest".  You can place any fish or fish eggs you find in the world into the "stock" container, and if there are two or more they'll breed gradually and you can pick up other fish or fish products of that kind from the "harvest" container after a few days.  You can also drop more into the "stock" container to increase the chance and amount of that kind of fish being produced, up to six of each item.  An optional patch is available to let you add fish from Fishing as well.

If you don't like any clutter or items, you can safely get rid of them by selecting them in the console and using disable.

The wayshrine in the house connects to a network of wayshrines that can let you out near major cities.  The house wayshrine connects directly to a wayshrine near the Nightgate Inn ("Central Wayshrine").  That wayshrine also connects to ones near Whiterun and Dawnstar as well as two others: "Eastern Wayshrine", which connects to Winterhold, Windhelm, Riften, and Ivarstead; and "Western Wayshrine", which connects to Solitude, Markarth, Falkreath, and Morthal.  All wayshrine portals are two-way.

Wayshrine exits are largely placed in unobtrusive places (moved as of 2.0); the intent was to make it more logical that nobody has stumbled on the location except you.  Some are underwater.  Others are wedged into corners.  This does mean that it may be difficult to get followers through these entrances.  This mod was made primarily for personal use, and I don't generally use followers, so I haven't tested it extensively.


Technical and Troubleshooting

This mod contains an ESP and some script, texture, and mesh resources.  Just add these to your mod manager (or data folder, if you like to live dangerously) as you would any other mod.  Load order shouldn't be especially important.  If another mod edits a cell that contains one of the wayshrine exits, you might see clipping or other issues; let me know if this happens and I can look at making a patch.

The base game and DLCs are required due to resources used.

If you have trouble finding the entrance, try warping there with the console:
coc aaVYSBlackreachRefugeExterior

If this command does nothing, it's likely you haven't installed the mod correctly.  Try reinstalling.  If the problem persists, there may be a conflict with another mod editing the area; load the mod later and see if the entrance shows up.  In this case leave a comment with the other mod and I'll see about making a patch.

Interiors are navmeshed.  As this is my first try at doing so, please let me know if you see any funky NPC behavior and I'll go in and see if I can fix it.


Credits

Build a home PDF Scripts Meshes by OrinLinwe
Dwemer clutter and wooden dividers by Insanity
DLC Colored Lanterns by SpectralDragon
Lanterns by Phitt
Creature Pack by Vicn

Thanks!