Buildings:

I based everything on a cost/square foot figure for each building type and material, and expressed upgrades as additional costs. You must calculate costs for each story of the building separately and then add them together.

Simple One Room Hovel

(assuming 25’X25′, or 625 sqft)

Cost is .5gp/sqft

This gets you a wooden, poorly framed structure (no interior walls), a thatched roof, clay floor, simple shallow foundation, and a small and simple hearth for 312.5gp

Upgrades:

Wooden Plank Flooring: additional .25gp/sqft, for 468.75gp

Earthen Root Cellar (also includes the necessary Plank Floor): +.5gp/sqft, for 625gp.

Plank or Wooden Shingle Roof: +1gp/sqft, for 937.5gp

Simple House through Grand House

I assumed a 25’X40’=1000sqft Simple House (1-3 rooms), and a 50’X100’=5000sqft Grand House (4-10 rooms). These two structures are described as having wooden structures and thatched roofs.

Cost is 1gp/sqft

Upgrades:

Plank or Wooden Shingle Roof: +1gp/sqft

Clay Tile Roof: +2gp/sqft

Slate Roof: +3gp/sqft

Copper Roof: +4gp/sqft

Brick Structure: +5gp/sqft

Stone Structure: +6gp/sqft

To accurately re-create the DMG Simple House:

25’X40′, or 1000sqft– This gets you a wooden structure (with interior walls), thatched roof, plank floor, adequate hearth(s) and a foundation, with a cellar for 1000gp.

To accurately re-create the DMG Grand House:

50’X100′, or 5000sqft– This gets you a wooden structure (with interior walls), thatched roof, plank floor, adequate hearth(s) and a foundation, with a cellar for 5000gp.

Mansion

I assumed a 50’X100′ 2-story, 10000sqft Mansion (10-20 rooms), which is said to have a wooden and brick structure and a slate roof.

Use above costs, and multiply by X2 due to quality of craftsmanship

To accurately re-create the DMG Mansion:

50’X100′, 2-story, or 10,000sqft– 5000sqft 1st Floor= 5000X6gp (1gp base+5gp for Brick)=30,000gp 5000sqft 2nd Floor= 5000X4gp (1gp base+3gp for Slate Roof)= 20,000gp

50,000gp X2 for Mansion multiplier = 100,000gp

Towers, Keeps, Castles

For Towers, Keeps, Castles, etc., I haven’t been able to extrapolate anything clean to use as a base yet, so I would suggest to just use the prices for those as listed (50,000gp for a tower, etc.)

Building Costs

[1 Man Hour X (GP Value of Structure/10)] X Luxury Factor*

Such as X2 for a Mansion

So, a 1000 sqft Simple House with no upgrades would take 1000 Man Hours… so a 20 man crew could build it in 5 10-hours days. Sven’s House would take 1600 Man Hours, or a 20 man crew 8 10-hour days. A 100,000 Mansion would take 20,000 Man Hours, or 50 men 40 10-hour days.

Example

To recreate an example of Sven’s house, which went for 16,000gp

Small, well built house, 25’X40′, 2-stories (both stone) with a slate roof, wood plank floors, hearths, and a cellar, 2000sqft–

1000sqft 1st floor, 1000X7 (1gp base + 6gp for Stone)= 7000gp

1000sqft 2nd floor, 1000X10 (1gp base + 6gp Stone and 3gp for Slate Roof)= 10,000

7000+10000= 17,000gp (Since its in the Mudsitters District, across from the Blackrazor Guild, it went for 16,000gp )