Looking for an addition contractor in Keystone, SD? Describe your project once and up to three addition contractors who work in Keystone and Pennington County get back to you with a quote. It's free and there is no obligation.
Keystone is home to about 261 people (2024 Census Bureau estimate), a growing community (+7.4% since 2020). With 87 people per sq mi, it is a rural area. Growing families here often add space instead of moving.
Keystone at a glance
- Population (Census Bureau estimate, 2024)
- 261 (+7.4% since 2020)
- Rank in South Dakota
- 162nd of 310 cities and towns
- Land area
- 3.0 sq mi
- Population density
- 87 people per sq mi (rural)
- Type
- Town (Keystone town)
- Main county
- Pennington County
What to check before hiring in Keystone
- Zoning: check Keystone's setbacks, lot coverage and height limits first.
- License and permit: in South Dakota, additions are built by licensed contractors under a permit.
- Structure: second stories need an engineer to check the existing house.
- Price drivers: size, foundation, roof tie-in, plumbing and finishes.
Useful official resources
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ICC: International Code Council
Official information and guidance.
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NAHB
Official information and guidance.
Services available in Keystone
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Room addition
Ground-floor addition with foundation, framing, roof and finishes.
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Second-story addition
New floor over the existing house, with structural engineering.
Frequently asked questions in Keystone
How much does an addition cost in Keystone, SD?
It depends on size, foundation and finishes. Describe your project: contractors who serve Keystone reply with a quote.
How long does it take?
Often a few months, plus design and permits.
Does an addition raise property taxes?
Usually, since it increases the assessed value.
Which addition contractors will contact me?
Up to three independent addition contractors who serve Keystone and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.