Montgomery County · MD

Home Additions in Potomac

An addition is the one project where zoning can stop you before design starts. We are a licensed contractor in Maryland (MHIC #111971) — we pull the permits through the Montgomery County Department of Permitting Services, coordinate the licensed trades, and hand you a written line-item scope before demolition starts.

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Permits & inspections in Montgomery County

The paperwork is the part most contractors gloss over.

An addition starts with zoning, not construction: setbacks, lot coverage and height limits get reviewed before a building permit is issued, and in some neighborhoods there is a stormwater or historic review on top. Then come the footing and foundation inspections, which have to pass before backfill. This is the longest-lead permit of any project we do, and it is why we start the paperwork while the design is still being drawn.

Your Potomac permit goes through the Montgomery County Department of Permitting Services. We pull it under our license and we hold the inspection schedule — you do not chase inspectors and you do not sign the application.

Local to Potomac

A lot of Potomac sits outside Montgomery County's public water and sewer envelope, which means well and septic. That matters more than homeowners expect: adding a bedroom — in an addition or a finished basement — can require a septic capacity review before the county will permit it, because bedroom count is how septic systems are sized. On a large-lot Potomac property this is the first thing to check, not the last.

What we find in Potomac homes

The house decides half the scope.

Potomac is large-lot housing — much of it 1960s–1980s with substantial later renovation, plus newer custom construction. Many neighborhoods also carry HOA covenants requiring architectural approval for exterior changes, which runs on a separate track from the county permit.

What's included
  • Zoning, setback and lot-coverage review before design is finalized
  • Footings placed below the regional frost line
  • Footing and foundation inspections passed before backfill
  • Roofline, siding and HVAC tied into the existing house so it does not read as an add-on
Planning range — Montgomery County
$180 – $340 / sq ft

A planning range, not a quote. Your written line-item price comes after a free on-site walkthrough. HVAC, electrical and plumbing are performed by licensed trade partners.

20854BethesdaNorth PotomacRockvilleCabin John

Free Potomac walkthrough

A written, line-item scope for your home additions project. No design fee, no obligation.

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Also in Potomac

One contractor for the rest of the house

Our Potomac crews cover Bethesda, North Potomac, Rockville, Cabin John and every ZIP in the area — 20854.

Potomac home additions questions

Straight answers

Do you handle home additions in Potomac, MD?

Yes. United Developers is a licensed contractor in Maryland (MHIC #111971) and works throughout Potomac and Montgomery County, including 20854 and nearby Bethesda, North Potomac, Rockville.

Who pulls the permit for a Potomac home additions project?

We do, under our license, through the Montgomery County Department of Permitting Services. An addition starts with zoning, not construction: setbacks, lot coverage and height limits get reviewed before a building permit is issued, and in some neighborhoods there is a stormwater or historic review on top. Then come the footing and foundation inspections, which have to pass before backfill. This is the longest-lead permit of any project we do, and it is why we start the paperwork while the design is still being drawn.

Is there anything specific to Potomac I should know?

A lot of Potomac sits outside Montgomery County's public water and sewer envelope, which means well and septic. That matters more than homeowners expect: adding a bedroom — in an addition or a finished basement — can require a septic capacity review before the county will permit it, because bedroom count is how septic systems are sized. On a large-lot Potomac property this is the first thing to check, not the last.

What does home additions cost in Potomac?

Most Potomac projects land in the $180 – $340 / sq ft range. That is a planning range for Montgomery County, not a quote — your written price comes after a free on-site walkthrough.

Is the Potomac walkthrough and estimate free?

Yes. The walkthrough and the written scope are free and yours to keep whether or not you hire us. There is no design fee and no consultation invoice.

How long does an addition actually take?

The build is rarely the long part — permitting and zoning review are. Expect the approval phase to run in parallel with final design, and expect us to give you a schedule that names the permit milestone rather than hiding it. We will tell you at the walkthrough if your lot has a setback or coverage problem, because that changes the whole conversation.

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