Home Additions in Olney
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.
Start your Olney home additions with a written scope
Tell us the two things we need to call you back — a project manager rings you to book the free walkthrough. We work Brookeville, Sandy Spring, Ashton and every Olney ZIP: 20832, 20833.
- A written, line-item scope for your Olney project before anyone swings a hammer
- Permits pulled through the Montgomery County Department of Permitting Services under MHIC #111971
- One project manager from demolition to final walkthrough
Two fields and one question. A specialist calls you back to confirm a time.
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 Olney 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.
Olney sits at the edge of Montgomery County's water and sewer envelope, and properties beyond it are on well and septic. If your project adds a bedroom — a basement bedroom or an addition — septic capacity can govern whether it is permittable at all, since systems are sized by bedroom count. Parcels bordering the county's Agricultural Reserve also carry their own zoning constraints on what can be built.
The house decides half the scope.
Olney is mostly later-20th-century subdivision housing on generous lots, and most of those neighborhoods have an HOA with architectural review for exterior work.
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
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.
Financing is available — most homeowners spread a project this size over monthly payments rather than paying cash up front.
Free Olney walkthrough
A written, line-item scope for your home additions project. No design fee, no obligation.
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Alex helped me with the estimate, paperwork, schedule, and insurance claim. We were very satisfied with the quality of the roofing replacement and the timeline. They were prompt throughout.
139 reviews at 4.9 stars across Google, and most of them are for our roofing and exterior work — that is the business we started in. The crew, the licences and the paperwork are the same ones now carrying home additions projects. Read all our reviews →
One contractor for the rest of the house
Our Olney crews cover Brookeville, Sandy Spring, Ashton, Rockville and every ZIP in the area — 20832, 20833.
Straight answers
Do you handle home additions in Olney, MD?
Yes. United Developers is a licensed contractor in Maryland (MHIC #111971) and works throughout Olney and Montgomery County, including 20832, 20833 and nearby Brookeville, Sandy Spring, Ashton.
Who pulls the permit for a Olney 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.
What should I expect in a Olney home?
Olney is mostly later-20th-century subdivision housing on generous lots, and most of those neighborhoods have an HOA with architectural review for exterior work.
What does home additions cost in Olney?
Most Olney 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 Olney 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.