ADU Construction in Bethesda, MD — Accessory Dwelling Unit Contractor
What Is an ADU? (Accessory Dwelling Unit)
An Accessory Dwelling Unit (ADU) — also called an in-law suite, granny flat, carriage house, or backyard cottage — is a secondary residential unit built on the same lot as a primary single-family home. ADUs are fully self-contained living spaces with their own bedroom, bathroom, and kitchen or kitchenette.
In Bethesda and throughout Montgomery County, ADUs are legal under the county's updated ADU ordinance and are growing in popularity among homeowners who want to generate rental income, house aging parents or adult children, or add significant value to their property.
💡 Bethesda ADU Opportunity: With its proximity to Washington DC, NIH, Walter Reed, and major corporate employers, Bethesda has one of the strongest ADU rental markets in Maryland — long-term rental demand is high and vacancy rates are low.
Types of ADUs We Build in Bethesda, MD
DMV General Contracting Group builds all types of ADUs in Bethesda and Montgomery County. Here are the four main ADU types we specialize in, along with typical cost ranges for the Bethesda market:
Detached ADU (Backyard Cottage)
A brand-new, standalone structure built in your backyard — separate from the main house. Full kitchen, bathroom, bedroom, and private entrance. Maximum privacy for tenants or family members.
Basement ADU Conversion
Convert your existing unfinished basement into a fully legal, permitted apartment. Includes egress window, kitchenette, full bath, bedroom, and separate entrance. Lowest cost per square foot.
Garage Conversion ADU
Transform an attached or detached garage into a comfortable, legal living space. We handle insulation, HVAC, plumbing rough-in, flooring, and all finishes while maintaining curb appeal.
Attached In-Law Suite Addition
A new addition built onto your existing home — sharing a wall but with a completely separate entrance, living area, kitchen, and bathroom. Ideal for multigenerational living in Bethesda.
Benefits of Building an ADU on Your Bethesda Property
Bethesda homeowners are increasingly turning to ADUs as one of the smartest investments they can make in their property. Here's why:
ADU Zoning Rules in Bethesda & Montgomery County, MD
One of the most important parts of building an ADU in Bethesda is understanding Montgomery County's zoning requirements. DMV General Contracting Group's in-house architects and permit team are experts in local ADU regulations and handle the entire approval process for you. Here's a summary of the key rules:
Montgomery County ADU Zoning Quick Reference
ADU Construction Cost in Bethesda, MD
Here is a detailed breakdown of ADU construction costs in Bethesda, Maryland. These ranges reflect the Bethesda/Montgomery County market, where labor, material, and permit costs are higher than national averages:
| ADU Type | Typical Cost Range | Timeline | Notes |
|---|---|---|---|
| Basement ADU Conversion | $75,000 – $130,000 | 3–5 months | Lowest cost option; uses existing foundation & structure |
| Garage Conversion ADU | $60,000 – $120,000 | 3–4 months | Cost varies based on attached vs detached garage |
| Attached In-Law Suite Addition | $100,000 – $220,000 | 5–8 months | New addition built onto existing home structure |
| Detached ADU (New Build) | $150,000 – $300,000+ | 6–10 months | Full new construction on your lot; highest cost & value |
These costs include architectural design, all Montgomery County permit fees, full construction, and final inspections. In Bethesda's real estate market, a detached ADU can add $200,000–$300,000+ to your property value — making the investment highly favorable for most homeowners.
Why Choose DMV General Contracting Group for Your Bethesda ADU Project
Building an ADU in Bethesda is more complex than a standard remodeling project. It involves zoning review, architectural design, structural engineering, multiple permit types, and coordination of all trades. You need a contractor with real ADU experience — not one learning on your project.
DMV General Contracting Group is one of the few contractors in the Bethesda area that offers true design-build ADU services — meaning our architects design your unit, our engineers approve the structure, our permit team files all paperwork, and our licensed crews build it. One team, one contract, complete accountability.
Our ADU Construction Process in Bethesda
Here is exactly how DMV General Contracting Group manages your ADU project in Bethesda from first conversation to move-in ready:
Free Feasibility Consultation & Site Visit
We visit your Bethesda property, review your lot size and zoning classification, assess existing structures (basement, garage), and determine which ADU types are feasible — at no charge.
Architectural Design & 3D Renderings
Our in-house architects design your ADU floor plan, elevations, and 3D renderings. You review and approve the design before any permits are filed. We refine until you're completely satisfied.
Montgomery County Zoning & Permit Processing
We submit all required zoning applications and building, electrical, plumbing, and mechanical permits to Montgomery County on your behalf. We manage all back-and-forth with the county reviewers.
Site Prep & Foundation (Detached ADUs)
For new detached ADUs, we handle site grading, utility connections, and foundation work before vertical construction begins. All work is inspected and approved by Montgomery County at each phase.
Full Construction — Framing Through Finishes
Our licensed crews handle all construction phases: structural framing, roofing, insulation, drywall, flooring, electrical, plumbing, HVAC, cabinetry, tile, fixtures, and all interior and exterior finishes.
Final Inspections & Certificate of Occupancy
We schedule and manage all required Montgomery County final inspections. Upon passing all inspections, you receive a Certificate of Occupancy — making your ADU fully legal to rent or occupy.
ADU vs. Home Addition — What's Right for Your Bethesda Home?
Bethesda homeowners sometimes ask whether they should build an ADU or do a traditional home addition. The key difference is independence: an ADU is a fully separate, self-contained dwelling unit with its own entrance, kitchen, and bathroom — it can be rented or occupied independently. A home addition simply expands the primary home's square footage without creating a separate living unit.
If your goal is rental income, housing a family member independently, or maximizing long-term property value, an ADU is the better investment. If your goal is simply more space within your existing home, a home addition or room expansion may be more appropriate. DMV General Contracting Group builds both — and can help you determine which option makes more sense for your specific Bethesda property during your free consultation.
Serving Bethesda and Surrounding Areas for ADU Construction
In addition to ADU construction in Bethesda, MD, our licensed team serves homeowners throughout Montgomery County and the greater DMV area:
ADU construction in Chevy Chase & Potomac, MD
Chevy Chase and Potomac are among the most popular areas for ADU construction near Bethesda — large lots, high property values, and strong rental demand make ADUs an especially attractive investment. DMV General Contracting Group regularly builds ADUs across both communities and is fully familiar with their specific Montgomery County zoning conditions.
ADU construction in Washington DC
DMV General Contracting Group holds both a Maryland MHIC license and a Washington DC DLCP license. We build ADUs on both sides of the border — whether your property is in Bethesda or DC neighborhoods like Chevy Chase DC, Friendship Heights, or Tenleytown, our team can help.
Frequently Asked Questions — ADU Construction in Bethesda, MD
Explore Our Other Services in Bethesda
Beyond ADU construction, DMV General Contracting Group offers a full range of home remodeling and addition services across Bethesda and the DMV area:
