Serving Central Texas
ADU Construction in San Marcos, Texas, Done Right the First Time
Bayside Home Builders designs and builds accessory dwelling units in San Marcos from permitted plans through final inspection, so you get a legal, livable space without the runaround.
adu project · San MarcosSan Marcos Lots Are Not All ADU-Ready, and Most Contractors Will Not Tell You That Until After You Sign
San Marcos is one of the fastest-growing cities in Texas. That growth means more homeowners are looking at ADUs to add rental income or house family members. It also means a lot of contractors are taking deposits before doing serious due diligence on whether your specific lot can actually support the ADU you want.
What you are living with
You end up waiting. Waiting on a permit review that stalls because setbacks were not checked. Waiting on a redesign because the original plan did not account for your utility easement. Waiting on a contractor who submitted incomplete documents and is now juggling three other jobs. In a city where the permitting office is processing more ADU applications than ever, a sloppy submittal goes to the back of the line.
What you get instead
We visit your lot before we draw anything. We check setbacks, utility connection points, drainage, and whether your existing structure affects placement. Then we give you a realistic scope and a real number, not a range so wide it is meaningless. If your lot has a problem, you will know before you spend a dollar on design.
Our Recent Work
Accessory Dwelling Units Built to Code, Built to Last
An ADU adds livable square footage to your property without buying a new lot. Whether you need a rentable unit, a guest suite, or a place for family, we handle the full project from permit drawings to final walkthrough.
Permit-Ready Design and Drawings
We produce the architectural drawings your local building department requires, sized and formatted to meet current zoning and setback rules for your property. You do not have to coordinate a separate architect.
Foundation and Structural Work
Detached ADUs get a properly engineered foundation matched to your soil conditions. Garage conversions and attached units get any required structural reinforcement so the finished space meets code for habitable square footage.
Full Mechanical, Electrical, and Plumbing Rough-In
We rough in all systems, coordinate inspections at each required phase, and use licensed trade partners for electrical and plumbing so every system is signed off before walls close.
Insulation and Energy Compliance
ADUs must meet the same energy codes as a primary residence. We install insulation, windows, and HVAC equipment that pass inspection and keep utility bills reasonable for whoever lives in the space.
Interior Finishes and Kitchen or Kitchenette
Flooring, cabinetry, countertops, fixtures, and trim are all included in our scope. We work from a finish schedule you approve before construction starts so there are no surprises at the end.
Site Work and Utility Connections
We coordinate water, sewer, and electrical tie-ins to the existing property service, handle any required utility upgrades, and restore disturbed landscaping so the finished ADU looks intentional, not tacked on.
Why Homeowners Choose Bayside for Their ADU
ADUs involve zoning research, permit coordination, and trade scheduling that most remodelers are not set up to handle well. Here is what we actually bring to the project.
We Pull the Permit, Period
We do not hand you a permit application and wish you luck. Our team prepares the drawings, submits to the building department, responds to plan review comments, and tracks the approval through to issuance. You stay informed without having to manage the process yourself.
Design-Build Under One Roof
Design and construction are handled by the same company, so the drawings we produce are priced by the crew that builds them. There is no gap between what the designer planned and what the builder can actually execute or afford to include.
Over 500 Projects Completed, Insured and Bonded
We carry full general liability insurance and are bonded on every project. With more than 500 completed projects behind us, we have encountered and solved the structural surprises, utility conflicts, and zoning edge cases that come up on real properties.
Fixed Scope Before We Break Ground
We do not start construction on a vague allowance budget. Before any work begins, you have a signed contract with a defined scope, a finish schedule you reviewed, and a timeline that accounts for permit lead time. Change orders happen when the scope changes, not because we underquoted to win the job.
How an ADU Project Works with Bayside
Most homeowners have never built an ADU before. Here is the straight sequence from your first call to handing you the keys.
Step 1: Site and Zoning Review
We start by reviewing your property, lot dimensions, existing structures, and local zoning rules to confirm what you can build and where. This step identifies setback requirements, size limits, utility connection points, and any restrictions that affect your options before you spend anything on design.
Step 2: Design, Pricing, and Contract
We develop a floor plan and scope of work based on what your site allows and what you need the space to do. You review the drawings, the finish schedule, and the project cost before signing. Nothing moves to permit submittal until you have approved the full plan.
Step 3: Permitting and Pre-Construction
We submit your permit package, respond to any plan review comments, and schedule trade partners once approval is in hand. Permit timelines vary by jurisdiction, and we set your expectations at the start based on current local lead times so the wait is not a surprise.
Step 4: Construction, Inspections, and Closeout
We build to the approved plans, schedule each required inspection, and do not close up walls until the rough-in phases are signed off. At completion, we walk the project with you, address any punch-list items, and hand you the final certificate of occupancy so the unit is legally habitable.
ADU Contractors Serving San Marcos, Texas
San Marcos sits between Austin and San Antonio, and its housing stock reflects that growth pressure. Lots are varied, city regulations are specific, and getting an ADU built right the first time saves you months of back-and-forth with the city. We handle design, permitting, and construction so you are dealing with one team from start to finish.
Permits & review
San Marcos has its own ADU regulations published through the city at sanmarcostx.gov. Detached ADUs are permitted on single-family lots, and the city has posted an Accessory Dwelling Unit guide online to help homeowners understand the process. Size limits, setbacks, and utility connection requirements all apply, and the city reviews each project individually. We pull your permit, handle the submittals, and coordinate inspections so you are not managing that process yourself.
Housing stock
San Marcos has a mix of older in-town lots, newer suburban subdivisions, and properties on larger parcels further from the core. Older lots can have drainage, setback, or utility access issues that affect where an ADU can sit and what it will cost to connect. We assess your specific lot before we quote anything, because what works on one property in San Marcos may not work on the lot next door.
Areas we serve
We serve San Marcos and the surrounding Central Texas corridor, including Kyle, Buda, Wimberley, and New Braunfels. If you are in Hays County or Comal County and want to add a guest house, rental unit, or in-law suite, we can evaluate your site and walk you through what is realistic for your property and budget.
Common questions
What does it cost to build an ADU in San Marcos, Texas?
For a detached ADU in San Marcos, TX, budget roughly $130 to $220 per square foot for construction, depending on finishes, site conditions, and utility connections. A basic 600 square foot unit with standard finishes typically runs $80,000 to $120,000 all in. Add a full kitchen, upgraded baths, or a difficult lot and the number climbs. Any contractor quoting you a firm price before seeing your property and reviewing city requirements is guessing.
What size ADU can I build on my San Marcos, Texas lot?
San Marcos, Texas follows state law, which generally allows a detached ADU up to 1,200 square feet on a single-family lot, subject to setbacks, lot coverage limits, and your specific zoning district. The City of San Marcos has published an ADU guide at sanmarcostx.gov that outlines local rules. We pull the zoning details on your parcel before design starts so there are no surprises at permit submission.
How long does it take to build an ADU in San Marcos?
From signed contract to certificate of occupancy, plan on 6 to 12 months for a detached ADU in San Marcos. Design and permit review typically takes 2 to 4 months depending on city workload and any revision requests. Construction on a straightforward detached unit runs 3 to 5 months after permit approval. Rushed timelines and contractors who promise less are usually not accounting for city review cycles.
Do I need a permit to build an ADU in San Marcos, Texas?
Yes, every ADU in San Marcos requires a building permit through the City of San Marcos Development Services. You will need approved construction drawings, and the project must pass inspections for foundation, framing, mechanical, electrical, plumbing, and final occupancy. Unpermitted ADUs create serious title and insurance problems when you sell. We handle the full permit package and manage the inspection schedule.
What are the real drawbacks of building an ADU?
Honest answer: upfront cost is significant, utility hookup fees in Central Texas can add $10,000 to $25,000 depending on what is on the property, and city permitting takes time. If you have a septic system, adding a second dwelling may require an upgraded system, which adds cost. ADUs also add square footage that affects your property tax assessment. That said, rental income in the San Marcos market, driven in part by Texas State University enrollment, can offset those costs over time. We walk through all of this before you commit.
Can I use a pre-approved ADU plan in San Marcos, Texas?
The City of San Marcos, TX does not currently operate a permit-ready ADU plan library the way some larger cities do. You will need a set of drawings prepared and stamped for your specific lot and project. We use efficient design-build processes to keep design costs reasonable, and because we handle design and construction together, plan revisions do not bounce between separate firms and delay your permit.
Can an ADU in San Marcos be rented out?
Yes. Texas law and San Marcos city rules generally allow ADUs to be rented as long-term residential units. Short-term rental rules vary by zoning district and San Marcos has separate licensing requirements for short-term rentals, so confirm that use case before you design around it. We are not attorneys or zoning officials, and we recommend you verify current short-term rental regulations with the City of San Marcos directly before assuming that use is permitted on your parcel.
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Other services in San Marcos
Bathroom Remodeling→Kitchen Remodeling→Home Renovation→Home Addition→Home Builder→
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