







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Bastrop
A home addition in Bastrop typically costs $140 – $320 per square foot depending on whether we’re adding a bedroom, sunroom, or second story, and most projects take 3 – 6 months from permit to final walkthrough. We’re Seedling ADU Austin, and we coordinate every Bastrop job from our Austin office with crews who know the 71 corridor, downtown’s historic overlay, and the sandy soil patches left by the 2011 fires. When you call (254) 615-3842, a live person answers, and you’ll get a written price before any work starts. No voicemail trees, no vague estimates. Just a plan you can see in dollars before we pick up a tool.
Why Seedling ADU Austin Is Bastrop’s Preferred Home Addition Contractor Company

We’ve worked on additions across Bastrop’s distinct housing stock: 1920s bungalows off Linden Street, ranch houses in Tahitian Village, and new builds along the 71 expansion. Each one demands a different foundation approach, and we don’t treat them the same. The sandy, disturbed soil on post-wildfire lots drains unevenly, so we pre-wet trench lines in summer and spec helical piers where needed. That’s not something a generic contractor figures out on day one. It’s how we start the bid.
Every crew member who walks onto a Bastrop property is background-checked and uniformed. We bring shoe covers and drop cloths inside your home, and we send you a photo of the clean-up before the crew leaves. That’s the Cedarwell Care Promise, and it’s not optional. When additions run near bedrooms during school hours, we stage quiet work accordingly. Kids napping? We’ll do the loud cutting in the afternoon. We treat the job site like our own living room, because your family still lives there while we build.
Bedroom Addition Contractor in Bastrop
A bedroom addition in Bastrop runs $58,000 – $145,000 for a standard 300 – 500 square foot suite with bath, depending on whether the lot needs pier work or a septic capacity upgrade. We’ve done this exact job on a narrow lot off Linden Street, where a 300-square-foot bedroom suite went onto a 1920s bungalow using a helical pier foundation to bridge the sandy soil. The neighbor’s heritage live oak stayed untouched, because we ran a temporary silt fence along the property line before excavation started. That’s the kind of planning that keeps a Bastrop addition moving when the county starts asking questions.
Foundation and Soil Preparation
Bastrop’s post-wildfire lots often have soil that looks firm but crumbles when you dig. We test drainage early, pre-wet trenches in July heat, and spec pier or slab systems that won’t shift during drought or sudden downpour cycles. The foundation decision gets locked into your written price before we break ground.
Septic-Aware Square Footage
Adding a bedroom in Bastrop County can trigger a septic capacity review. If the system can’t handle the added fixture count, the county may require a replacement mid-project. We flag this before permitting, not after, so you’re not surprised by a $20,000 – $40,000 septic upgrade halfway through framing.
Sunroom Addition in Bastrop

A sunroom addition in Bastrop costs $38,000 – $85,000 for a 200 – 400 square foot finished space with cooling, and many homeowners choose it as a lower-cost way to add living area without the foundation complexity of a full second story. The local climate pushes the design: summer heat means high-efficiency glazing and a mini-split that keeps the room usable in August. Occasional intense rainstorms mean the drainage around the sunroom has to be handled deliberately, even when the county map shows no flood zone.
Glazing and Cooling for Texas Heat
We spec low-E glass and insulated panels that hold up to Bastrop’s 100-degree stretches without turning the room into an oven. The mini-split goes in before the room is finished, so your July and August afternoons stay comfortable.
Wildfire-Conscious Materials
Bastrop County’s wooded areas carry wildfire risk, so we recommend fiber-cement siding and metal edge details for sunrooms near tree lines. These choices meet local insurance expectations and hold up better than vinyl in heat and ember conditions.
Trusted Brands We Service in Bastrop
We work with Abodu, Cover, and Dvele for prefab and panelized additions when a Bastrop homeowner wants a faster enclosed shell with pre-engineered quality control. For site-built work, we use James Hardie siding and trim because it stands up to Bastrop’s sun and wildfire exposure. We stock common parts and panel sets locally, so a mid-project change doesn’t stall the schedule waiting on a shipment from out of state. You choose the product that fits your lot and budget, not just what we prefer to sell.
Common Home Addition Contractor Problems We See in Bastrop Homes
- Sandy soil trench collapse. Starting foundation work in July without pre-wetting the sandy soil leads to trench walls giving way and a costly re-dig. We pre-water and shore before we dig.
- Heritage tree conflicts. Bastrop’s protected live oaks and post oaks dominate many yards. An addition that threatens root zones can stall permitting, so we design around roots from the first site visit.
- Septic capacity surprises. A bedroom or bathroom addition can trigger a county-required septic replacement. We check system records before the permit application so the cost is in your written price.
- Historic overlay height limits. Downtown Bastrop’s 27-foot height cap for additions in overlay districts has stopped framing mid-job. We verify overlay boundaries before drawing plans, not after the first inspection.
Pricing for Home Addition Contractor in Bastrop, TX
A bedroom addition in Bastrop runs $58,000 – $145,000. A sunroom runs $38,000 – $85,000. A bump-out addition, which extends a kitchen or living room by 60 – 120 square feet, runs $28,000 – $55,000. Second-story additions start around $150,000 and go up from there, because they require structural reinforcement and often trigger the 27-foot height review in historic areas. What changes the price most: soil condition, septic capacity, tree protection, and access. A tight lot where we have to hand-carry materials costs more than a lot with driveway access to the foundation line. Every Bastrop quote comes as a written, line-item price before any work starts. Call (254) 615-3842 and we’ll walk your lot and put real numbers on paper.
We Also Serve Cities Near Bastrop
Our crews work throughout Bastrop County and into Elgin, Lockhart, Taylor, and Austin for homeowners who want the same written pricing and the same clean job site. If you’re in a nearby city and planning a home addition, our Home Addition Contractor team can help with the same thorough site review. Curious how we handle additions in other markets? See Home Addition Contractor in Bastrop for how we approach this specific area.
Serving Bastrop, TX - Our Local Coverage Area
We’re based in the Bastrop area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Home Addition Contractor in Bastrop
Generally, yes, if the addition sits close to a shared property line in an older Bastrop neighborhood with historic overlay or tight side setbacks. We handle the notice for you: written notification to the adjacent owner before excavation, plus a silt fence and root protection along the line. If a party-wall agreement is required by the city, we draft it and get it signed. Call (254) 615-3842 with your lot details and we’ll tell you exactly what your property needs.
The sandy, disturbed soil left by the 2011 fires drains unevenly and can settle differently across a single lot, which means your foundation needs a geotechnical check and often helical piers or a deeper stem wall. We pre-wet trench lines in summer to prevent collapse and design for both drought shrinkage and sudden rain saturation. The foundation approach gets written into your price before we dig anything.
Often, yes, if the garage’s foundation can carry the added floor weight and the tree’s root zone is protected during construction. We design the stair connection and structural reinforcement around the root zone rather than cutting into it, and we run a root-protection fence during the build. A structural engineer has to verify the existing slab, and that’s part of our site review. Call (254) 615-3842 to have us look at your specific garage and tree.
Bastrop’s residential work hours generally run weekdays from 7 a.m. to 7 p.m., with weekend work allowed but often with a noise restriction starting earlier in the evening in historic districts. We coordinate start times with your family’s schedule and the neighbors. If a baby naps at noon, we stage quiet work then and do the loud cutting in the afternoon. We tell the adjacent neighbors what to expect before framing week starts, which keeps complaints and stop-work calls off the job table.
A bedroom addition adds fixture count, and Bastrop County can require a septic capacity review before the permit clears. If the system is undersized, the county may require a replacement, which costs $20,000 – $40,000 and adds weeks to the timeline. We check the system’s current permit records during our first site review so the number is in your written price, not dropped on you mid-project. Call (254) 615-3842 for a free site visit and septic check.
Written by Ben Ortega, Owner at Seedling ADU Austin, serving Bastrop and surrounding communities.









