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Get your free estimateFast, Reliable Home Addition Contractor Across Houston
Home additions in Houston typically run $85,000 to $220,000 for a ground-floor room addition and $160,000 to $380,000 for a second-story addition, depending on the condition of your existing framing, foundation, and the floodplain status of your lot. That range is not a guess. It is what our crews see week after week when we open walls in neighborhoods from Westbury to the Heights. If you are planning a sunroom, a bedroom bump-out, or a full second story, call (940) 242-3207 and we will give you a written price before any work starts, not a range you have to hope holds up.
Why Sutton ADU Houston Is Houston’s Preferred Home Addition Contractor Company
Houston homeowners deal with something most of the country does not: no formal zoning code. That sounds liberating on paper, but it means your addition is governed by deed restrictions, floodplain maps, and a 3,000-square-foot lot coverage cap that can shut down a project no one warned you about. Our crews build in this reality every day. We know which questions to ask the Harris County Flood Control District before we quote a single square foot, and we know how to read the private covenants that older neighborhoods like Meyerland and Braeswood still enforce. Lead by Miles Hartwell, our Houston team was founded in 2006 as part of the Threshold Group family, and every technician who walks onto your property is background-checked, identity-verified, and photo-badged. You get their name and photo before they arrive, every time.
Our Home Addition Contractor in Houston service area covers the full metro. We are in Bellaire, Humble, Pearland, and La Porte nearly every week. The work does not get subcontracted to a crew you have never met. The people who quote your job are the same badge-verified team who frame it, and the same ones who stand behind it for a full year under our written 365-Day Done Right Promise.
Sunroom Addition in Houston
A sunroom addition in Houston is not the same project it is in Dallas or Austin. Here, the sunroom has to survive a real summer, meaning a cooling season that runs from May through October and routinely pushes 5,000 cooling degree days. You are not building a passive glass box. You are building a conditioned space that has to hold 75°F in August on a slab that is sitting on expansive clay. Most Houston sunrooms we quote run $65,000 to $145,000 for a 200- to 400-square-foot room with its own HVAC zone, insulated glazing, and proper moisture barrier detailing.
Why Houston Sunrooms Need Their Own HVAC Zone
Running one more supply line off your existing system rarely works here. The existing unit was sized for the original square footage, not an extra 300 square feet of south-facing glass. When we tie a sunroom into a shared system, you get a room that cannot hold temperature and a main house that starts cycling too hard. We specify a dedicated mini-split or small heat pump with a dehumidification mode, because Houston’s humidity is the real enemy, not just the heat.
Floodplain and Foundation Checks Before the Glass Goes Up
Some Houston sunrooms sit on lots where the finished floor has to be elevated or fitted with flood vents to satisfy Harris County rules. We check the floodplain map before we quote, not after. And because much of Houston sits on gumbo clay, we will often add engineered piers or a thickened-edge slab with rebar to keep your sunroom from moving independently of the house over time.
Second Story Addition Contractor in Houston
A second story addition in Houston costs between $160,000 and $380,000, and the single largest variable is not the framing package. It is what we find when we open up the first-floor walls and ceiling. On a 1950s ranch in Westbury, our crew opened the garage wall to tie in a 400-square-foot second-story addition and found the original top plate had rotated under hurricane ties that were never installed. We pulled a permit, added two new 6×6 posts with Simpson Strong-Tie connectors, and documented the change order before any new framing went up, because the existing slab step-down would have put the new floor four inches out of level. That is how we work.
The Lot Coverage Rule Most People Miss
Houston caps building coverage at 3,000 square feet of impervious surface on many standard lots. Go over that and you trigger stormwater detention requirements, which can add $15,000 to $40,000 to a project in a hurry. We calculate your existing footprint before we design the addition, because a second story is often the only way to add square footage without crossing that line. Ground-floor additions are the ones that get homeowners into trouble.
Garage Apartments and the Heights Question
Older inner-loop neighborhoods like Montrose and the Heights are full of garage apartments built in the 1920s through 1940s. Many have 2×4 rafters, no shear wall, and footings that were undersized when they were poured. If you want to add a second story over one of these, the inspector is going to look at the existing structure, not just the new framing. We reinforce or replace what is there before we build up, and we tell you what that costs before drywall goes on, not after a red tag.
Trusted Brands We Service in Houston
We work regularly with prefab and modular systems from Dvele, Plant Prefab, and Boxabl, and we have built enough of them in Houston to know which panels handle our humidity and wind load requirements without delaminating or sweating at the seams. A Plant Prefab panel set that works fine in California needs different detailing here, particularly at the sill connection and the roof tie-down. Our Home Addition Contractor team stocks the fasteners, flashing, and sealants these systems require locally, so a missing bracket does not hold your schedule hostage waiting on a freight shipment.
Common Home Addition Contractor Problems We See in Houston Homes
- Rotated top plates and missing hurricane ties. Homes built before wind load codes were tightened in the 1990s often have framing that was never properly tied. When we open a wall, this shows up fast. We fix it, document it, and price it in writing before framing continues.
- Slab step-downs that are inches out of level. Houston slabs move. Clay soil expands and contracts, and 50-year-old slabs are rarely flat. A new floor tied to an out-of-level slab creates a visible transition and a structural headache. We measure, shim where needed, and tell you the cost before we pour or frame.
- Sunrooms and additions without a separate moisture barrier. Houston sees 50 inches of rain a year and humidity that rarely drops below 60 percent. A slab or crawlspace without proper poly and drainage detailing will sweat, mold, and fail fast. We do not skip this step, even on a small bump-out.
- Quotes that ignored the floodplain map. We see homeowners holding a bid from another builder that never mentioned flood vents or elevation. Then the permit review flags it. Then the price jumps. We check flood data before we quote, so the number you get is the number the permit office will actually approve.
Pricing for Home Addition Contractor in Houston, TX
Here are the ranges we give Houston homeowners before we do anything else:
- Sunroom addition (200 – 400 sq ft): $65,000 – $145,000
- Ground-floor bedroom or bump-out addition (300 – 600 sq ft): $85,000 – $220,000
- Second-story addition over existing living space: $160,000 – $380,000
- Second-story addition over a garage apartment or detached structure: $200,000 – $420,000, depending on reinforcing the existing footings and framing
What moves the number: hidden conditions we find when we open walls, floodplain requirements, the condition of your slab, and whether your existing HVAC can carry the new load. Every Sutton ADU Houston quote includes a written contingency allowance for exactly these items. If we do not use it, you do not pay it. Call (940) 242-3207 for a free estimate with the full line-item breakdown.
We Also Serve Cities Near Houston
Beyond Houston proper, our crews work regularly in Bellaire, Humble, Pearland, and La Porte. Each has its own permitting quirks, from Bellaire’s strict tree protection rules to Pearland’s newer floodplain overlay. If you are adding square footage anywhere in the metro, call (940) 242-3207 and we will tell you what applies to your specific lot.
Serving Houston, TX - Our Local Coverage Area
We’re based in the Houston 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 Houston
Because older Houston homes hide things. Rotated top plates, missing hurricane ties, out-of-level slabs, and outdated wiring are common in homes built before the 1990s. A contingency, typically 8 to 12 percent of the contract, covers those findings without stalling your project. If we do not use it, the money stays with you. Call (940) 242-3207 and we will walk you through how the allowance works in writing.
Not usually for the second story itself, but the existing first-floor structure and any new ground-level work can be affected. Harris County floodplain rules often require flood vents or elevation on the lower level if you are modifying it. We check the floodplain map during quoting, so the permit review does not blindside you. Call (940) 242-3207 and we will check your lot before you commit to a design.
Yes, but it depends on what the existing structure can carry. Most Heights garage apartments from the 1920s through 1940s have undersized footings and no shear wall, which means reinforcements before any vertical framing. That typically adds $30,000 to $70,000 to the project. We inspect, engineer, and price it before we touch the roof. Call (940) 242-3207 and we will come look at your garage apartment.
Houston caps most standard lots at 3,000 square feet of impervious surface, including the house, driveway, and any additions. A ground-floor addition that pushes you over that line triggers stormwater detention, which can cost $15,000 to $40,000. Going up instead of out often avoids this entirely. Call (940) 242-3207 and we will calculate your current footprint before you decide which direction to build.
Because Houston’s cooling season is brutal and long. Your existing system was sized for the original square footage, not an extra 300 square feet of glass. A separate zone, usually a mini-split or small heat pump with dehumidification, lets the sunroom hold temperature without overworking the main unit. Call (940) 242-3207 and we will spec the right unit for your room size and glass orientation.
Written by Miles Hartwell, Owner at Sutton ADU Houston, serving the Houston metro area under the Threshold Standard since 2006.
