Therma-Tru Home Additions & ADU Nationwide

Therma-Tru Home Additions & ADU: The Woodland Hills Owner’s Guide

If you’re planning a home addition or ADU in Woodland Hills and your existing exterior doors are Therma-Tru, we can match the new entry systems, thresholds, and weatherstripping to your current setup while keeping everything code-compliant and watertight. Typical full-scope additions in this part of the Valley run $45,000 – $130,000, with separate ADU construction starting around $90,000 – $220,000 depending on size, foundation work, and site access. Most owners discover their Therma-Tru parts are failing during the planning phase, when the new roofline or slab elevation changes how the old door seals. What started as a draft near the hinge becomes a gap at the threshold once the new foundation settles.

Call (831) 290-6866

We stock Therma-Tru-compatible thresholds, door bottoms, astragals, and weatherseal kits on our trucks when we’re working additions or ADU tie-ins in Woodland Hills. Mason Remodeling Co Woodland Hills is an independent service provider. We are not affiliated with Therma-Tru, but we match their parts by model and swing pattern every week. Call (831) 290-6866 and we’ll come out, measure the existing opening, and give you a written price before any work starts.

Key Takeaways

• Home additions in Woodland Hills range from $45,000 – $130,000; ADUs run $90,000 – $220,000 depending on scope.
• Therma-Tru door matching requires the model number from the hinge-side tag, not just the door width.
• We can reuse most existing Therma-Tru slabs when the RO (rough opening) stays intact; only the frame, threshold, and seals need replacing.
• Every crew member arrives with a photo ID badge, uniform, and name-and-photo introduction before the visit under The Threshold Standard.
• Written price before any work starts, on every project, no exceptions. A 365-Day Done Right Promise applies to all work we complete.

Which Therma-Tru Models This Applies To

Therma-Tru doors fall into specific series lines, and the parts aren’t always interchangeable across them. The Smooth-Star, Fiber-Classic, and Classic-Craft lines each use different slab thicknesses and reinforcement points. The most common compatibility gotcha we see in Woodland Hills: a homeowner buys a replacement threshold for a Fiber-Classic door, but the slab is actually a Classic-Craft with a different sill anchor profile. It looks close. It doesn’t seal. The door leaks at the first hard rain.

To identify your door, open it and look at the hinge edge. There’s a white or silver label with the model name and a series code (something like “FC70” or “CC60″). That code matters more than the brand name. Take a photo of it. If the label is painted over or torn, measure the slab thickness and the sill width. We match parts by slab thickness (1-3/4″ and 2-1/4” are common on Therma-Tru), the sill profile (adjustable or fixed), and the swing direction. For aftermarket parts, we default to OEM Therma-Tru pieces when the door carries structural load or faces direct sun on the south or west side of a Woodland Hills home. In the Valley heat, cheaper aftermarket weatherstripping dries out and cracks within two seasons. For non-structural trim and shoe molding, quality aftermarket equivalents hold up fine.

We also stock compatible hardware across the other lines we work with, including KraftMaid cabinetry, Cambria and Silestone surfaces, though door hardware is specific to the entry system you already have.

Signs Your Therma-Tru Home Additions & ADU Is Failing

• Water pooling at the threshold after rain. The adjustable sill has settled or the weep holes are clogged. In Woodland Hills, the dry-season dust cakes into the weep channels, so when the winter rains finally come, water backs up into the interior floor.
• A visible gap of daylight under or around the door. The weatherstrip has compressed beyond recovery, or the slab has sagged on worn hinges. If you can see light, you’re also letting conditioned air out and Santa Ana dust in.
• The door sticks at the top corner of the latch side. Foundation movement, especially common where slab-on-grade additions meet older original construction, shifts the rough opening slightly. The door still works, but it binds.
• Drafts you can feel with the back of your hand around the perimeter. The corner pads or the sweep at the bottom have failed. This is the earliest sign and the cheapest to fix if caught before water damage sets in.
• Rust or corrosion on the hinge screws or the sill. Most Therma-Tru exterior doors use galvanized hardware, but in coastal-adjacent parts of Woodland Hills, salt air accelerates wear. Once the sill corrodes, the adjustable mechanism stops adjusting.

If you’re already planning an addition or ADU and your existing Therma-Tru door shows any of these signs, this is the time to address it. The new work will only make an existing problem worse.

Replacement Cost & What’s Included

For Therma-Tru-compatible door parts connected to a Woodland Hills addition or ADU, here’s what you’re looking at:

• Threshold replacement (parts + labor): $350 – $850, depending on whether the sill is adjustable and how much shimming the settled opening needs.
• Complete door bottom / sweep replacement: $120 – $300. We cut to width on site, no ordering needed for common sizes.
• Weatherseal kit (frame, corner pads, top rail): $200 – $500 installed.
• Full door replacement with new Therma-Tru slab and frame: $2,500 – $6,500, which includes removal, disposal, and re-trimming the interior casing.
• Full home addition (new framing through finish): $45,000 – $130,000.
• ADU construction: $90,000 – $220,000.

The wide range on additions and ADUs in Woodland Hills comes down to foundation type (post-tension slab versus raised floor), site access for equipment, and whether you’re tying into existing plumbing or running new lines from the street. Every quote we write is a line-item price, not a verbal estimate. You’ll see exactly what the parts cost, what the labor costs, and what the permit fees are. The 365-Day Done Right Promise covers all work we complete, stated as 365 days from the completion date on the written guarantee you receive.

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